Soundproofing vs Sound Absorbing – What’s the Difference?

You want to do what?

When someone has a noise problem and doesn’t know what, why, who, or how they begin scouring the internet looking for “soundproofing”. I have been getting a lot of calls lately from these people. They explain to me that they want sound that is being made within the room to stay in the room or they want to keep sound out of their space. We commonly begin talking about the room and the type of noise that we are dealing with in each particular situation.

A lot of people ask for pricing on “soundproofing foam”, sound absorbing foam, or sound proofing panels. They are sure that foam is the ticket because people have seen “egg crate” foam or other similar products as finish wall treatments in recording studios, on TV shows and in movies. This misconception is incredibly common – so if you are reading this thinking to yourself, “Well, self, doesn’t foam stop sound? Isn’t foam used for soundproofing a room? Everyone knows that, right?” Unfortunately I have to tell you that you are wrong. Foam does not stop sound, foam absorbs echo. Don’t feel bad. There are lots and lots of people out there that share this idea.

There are two sides of the acoustical coin, if you will. There are products that absorb echo within a room and there are products that will block or stop a sound. (There are some panels that will do both. These are generally called composites, but if I get into that now, things will be confusing so I am going to keep it simple.)

You Can’t Build an Aquarium With Sponges

I came up with an analogy that I have found useful in helping people understand this whole idea in a very generic way. Imagine you are building an aquarium.  You want to keep the water in, right? I know I do, at least. What do you think will be more effective, glass panels and seals or pillows and sponges? Sound acts very similar to water when you are trying to control it. If you used sponges as the walls, they would fill with water and let all of it through to the other side. Now if, instead, you used thick glass and good seals, that would keep the water in place. Acoustical materials made from soft, squishy things like sponges are going to absorb. Dense, heavy, air-tight glass will block. That is the basics right there. Now you can impress all your friends by knowing this. Let’s dive more into the specifics.

Absorbing NoiseAbsorbing

Products that are designed and intended to absorb echo within a room are soft, light, fluffy products. They will generally feel soft to the touch. They are designed to soften up the surfaces within a room and reduce the echo in that space.

I like analogies, I think they help people visualize and relate to an idea, so here goes another one. Let’s say you are finishing a room in your basement. You have installed the studs that will frame the wall and you are to the point where you are ready for sheetrock. Instead of using sheetrock, though, you decide you are going to put up some 2″ thick “egg crate” foam on the studs. Keep in mind this foam has almost no mass or density, it is mostly air. After you’ve got this installed, you tell one of your helpers to go stand on the opposite side of the wall and begin talking. You will be able to clearly hear each other as if there were no wall in front of you.

BlockingBlocking Noise

Products that are designed to block sound from entering or leaving a space are almost always found inside the wall construction. These products are heavy, dense, cumbersome, or designed to decouple the wall so that one side of the wall doesn’t have hard surface contact with the either.

Remember that last analogy? The one in your basement? Let’s go back there. Now, instead of foam this time, you decide it would be a better option to use 9 layers of 5/8″ sheetrock on either side of the wall. Nine layers on the inside, nine layers on the outside. You send your help to the other side again and have them start talking. I would be willing to bet that you can not hear much of what they are saying because you have added so much mass into that wall.

Echo...Echo..….Echo….…..Echo…...…..Echo

You guessed it, I’ve got another analogy! Let’s head to the gym. It’s currently under construction because they are adding some real nice racquetball courts. Let’s check them out. The room is made out of concrete and is the size of a standard racquetball court – 20′ wide x 40′ long x 20′ tall. The walls of this room are two-feet thick. You clap your hands in the room and the echo seems to go on forever. Let’s have some fun in here. You have, in your hands 100 new super bouncy balls of varying colors. (You must have really big hands.) You throw them in every direction and they keep bouncing and bouncing everywhere through the room. After a few minutes, they eventually stop bouncing and hopefully you remembered to wear your helmet or you may be dealing with a big headache. Now imagine that you brought some 2″ thick foam with you. You line the walls, ceiling and floor. After that is done, you throw the same 100 super bouncy balls. This time when they hit the wall/ceiling/floor they don’t bounce. The energy from the ball was absorbed into the room, more specifically, the foam. A sound wave inside this room is just like that super bouncy ball. It will reflect, or “bounce”, of any hard surface but will be absorbed by a soft surface.

Now what?

If you made it this far, I congratulate you for making it through my fairly crude examples. My intent was to help paint a picture to help you understand more clearly the general differences between absorbing and blocking sound (soundproofing). I’m sure there are lots and lots of people out there that are excessively smarter than I am who are shaking their heads because I did not touch on the technical side of things – explaining wavelength and frequency, etc. I don’t care. I am trying to simplify things to give those non-technical individuals a basis to begin educating themselves on their noise problem(s).

Of course, you aren’t going to be an expert in acoustics now. This is a start. For your next step, I would recommend finding an expert or at least someone who knows the specific products that you can use for your specific situation.

So, before talking with that person, I would have these questions answered:

  1. Are you looking to block sound or absorb echo?
  2. What are the dimensions of and surfaces in your room?
  3. What is the room used for, what types of sound(s) are you looking to block/absorb?
    (a high pitch-squeaky sound, voices, low frequency-bass type sound, all of the above)
  4. What are your ideas as to the best way to treat the room, where to put product, or how to approach the situation?

I know this is not an all encompassing list, so I will not feel bad when you leave me a comment that I forgot something. In fact, I encourage it.

Here are few sound absorbing products:

  1. Fabric wrapped acoustical panels
  2. Sonex Classic acoustical foam panels
  3. Wallmate stretch wall system

Here are few sound blocking products:

  1. Soundbreak XP soundproof sheetrock
  2. Mass loaded vinyl barrier also known as MLVB
  3. RSIC-1 Clips resilient sound isolation clips

291 Comments

  1. Ted W

    Maria,

    Good morning and thank you for the E-mail. I would be happy to help put together a low-cost and creative way to help the busy salon, it shouldn’t be any problem at all to figure out something that works. I do, however, need to get some more information about the situation to really be able to help. I would assume that this is a fairly large room that is made up of hard surfaces and you are looking to “take the edge” off of the space so that it doesn’t get so loud.

    Assuming this is the case, I will need some information about the room itself. Either exact or fairly close measurements of the height, width and length of the room as well as a list of the surfaces that make up the room. Floor, walls, ceiling, etc. A few digital pictures (even those taken and sent via cell phone camera) are REALLY great. If you have partial or half walls, or if the space is broken up in some way, we can discuss that together if you would like. Also, if you are trying to work with an existing or desired aesthetic, that can help me as well. If the panels or product NEEDS to be a specific color or something, run that by me as well.

    Based on the quick description of the “inexpensive” goal, my first suggestion is the Echo Eliminator panels which are a very economical option. These panels are made from recycled cotton fiber and kind of resemble a one-inch thick piece of felt. They come in 2’x4’ panels and are usually installed on to the walls or ceiling with construction adhesive, but we can grommet them for a less-permanent type of installation. They are in-stock in nine different colors and will ship via UPS in just a few days.

    The next two questions are very standard. (1.) How many panels do I need and (2.) Where should they be installed?

    The question of how many panels to install is simple and very complicated at the same time. The complexity stems from the fact that the “proper” acoustic of a room is EXTREMELY relative to the room itself, the use of the room, the occupants preferences, the clientele, etc. Different rooms have different uses. Some are just fine being relatively loud and some need to be very quiet. So, there is no “easy” answer to this question. I have, however worked with enough acoustical software as well as real-life situations to comfortably apply my “cubic volume x 3% = square footage to install” equation.

    Height x width x depth = cubic volume of the room
    Cubic volume x .03 = square footage to install.

    Where the panels are going to go is an easy one – wherever you would like. Generally speaking you can install the panels on the walls or the ceiling in any pattern to get the same general reduction of the ambient (background) noise level in the room. Sound travels at 1,126 feet per second so by the time you’ve clapped your hands three times, the first clap has reflected off of the walls, ceiling and floor a few hundred times. Sound simply travels too fast for the exact location of the material to make any real difference. If you think that the panels will look best on the walls – great, go for it! If you feel that the panels will really hide if installed on the ceiling? Sweet, ceiling it is. If you are considering hanging the panels as baffles (hanging from the ceiling like a flag), watch out for fire-suppression sprinkler heads and effects on the lighting.

    I have posted a couple times on the blog about Hair Salons, you can read these articles to see if they help you out at all, too.
    -Dealing With a Noisy Hair Salon
    -Salon Noise Problem

    Let me know what additional questions you have.

    -Ted

  2. Bob Dove

    Thanks for the info! I love the way you teach us newbies the beginning steps toward doing what’s right with sound problems. What I’m trying to do is build an 8×8 sound proof and sound absorbing recording booth in my apartment. I know an apartment is not the ideal scenerio, but it’s all I have to work with now (the 8 ft. ceilin is too low and other issues). Eventually I’ll get a home, but for now, I really need to keep the outside noise outside and keep intruments (like saxophone and vocals inside the booth). Again, it’s not ideal acoustically, but for now this is all I can do. Any suggestions?

    • Ted

      Bob,

      Good afternoon and thank you for posting the blog comment earlier this week. This may be a bit of a tricky situation for a few reasons but I will do my best to offer information that should help. In order to keep the neighbors from complaining, you are going to have to build a room within a room and float the whole thing on a layer or two of rubber so that this new “room” isn’t touching the floor. The tricky part becomes getting fresh air into the space. I would suggest using a 2×6 stud for the walls with a layer or two of 5/8” sheetrock (drywall) on the outside, some kind of thermal insulation on the inside and then two more layers of 5/8” sheetrock. Install a heavy, solid core door and be sure to use sealant to seal the rough opening to the studs. You are going to need to build some kind of lined duct or chamber to pull or push fresh air into the room as well as to return it to the rest of the air in the apartment. If this isn’t done correctly, it can quickly negate the walls ability to block sound.

      I get a lot of calls from people that want to put up soundproofing foam or some other simple, cheap and easy product onto the walls of the space because they see egg-crate or pyramid foam on the walls of recording studios and on TV in “soundproof” rooms. Please understand that the only thing that foam (or other similar wall treatments) does is to absorb the reflective noise inside of the room – it does not block sound from entering or leaving the space. You are likely going to want and/or need some acoustical panels in the space so that you are not playing or singing in an echo chamber, but I wanted to approach the “cheap and easy” situation as it comes up quite often

      Let me know what additional questions you have.

      Ted

  3. wade

    Extremely helpful, saved me alot of time and money! and it was in an easy to understand language! Thanks a ton! Great Blog

  4. Sue

    I have a tricky question for you…my teenage daughter needs to wear a heart monitor because she is having episodes of irregular heart beats. Here’s the problem…she’s a teenager and refuses to wear the device because it produces a high-frequency sound (like a fax tone) when it is recording. She only gets the episodes when playing sports–like tennis, so I agree with her, it would be quite a distraction. Any ideas as to what I could place the device inside of (it’s about 4″ x 3″) to reduce the sound transmission? Thank you so much!

    • Ted W

      Hi Sue,

      This is quite an interesting question! I’ve been here for almost 10 years now and haven’t had this request before. :-D I love new challenges and applications, though.

      We may have something that will help out, but I will need more information from you.
      -How large is this monitor?
      -How/where does she wear it?
      -Can you check with your doctor to see if we can wrap it while she’s playing sports?

      In order to block to sound, we’re likely going to need to enclose the machine. Depending on the machine, it may need to breathe (air-cool itself) so the thing doesn’t overheat causing failure. I don’t know anything about heart monitors, so I may have additional questions after these, but this should get me going.

      If any other readers have experience with heart monitors and the possibilities of enclosing them, please chime in. Thanks!

      • Sue

        Hey Ted,
        The heart event monitor is about 4″x3″ by 1/2″ thick. It clips on the waistband of her shorts and has two wires coming out of the top, which are attached to sensors placed on her chest. When she has an ‘episode’ she needs to depress a button on the front of the monitor so that the device will ‘record’. She will not wear this monitor permanently, just until they can record some episodes. It can be wrapped and does not produce any heat, as it is just ‘recording’ the heart’s electrical activity when the button is pressed. Thanks so much!

        • Ted W

          Hey Sue,

          This is going to be a little tricky, but I would like to try to come up with something for you. The tricky part becomes the fact that in order to block/contain sound, the product that you use between the noise source and the ear needs to have as much mass and density as possible. I wouldn’t want to make this thing too heavy as that would also be distracting. I’m running through a list of potential products in my mind and considering that this thing is worn on the waist band. I am coming up with a loss… The products that I have that will do a decent job are heavy. The products that I have that are lighter are likely going to be quite uncomfortable if in contact with the skin…

          Let me roll this one around a bit and I will do my best to get back to you quickly.

          Thanks,
          Ted

  5. Chrissy

    I live in a second floor apartment of a duplex. My neighbor plays the radio and tv at the same time in both the bedroom and living room creating an extremely loud and annoying echo in my apartment. I obviously cannot install anything in the walls or rip up the carpet, but I was wondering if there is anything I could use to absorb the echo to keep it out of my apartment.

    Thanks
    Chrissy

    • Ted W

      Hey Chrissy,

      Your problem is a relatively difficult situation based on the circumstances and limitations. I will start by explaining that I fully understand that you are not looking for total and absolute silence and that you would be happy with any noise reduction at all – I get it. The difficulty is due to the fact, as I explained in the article, that there is a big difference between absorbing and blocking sound.

      Absorbing the echo in your space will, in fact, make your space more comfortable will less echo. It will also make your space quieter, which may very well make the problem more noticeable. When you are sitting in a quiet listening environment it doesn’t take much for your ear to pick it up because there is very little other noise to distract you. If you want to try to get a few panels into your space, I would be happy to help you look into that option. In my opinion, though, unless the echo in your room is quite bad, this approach is not likely to make an audible difference.

      In order to start to reduce the problem, even a little bit, it is going to require adding “something” to the ceiling/floor assembly. This means that you would have to pull the carpet, install underlayment and re-install the carpet on top of it. There is not a finish flooring that can be put down on top of your carpet that will help this situation – I’m sorry.

      Noise problems within shared wall/floor situations usually require the most amount of work to resolve. Unfortunately, these are the situations where no construction is allowed by the person actually living in the space. The problem is best solved before it has become a problem – with the construction of the units.

      Please let me know if you have any more questions.

      Thanks,
      Ted

  6. Tom

    Hi Ted, My company is contracting to do a home improvement for a customer which adds living space to the basement of a bi-level home. Currently the wood floor above transmits sound (walking etc.) to the basement below without interference. It also transmits heat from the basement to the level above (floors) without interference. When we install a ceiling in the basement, we will interfere with both transmission of sound and heat. The customer desired to deaden the sound transmission (from the floor above to the basement), with minimum heat transfer loss. They want the heat from the basement to convect and conduct up to the floor above. The basement ceiling currently consists of open (2×4) trusses which form the floor above. These ceiling trusses are approximately 24″ height. We will be installing a sheetrock or similar ceiling (on the bottom of these trusses) leaving a dead air space between ceiling and the (wood) floor above. What would be the best ceiling material for the basement to both stop sound, yet allow heat transfer to the floor above?

    • Ted W

      Hey Tom,

      Unfortunately your customer is going to need to make a decision about which is more important to them – sound isolation or heat transfer. You cannot have one and not the other. If you want to stop sound, you’re going to stop heat transfer. If you want heat transfer, you’re going to have to live with a sound problem. That’s just the way things work, I’m sorry. Also, I am not really an expert in thermal conductivity through a structure, so I am not going to be able to offer much help there.

      I would suggest using the RSIC-1 clips or the RSIC-1 low-profile clips to float a ceiling off of the joists. I would absolutely still use a standard fiberglass or cotton-based insulation in the joist cavities. If this were my place, I would first use a bead of acoustical sealant on the subfloor (for the first floor) before I did anything, to make it airtight (since this approach is not going to allow for heat transfer anyway), so I would block as much sound as I could. I would finish the ceiling (below the RSIC-1 clips and hat channel) with two layers of 5/8″ sheetrock, use the same sealant around the perimeter of the new ceiling and finally tape, mud and paint.

      If thermal conductivity is more important than sound transfer, I would simply leave the ceiling as it is because you can’t do both in this situation.

      Let me know if there is anything else I can help with.

      Thanks,
      Ted

  7. Mark Watkins

    Noisy house HVAC blower mounted in closet next to living room. From your article I need absorbing material. Place it around unit as possible. What about the air intake side? Can I creat “louvers” of absorbing material? Say 2″ wide strips, half inch apart, placed at 45 angle to absorb noise from that side? Thanks.

    • Ted W

      Good morning Mark and thanks for the comment.

      HVAC closets are frequently problematic because you have a relatively loud machine in a very small room surrounded by hard surfaces and a basically open doorway. When the machine is surrounded by hard surfaces, the sound coming out of the louvered door is not only the direct-line noise going out of the front of the machine, but the reflected noise pours out too.

      I have had a lot of people start by installing an absorptive product on the walls to the sides and behind the machine simply to reduce the amphitheater-like effect that the closet has. This is often a very low cost, easy-to-install and relatively effective way to reduce the noise. The Echo Eliminator or Quiet Liner are usually the products of choice to do something like this. If you do not have a preference of what the product looks like and want to save a couple of bucks, I do have a fair amount of the Echo Eliminator on our discount/overstock/scratch-and-dent site.

      The door, on the other hand, is a bit more difficult. Ideally we would want to install an air-tight, solid-core wood door and eliminate all of the gaps and cracks around and under the door. This is obviously not going to happen as the machine needs the airflow through the door to operate. There are a few things people have done in the past to eliminate the straight-line path from the inside to the outside of the closet. It is always better to install the absorptive panels first, take a step back, and re-assess the situation. If it is decided that you then need to reduce it further, let me know and we can run through your options then.

      Thanks,
      Ted

  8. Tapan Kulkarni

    hi, there! I play drums at home and it has been troubling my neighbors and i often get complaints. I’ve a room at ground floor which has only one window and all other sides made of concrete walls. I come home from work at night, so i was looking for a room which is completely isolated to the outside world so that i can play the instrument at night without disturbing my neighbors. Please find me a solution which cost efficient too.
    thank u!!!

    • Ted W

      Hello and thanks for the comment!

      Unfortunately the situation that you are experiencing is INCREDIBLY difficult and will require a significant amount of work and modification to the construction to achieve “complete isolation from the outside world”, especially considering you are playing the drums.

      To accomplish this, you are likely going to need to build a ‘room within a room’. Even with that, listeners in close proximity will be able to hear and feel the bass drum. There is not a cost-effective way to do this because of the type of pressure of the sound you are creating with the drums.

      I would be happy to look into it with you, but just want you to know this is likely going to be a difficult and expensive problem to try to tackle.

      Thanks,
      Ted

  9. Joe

    My new ranch home has an open floor plan throughout and the living room area is full of echo. Our living room is 19′ x 24′ with a vaulted ceiling that is 8′ at lowest and 14′ at peak. On the short walls, 8′ is taken by window space on one wall, and 8′ open to another area on the other wall. On one of the long walls, 8′ is open to another area. We have a beautiful view so don’t want curtains on the window. The room is heavily carpeted and I am planning on purchasing a large fabric tapestry to hang. Wondering if any of your products placed behind the tapestry would add additional sound absorbsion. Any other suggestions? Thanks for the great blog!

    • Ted W

      Hey Joe,

      Thanks for the comment.

      I am contacted relatively frequently from people in similar situations where large, beautiful rooms (constructed with materials of generally hard surfaces) have sound/echo/reverberation problems. Unfortunately there is a direct relationship between the size (cubic volume) of a room and the surfaces that make up this space and echo or reverberation time that it has.

      Very roughly, based on the dimensions that you provided, I would suggest starting with 150-200 square feet of absorptive material in the room. You could always start with the tapestry, take a step back, listen and re-assess the situation. The reduction in reverb is going to depend on the size and thickness of the fabric.

      Regarding your question about backing the tapestry with a product to increase the absorption, that is going to depend significantly on the tapestry itself (physical properties) and the distance from the wall. I would also want to find out whether or not the addition of the fabric made any audible difference in the space.

      If I were to line the back of the tapestry, I would install our Echo Eliminator cotton panels behind it.

      Let me know if you have any other questions. I would also be curious to know how adding the tapestry affects the space.

      Thanks,
      Ted

  10. Wendy

    Hi. I would like to find out how to keep sound out of a room. I have several family members staying with me right now and the kitchen is adjacent to my master bedroom. My husband is disabled and needs to get lots of rest and has not been able to since they’ve been here. The dimensions of my room are 17×33. There is one wall 33 long that is adjacent to the kitchen. Is there anyway I can just do something with that one wall to make any kind of difference? Thanks!

    • Ted W

      Good Morning Wendy,

      Thanks for the comment.

      Keeping sound out of a room really needs to be approached in a way specific to the room in question – there isn’t a standard way to approach all situations. So, before we start talking about how to treat this room, I would suggest putting a fairly constant noise source (like a radio) in the kitchen and going into the bedroom. Then critically listen to exactly where the sound is leaking through – and get back to me with that information. This is best done when the house is empty and relatively quiet. I would suggest focusing on the duct work (supply and return vents), the gaps and cracks around and under the door, and any outlet boxes on the common wall.

      If it is the wall, itself, we do have quite a few products that will help reduce the sound coming directly through the wall – each with its own advantages and disadvantages. Almost all of these things are construction-grade products that work with sheetrock. This means that you will need to do a bit of construction to that wall to get some reduction. We do have a few panels that would help, but they are generally fairly expensive and you will need to cover the wall completely.

      So, please let me know your findings about where the sound is leaking through and let me know if you have more questions.

      Thanks,
      Ted

  11. Riaz

    Dear Sir,

    We are manufacturer of acoustic (sound proof) enclosure for the diesel generator sets.
    We need sound proofing foam / material for the reduction of the sound level of the machine built / Generator set fixed inside the enclosure.
    You are requested to please advice which kind of foam you recommend for this use.

    best regards
    RAK

    • Ted W

      Hey Riaz,

      Thanks for the comment. Unfortunately I can not make any recommendations until I have some more information from you.

      Enclosures are always very problem, situation, and location specific. There isn’t a one-all, be-all liner for an enclosure.

      I will need to know where you are located. What are the conditions that the products needed will face? I will also need to know more about the enclosures you are proposing to build. Where are these machines being used and what type of dB levels and frequencies will be predominant?

      Thanks,
      Ted

  12. Renata

    Hi, Ted! I love your blog, thanks for the very informative articles! So I need some help, can you please work this out with me? I live in a condo with thin walls/ceiling/floors and I´m bothered by both my downstairs and my upstairs neighbor (ha! Should I just move? :-) Anyway, I´ve been researching this soudproofing issue a lot and have already done some work to block sound from the outside to my bedroom but it just hasn´t help as much as I expected. My situation now is:

    1) ceiling: my neighbor from above bothered me with both loud music/loud TV and impact noise. What I´ve done so far: I decoupled the ceiling with resilient sound clips, put some absorbing material in the air cavity (rockwool) and a layer of drywall (1/2″ thick) with MLV (a bit thicker than 1/16″) bonded to it. We tried really hard not to let the drywall touch the walls and sealed the perimeter with acoustical caulk. Seems like it worked pretty well since it muffled the sound quite a bit but I still can hear voices and both TV and music, so I´m thinking about adding another layer of drywall with green glue this time. The impact noise was just somewhat better, as I expected, but it´s good enough not to wake me up anymore very early in the mornings and I guess green glue will help a bit more so I think I´ll just have to deal with whatever is left of it;

    2) floor: my downstairs neighbor bothers me with very loud TV untill late at night and I really thought this would be the easiest problem to address. However, it seems like it´s my biggest problem now! What I´ve done: over my old tile finished floor, I laid 2 layers of 1/16″ MLV (I didn´t let the seams of the second layer meet the seams of the first one) and then finished the floor with wood laminate. I didn´t have the chance to seal the perimeter with acoustical caulk prior to installation of the baseboard, but if you think that´s an important step I´m willing to remove them, caulk the perimeter and reinstall them.

    Ok, so what is my problem now? The thing is the TV from my downstairs neighbour is still VERY audiable. It´s still loud and I can still tell what program he´s watching down there, even though it´s not as loud as before. It seems to me that I´m dealing with flanking noise mostly in two walls, the one behind my bed and the one by the side of the bed I sleep (I believe his TV is right in the corner of these two walls since sound is a lot louder on both of them than on the other walls of the room). Is decoupling these walls mandatory in order to stop this annoying sound of his TV from getting into my bedroom?? I actually do have the room to decouple the wall behind my bed, but not the one beside it – so how do I treat that one? Also, do you think that treating these two walls only will significantly help me or do I need to treat the whole room? This is driving me crazy, specially now that I´ve spent money and put a lot of effort into soundproofing… Could you please, please help me?? Thank you very much for your time and attention! Best regards, Renata

    • Ted W

      Hey Renata,

      It sounds like you have gone to some fairly extensive lengths to soundproof your condo. I am so sorry to hear you are still having problems. Where are you located? It might be worth having a local acoustical consultant in your area make some recommendation on what to do next. If you can clearly make out voices and determine what TV show your neighbor is watching, there may be some fairly complex structural issues. I would hate to see you throw more time and money into this problem and not make enough of a difference.

      I would be happy to help you find someone local that may be able to visit your place and make some recommendations, if you would like. The unfortunate part about some situations is that it’s impossible to help people try to fix the sound problems because I’m not there.

      Let me know if I can help out in any way,
      Ted

  13. SherryD

    I share a common wall in a condo with a family with three children who are constantly jumping and running down the stairs and across the floor. It is driving us crazy. Our couch is on the common wall and we can feel the vibration. Is there anything I can do that would cut down the BOOMs we hear periodically throughout the day? I realize impact noise is the hardest to alleviate. I was thinking of green glue and another piece of drywall and rearranging our living room to put the tv on that wall and the couch all the way across the room.

    • Ted W

      Hey Sherry,

      Thanks for the comment. I am sorry to hear about your situation! You are exactly correct in your mention of the fact that impact noise is the most difficult to alleviate. This is because of the massive amount of energy that is travelling through the structure. In order to reduce the boom that you are hearing, you really need to try to stop the energy at the point of impact.

      Picture the difference between these three different situations:

      • Dropping a bowling ball directly onto the floor and standing a few feet away
      • Dropping a bowling ball onto a pillow and standing a few feet away
      • Dropping a bowling ball onto the floor and standing ON the pillow a few feet away

      Once that energy is into the structure, everything touching that structure is subject to that energy via hard-surface vibration energy transmission. Depending on the severity of the problem and the engineering of the structure, you might get some reduction by installing Green Glue and an additional layer of sheetrock over your existing wall. Or a layer of SoundBreak XP. You could also reduce the amount of vibration that you are feeling in the floor by getting some of the Acoustik underlayment down under your finish floor. The amount of reduction is going to be very much based on those two things, the severity of the problem and the structure itself.

      Please let me know if you have any more questions,
      Ted

  14. Dan

    Thanks for the analogies. They are very helpful. We often run into similar problems when dealing with outdoor noise in the landscape. People think that plants absorb noise but they do not. Leaves rustling in the wind can mask noise, as can water fountains, however as you’ve pointed out with the sponge idea, leaves just let noise pass right through. There are some interesting psychological examples where plants (and other structures) can make noises seem less loud by hiding the noise source (eg air conditioner or busy street) from view.

  15. howard johnson

    I have a vacuum pump motor inside a machine shop. Its measurements are 13.5″ high 16″ wide and 39″ long. This motor is very load and run hot. Any suggestions on how to “block” the noise and having enough air flow?

    • Ted W

      Hey Howard,

      Thanks for the comment.

      Motors that run hot can be tricky to try to quiet down, but it’s absolutely something that is possible. The “best” approach is going to depend on not only the amount of sound that you need to block (how quiet you need the end result to be) as well as the amount of air that the machine needs to stay cool enough to operate.

      I will make a few assumption here. If I am completely off base, let me know so that I can alter my recommendation. If you would like to send pictures of the pump, I would be happy to have a look.

      These are my assumptions:

      1. These pumps are usually in corners or tucked somewhere in the shop along the wall.
      2. There are pipes/hoses that are connected to the pump.
      3. The pump is mounted directly onto the ground – or on a ground-mounted frame.

      The real variable that I have found throughout the years is the frequency (pitch) of the noise being generated and that is going to have a significant impact on what type of treatment you will need to build or use to get this where it needs to be.

      One common approach would be to put an absorptive panel or two (usually the cotton Echo Eliminator panels) on the wall or walls behind the machine and put two (if it’s in a corner) or three (if it’s along a wall) free-standing walls right in front of the machine, making sure that the height of the walls is no less than 2x the height of the noise source. In this case, 27-30″ tall would be ideal. I would then suggest putting some absorptive panels on the back side of the walls. For the free-standing wall construction, I would suggest the heaviest board-type material you can find. MDF, plywood with sheetrock glued/screwed to it, etc. The heavier the better.

      This is usually the preferred way to start, because it allows for all of the heat being generated by the machine to escape upward.

      Full enclosures, sometimes power-vented, are also a possibility and will always outperform a wall-type enclosure. They do have their own challenges, though. I have also seen instances where people have used plywood, four eye bolts and aircraft cable to hang a ceiling-type panel over the machine so that the sound, as it travels from the machine toward the ceiling, would hit the ceiling panel. The noise-source side of the ceiling should be treated with the cotton panels as well. This can often be left a few inches or a few feet above the top of the walls, which will allow the heat to escape on all sides.

      Please let me know if you have any questions. Thanks,
      Ted

  16. Reuben Boylan

    Hey Ted, read through a lot of your comments and analogies and found them very helpful. However I’m still rather flustered at what to do with the situation I have. The deal is that I have a practice room for my rock band on the second level of a semi detached house. The practice room is at the opposite end of my house in relation to theirs and has two concrete walls leading two the outside and two hollow walls leading to the hallway and then onto the separating wall between our houses. The thing is I want to find some way of reducing but not eliminating the sound coming out of that room into their house (they are actually quite understanding about the noise, but still, its very loud and I really want to get the decibel level down a bit!). I’m also on a budget, so the cheaper I can manage this the better! looking forward to hearing what advice you have to offer! :)

    • Ted W

      Hey Reuben,

      Thanks for the comment. Unfortunately I will need some more information to start to help you. I don’t have a clear enough understanding of the house/construction/layout. These are some questions to help me understand the space better:

      1. Are you playing full-volume guitars and drums in this space?
      2. What’s under the upper level practice room?
      3. What type of door separates this room from the hallway?
      4. What type of HVAC system do you have in this space and do the ducts lead out of the ceiling or the floor?
      5. What type of lights do you have in this space?

      Regarding being on a budget, the lowest cost way to start soundproofing the walls (which may only be part of the issue) would be to pull the trim and add two or three layers of sheetrock to your existing wall. I would also suggest sealing the gap between the door jamb and the rough opening and sealing the door to be as air tight as possible. I would also screw and/or glue a few layers of sheetrock to the back side of the door to make it heavier and add more mass. We have quite a few different types of products to increase the STC rating of not only the walls and ceilings for this space, but also for the floor and door itself.

      It is important to note that if you are rocking out at 120 dB in this room, you are more likely to introduce a physical vibration into the structure and that you may have sound going up and over the wall as well as down, through the floor, and under the wall. It is very important to note that if you have a kick drum and/or a bass guitar in the space, that these frequencies (50 Hz as an example) are likely the most problematic or bothersome due to the the fact that they could be a 22.5′ long wavelenth.

      Sorry I don’t have a better answer or set of answers for you, but unfortunately there are too many variables at this point.

      Please let me know if you have more questions. Thanks,
      Ted

      • Reuben Boylan

        Thanks Ted, after doing a bit more reading from other sources, Sheetrock was going to be my first plan of action!. What do you mean by “pulling the trim”, do you mean i should take off the skirting board?

        Now to answer your questions:

        A. Yes were playing an acoustic kit, with electric guitars a bass and vocals, all turned up loud enough to be heard over the drums.
        B. My kitchen is under the practice room, it’s quite a large room with a tiled floor. Also, it is on ground floor with nothing beneath it.
        C. It is a heavy wooden door with no panels, that leads into a small alcove before you get into the main body of the practice room. (we normally stuff two heavy mattresses which fit tightly into this alcove when we’re playing and it helps quite a bit!)
        D. The only venting system we have is a little vent on on the side of the wall that leads directly to the outside.
        E. As for lighting, all we have is one light on a cord coming down from the center of the ceiling.

        Hope gives you more information to work on Ted, and thank you very much for what you’ve wrote so far. It’s already helped me loads!

        • Ted W

          Hey Reuben, sorry for the delay in my response. Situations like yours can be quite difficult because of the amount of variables and options that you are going to have.

          I usually use the race car analogy. There is not one way to build a race car. Different types of racing, drivers, conditions, mechanical abilities, timelines, budget, etc are all going to influence the “best” car for you. The studio or room would be like the car, with the same number of variables and possible conditions. I don’t mean to be dodging the question at all – I just want you to know that there are a lot of ways this could be done, and this is just one of them.

          The trim is very likely the “skirting board”, the wooden piece on the bottom of the wall that covers the bottom of the drywall and the edge of the room. If you’re going to re-drywall the room, you will need to pull that off before the drywall goes in. You would then replace it when you were done.

          1. If you’re going to be up there playing drums and/or any kind of bass, those bass noises ARE going to be heard downstairs and most likely felt as well. Those types of frequencies are nearly impossible to block without a specially engineered structure – and many times they physically shake and vibrate the structure. They are just really difficult types of energy to try and deal with because of the height and width of the wavelength.
          2. I assume that your practice room is on the second floor and your kitchen is on the ground level? It would be strongly advised to treat the floor of the practice room with either a few layers of plywood or some kind of underlayment.
          3. I would use some weather stripping around the door to help make that more of an airtight situation when the door is closed. If you can imagine filling the room with water, what is the easiest path for that water to get out? That is exactly where the sound will also escape.
          4. If you want to send me a few pictures of the vent, I would be happy to have a look at it. Otherwise, I have had many people build small boxes or something similar with 3/4″ MDF board to throw over a vent or similar opening that can be easily removed and stored when not needed.

          Here is a home studio/practice room testimonial you can look at for some more inspiration.

          Let me know if you have more questions. Thanks,
          Ted

  17. kristof spruyt

    Hello Ted,
    I have a boiler that is making a lot of noise. It is placed inside a wooden cabinet with a wooden door for maintenance. There is an air slot inside the cabinet.
    I want to put some sound barrier/absorption material inside the cabinet and also cover the air slot with this material. I understand that if i use sound barrier material the noise will reflect and stay in the cabine, if there are no air slot anymore. I do not really understand why i can’t use an absorption material to lower the sound from inside the cabinet or can i? If a big part of the the sound energy will be changed in to heat energy in the absorption material, would this not lower the the sound outside the cabinet? Or am i mistaken?

    • Ted W

      Kristof,

      Good afternoon and thanks for the question. First, I would be careful covering up the air slot in the cabinet around the boiler. The machine likely needs this airflow to combust the fuel and/or to breathe and not build up as much heat.

      By putting a loud machine in a box, the sound pressure made by that machine will, in fact, build up and continue to build up and often times the resulting noise can be louder than the machine itself. Introducing the absorptive surface, in this case, would likely help to reduce the amount of sound making its way out of the vent. I would suggest trying the 1″ or 2″ Quiet Liner on the walls of the box and stepping back to try and gauge/determine the difference and go from there.

      Let me know if you have any more questions. Thanks,
      Ted

  18. Arne

    Thank you for the article. We are living in an apartment and are looking either to take the edge off of our bird’s noises, preferably would be to prevent neighbors from hearing or mostly hearing him, as well absorbing as much as possible. I’m fairly certain using both options would be best, but would small nails be able to support them? All we’re able to do here is use nails that are able to support picture frames.

    • Ted W

      Apartment situations are difficult because, as I mentioned in the article, blocking sound is done in the construction and assembly of the wall. Unless you can add a layer or two of drywall, you are not going to be able to block much more sound.

      I am unsure of what you mean by your question, “would small nails be able to support them?”, as I am not sure what them you are referring to. Small nails would do a fine job holding up some of our foam panels, but those panels are only going to absorb the echo within the room – they will not block sound.

      Thanks,
      Ted

  19. Raj

    Hi Ted –

    Great article! – I stumbled upon it today while trying to solve my own sound problem. I need to reduce the amount of sound that reaches my bedroom from the main part of my house.

    My house is set up in two “parts” seperated roughly by the front entry (about 10 feet by 10 feet). The entertaining space (open floorplan) is to one side of the entry and the sleeping space is to the other side. All of the bedrooms flow off of one very long and straight hallway that starts at the entry and ends at my room. The hallway is about 40 feet long, is 4 feet wide, and has 9 foot ceilings. The walls and ceiling are covered in 5/8 thick sheetrock and the floor is covered in 18 inch ceramic tile. There is no art or carpet in the hallway.

    From my bedroom at the far end of the hallway, I can clearly hear everything being discussed in and around the front entry and the nearby living room. I feel like all of the sound from that part of the house is funnelled into my bedroom. This is true even when my bedroom door is closed. I don’t have a solid core bedroom door. We have lots of people frequenting the house during the day and lots of conversations happening in the front entry. This can cause it to be quite “noisy” in my bedroom during the day. This would not generally be an issue, but my wife sleeps during the day (she works nights) and all of the noise causes her to not be able to sleep withouth interruptions. I’m looking for a fix that will reduce the amount of noice that reaches my bedroom so my wife can sleep when she needs to.

    I’ve read many of the posts before mine and am still a bit perplexed. I believe the problem is the long hallway, but I’d like your thoughts. Reducing the amount of conversations at the front of the house is not really an option. Please help.

    Raj

    • Ted W

      Raj,

      Thanks for the question. There are a few ways you can address this problem. The “best” is going to depend on what you want to do. You can try a low-cost, relatively easy approach first and see what that does, or you can take the necessary steps to eliminate and fix the problem.

      Begin by thinking about the problem like this – imagine that wherever people are that this area is filled with water, from floor to ceiling. That water is going to flow and fill up the hallway. Once the hallway is filled with water, how is that water going to get into the bedroom? That is where the sound leaks in.

      The low-cost, relatively easy approach would be to install a door seal kit onto the existing door that you have. This will help reduce the amount of air space that you have connecting the bedroom with the hallway. The parts would be attached to the door stop and the automatic door bottom to the bottom of the door. This would cost you roughly $200-250.

      If you want to properly fix the problem, I would suggest replacing your hollow core door with the heaviest, solid core door that you can find. Install it as you would install one of our soundproof doors would be installed. (A PDF of the soundproof door installation instructions will help, specifically page 10. We also have a video on how to install a soundproof door that may be helpful) After that is in, then install the heavy duty door seal kit onto the new, solid core door.

      Let me know if you have any more questions. Thanks,
      Ted

  20. Dale

    I am building a motorized lift for the lecturn of a pulpit for our church. It has a small actutator about 18″ long and 1 1/2″ in diameter with a built-in electric motor which does the lifting. I can easily connect the end of the actuator to the pulpit and the lecturn. However, a solid connection transmits the sound to the lecturn which acts like a loudspeaker. There is enough space to put something about 4″x4″ by 2″ at each end. I was thinking of some sort of sound absorbing block that I could machine to size. It should be able to support 20 or 30 pounds. Any suggestions would be greatly appreciated.

    In addition, I would like to wrap some sound absorbing material around the outside of the acutuator. Or perhaps, it could be covered with some material which hardens in place. There is about 1/2″ of space around the actuator.

    Thanks,

    Dale

    • Ted W

      Hi Dale,

      Thanks for the comment. This is a very unique situation. The difficulty here is that the motor and the arm NEED to be screwed into the wood simply to hold it in place. Those fasteners are going to transmit vibration due to the hard surface contact. The only way to FIX the problem and eliminate the transfer of vibration is to decouple the moving parts from the wood. I have a few ideas, but it could get a bit tricky.

      Depending on how much height you have to work with, I would suggest either our RSIC DC04X2 decouple clip or ND Neoprene Mounts. These would both allow you to attach everything together while eliminating the hard connection by adding in something to isolate the vibration.

      Thanks,
      Ted

  21. Karen

    Hi Ted, I hava a 6 month old puppy with separation anxiety who barks a lot . I rent an apartment/condo. One wall is brick and I share it with my neighbor. I am really working hard at trying to come up with solutions to deal with puppy’s anxiety but so It’s quite a process. I got this puppy while already living here. As a cute young puppy – I saw no signs of this anxiety. My neighbor is writing a book and home all the time. This is a recipe for MAJOR annoyance…that is building. Since I rent, I do not have control over constructing the wall that is between us. Any ideas to block his high pitched barking? I need some kind of solution. My lease isn’t up for 8 months. SOS !

    • Ted W

      Hey Karen,

      Sorry to hear that your puppy isn’t happy when you aren’t there. This is a really difficult situation to try to fix because of the fact that blocking sound typically means construction. Whether it is done when the walls are initially put up, or altering the assembly of the wall later on – such as your case. The only way to increase the amount of sound blocked by the wall is to modify it. Since you are not allowed to do any sort of construction, this is where the problem lies.

      There are a few “non-invasive” solutions that do not involve construction, but they will be a significant amount of money depending on the size of the wall. The first would be an acoustical quilted curtain – basically a really, really heavy curtain. The second is Coat of Silence paint, which you would need to be able to paint your apartment to apply it. Wall-mounted panels like foam or cotton will only absorb the echo within the room – those types of products will not block sound.

      Please let me know if you have any more questions. Thanks,
      Ted

  22. Shawn

    I think that these practices may work in my situation. My next door neighbor moved from the country to the city. I think he is used to dogs barking loudly at all hours of the night. I however am not. I’m a very light sleeper and have trouble falling to sleep. My bedroom window is only 5 ft from were the dog(s) like to run to and bark. My bedroom is a 10ftx10ft room with 2 windows. What would you suggest to block out as much of the noise as possible? I don’t want to have to remove walls/sheet rock, due to possibility of having to move out. Is there anything that I could hang on the walls? Would sealing the windows shut with a some type of material like wood help at all? I don’t mind losing the windows… Would putting any material in the attic above the room help? I’m open to anything that doesn’t cost too much. thanks for the blog.

    • Ted W

      Hello and thanks for your question. I assume that you have spoken to your neighbor and asked him to bring the dogs into the house at night? Also, there are city ordinances that you may want to explore and bring to his attention.

      Regarding treating your space, there are a few options that you may want to explore. If this were my situation, having seen quite a few instances of significant reduction, I would have our climate seal windows fabricated and install them on my two bedroom windows.

      These are acrylic plastic windows that snap into place with magnets – very similar to the seal on a refrigerator or freezer door. They are virtually invisible when installed. The pricing depends significantly on the size(s) of the window(s) that you have and I would be happy to provide you with a quote if you would like. I would also strongly suggest turning on a small fan to create a bit of background noise (aka white noise) to make your sleeping area a bit louder, but in a comfortable way.

      If the climate seal window inserts do not offer the reduction that you need, you may want to relocate your bedroom to the other side of the house, if possible. Further steps to reduce the sound transmission could start to get relatively involved.

      Please let me know if you have more questions. Thanks,
      Ted

  23. Lisa

    We have recently bought a Boss Solo TV Sound System which I believe has a mini subwoofer build in. The Boss is placed on the top of our TV unit (nothing is attached to the wall) and we never play TV/Boss loudly. However, next door neighbour has been logging on our door saying that she can hear the bass sound through the wall.

    Please advise us what we can do? Boss is a 12.2 x 20.8 x 3 inches single small unit, not a powerful sound system like a home cinema. We are thinking about to put a sizable sound proof panels on the wall behind TV unit which is at 2m x 1.5m (we are thinking to cover 2m x 2m of the wall – like a high bed head so panel is well cover the wall immediately behind TV/Boss, but not cover the whole wall which is a much large area) and install two corner bass traps on each side corner of room. Would this solution work?

    Many thanks in advance.

    • Ted W

      Hello and thanks for the question.

      This is a very difficult type of problem to try to fix because of the proximity of the subwoofer and because of the type of pressure these speakers produce. It is not surprising at all that you are getting complaints from a neighbor due to the bothersome low frequency noises (and vibration energy) that can physically shake the structure. Making the necessary changes to the structure would be very involved and quite likely, very expensive. I would suggest either turning the subwoofer off or way down and/or investing in some very good quality wireless headphones.

      Thanks,
      Ted

  24. Christian

    Our church auditorium has 1/8″ wood paneling. We’d like to take it down and just have painted sheetrock. Do we need to worry about more echoing in the auditorium taking down the paneling?

    Thanks!

    • Ted W

      Hey Christian,

      Thanks for the comment.

      I would assume that the reflection of the 1/8″ wood paneling and the painted sheetrock surface are VERY similar. You may notice a bit more echo once the wood paneling is removed, but it shouldn’t be a drastic increase in echo. This is, of course, dependent on the wood, if there are any gaps, cracks and especially if there is an air space behind it.

      Let me know if you have any more questions. Thanks,
      Ted

  25. Clive

    Hi there,

    I have a question regarding soundproofing.

    I have built a gym in one of the rooms in my flat, and my problem is that when i punch the boxing speedball, my neighbourg at the flat underneath me can actually hear it. The wall is actually made of 1 layer of bricks, and each brick measures 215 × 102.5 × 65 mm. So what happens is, when i use it, the noise created isn’t only noise of created by the speedball but also noise cause by the vibrations traveling down the wall and into his flat. Now when installing a speedball bracket to the wall, the screws hang within the brick wall.

    So my question is, what would be the best way to stop them from hearing the noise coming from the speedball hitting the platform, and after that, what would be the best way of stopping the vibrations traveling down the wall? Using which materials for what? (wall, floor).

    The room is about, 130 sq ft, or 12 sq meters, and has windows.

    • Ted W

      Hey Clive,

      Thanks for the question.

      If the vibration and impact energy is being transmitted into the wall and being carried down through the structure as a vibration, you are likely going to need to move the equipment. There are not any kind of isolators that I know of that would allow direct wall mounting that would reduce enough energy from the impact to make a difference downstairs.

      This could very well be a very site-specific problem that will need to take into account quite a few things. Because I am not there to have a look, there is only so much I can do to help. The first thing that comes to mind would be to build some kind of wooden, free-standing structure and put the entire contraption onto a rubber isolator or series of spring isolators. This would allow the structure to move independent of the structure and the vibration and impact energy would have a more difficult time getting to the structure.

      Sorry I don’t have a better suggestion, there are simply too many variables and limitations to your situation to be able to suggest a particular product to fix the problem.

      Thanks,
      Ted

  26. Shane

    I am doing a science project on blocking (not absorbing) sounds. I have a guitar amplifier that will be plugged into a computer to produce a sound. Do you have any suggestions of how i can cover the amplifier from all sides in the different materials i want to use and maybe some suggestions of cheap materials that are easy to apply. And im not sure if the sound comes out all sides of the amp.
    btw thanks for the easy to understand article it was very useful
    Link to the amplifier i’m not sure if it contains the size of the amp: http://www.amazon.com/Line-Spider-IV-15-Amplifier/dp/B002GYWBIM
    If you have any other advice or suggestion i would be glad to hear them.

    • Ted W

      Shane,

      Thanks for the comment. Here is what I would do:

      The first thing is that your barrier has to be air tight. I would first build a box out of plywood, put it straight over the amp, and turn it on. Take three measurements with this setup and average those. Then I would add some weather stripping to the bottom of the box and repeat the test three times. After that I would add a layer of 5/8″ sheetrock glued to the outside of the box. Make sure you keep your cuts straight and seal all of the seams. You could also build a larger box out of 3/4″ MDF board and use both covers. Build this second box so that is leaves 1-2 inches of air in between the plywood and sheetrock box.

      Three things to remember:

      1. Keep it sealed
        • Your sound barrier has to be air tight to be effective
        • A 1% air gap will leak 30% of the sound and a 5% air gap will leak 90% of the sound
      2. The heavier, the better
      3. Noise barrier, then air space, then noise barrier will always be helpful

      Good luck on the science project. I’d love to hear how it turns out.

      Thanks,
      Ted

  27. Andrew

    I’ve got a question. I live in a 4th floor apartment and there’s a Jacuzzi across the courtyard with a pump that makes a constant, very, very high frequency sound when in operation. Unfortunately the sound from it reverberates across the courtyard and is quite noticeable in my apartment. I’ve been talking to the maintenance here and trying to come up with an *easy* way to rectify the problem. I’m sure there’s some newfangled whisper quiet jacuzzi pump that would fix it, I don’t believe they’ll be replacing it anytime soon. (I’ve been down that road)

    Anyway, the other day, the maintenance guy allowed me to see the Jacuzzi jump itself (it’s behind a locked gate). It turns out there’s an outlet pvc pipe coming from the pump, and this outlet pipe is responsible for blowing a bunch of air out that is sucked in by the pump during its operation. Alas, out of this pipe, along with a powerful stream of air came a very powerful high frequency whine.

    I considered this good news, because the source of this noise is isolated and relatively small in size — a 4-5 inch diameter, downward pointing outlet pipe made of pvc. Because the source is isolated in this way, it seems to me it should be fairly straightforward to build an aparatus to dampen the sound. Indeed, I was able to cup my hands a few inches underneath the pipe (again, the opening of this pipe points downward, toward the ground), while being careful of course not to block the airflow, and the noise decreased *greatly*. So much so that I doubt I would be able to hear it from my apartment.

    In lieu of hiring someone to stand there with their hands cupped a few inches under a pvc pipe,
    this leads me to my main question –
    Do you have any suggestions on what would be an effective apparatus for dampening this sound? Such an apparatus should have a few characteristics:
    It mustn’t block airflow from the pipe.
    It should be resistant to the elements. This is southern california, so we don’t get snow and it hardly ever freezes, but it does rain occasionally.
    It should be fairly simple and fairly inexpensive.

    Also see this image, I draw out what I’m talking about. Hopefully it clarifies things:
    http://imgur.com/DpO1K3T

    Basically, I’m proposing an aparatus that sits underneath the pipe and dampens the sound, similar to how my cupped hands do this. This is just an idea, though… I was hoping I could get some advice from someone that has experience in the area of sound reduction.

    Thanks much!

    • Andrew

      Just to follow up, would a 4 or 5 inch duct silencer / duct muffler be appropriate for this?

      Thanks.

    • Ted W

      Is there any chance you could take and share a photograph of this, please? A picture of the situation would be a great help to me. I do, however, have two ideas.

      The first would be to put 6-8″ of sand on the ground below the pipe. Even building a box out of plywood and filling it with sand would likely reduce the amount of sound reflecting off of the ground and filling the court yard.

      The other idea would be to use an exterior grade plywood and build a three-sided, free-standing structure around the pipe. I would probably start by building it using three walls with the potential to add a roof section later, if needed. This structure could be built around the exhaust so that the sound and air that escape are contained by the structure. This could EASILY be lined with an exterior rated absorptive surface if the plywood does not offer enough reduction. Here are a few images I quickly threw together to illustrate the idea: (It was a lot faster for me to make this pipe using flat-surfaces rather than a rounded pipe)

  28. Ronald Moberg

    I recently had a sprinkler system installed with a water pump. The water pump is so loud that it is waking us up when it starts up at 3 am. What sound proofing or sound absorbing material should I use. The pump is located outside.

    • Ted W

      Most people that have irrigation pumps like this will build a plywood “dog house” around them simply for aesthetic reasons. This enclosure can be built with commonly and regionally sourced building materials, like plywood. I have even seen enclosures where the cement-board (like that used for bathtub surrounds) is used to line the inside of the walls simply to make them heavier.

      If you build something like this and you still have a problem, I would be happy to help you find something that we could supply that would reduce the sound further. Since you will need some kind of structure/enclosure anyway, I would suggest starting with that and then reassessing the situation.

  29. Hermione

    What very interesting and informative information. I would like advice on further sound insulation in my ground floor flat. I have had a suspended and isolated ceiling installed with material laid in the space between old ceiling and new one. This has sorted noise from tv, talking, music and has had a significant effect on heat retention. However impact noise, footfall is still a problem. The flat is rented out and as I have a good relationship with the owners I am wondering what could be done from upstairs, whether it would be necessary to lift existing floor and insulate between joists or if just putting some sort of underlay down would work. I have access to the stairs in an outside cupboard, would it be worth removing the plasterboard and filling the spaces between the treads, if so with what? Many thanks, Hermione

    • Ted W

      Hermione,

      Thanks for the question. The only product that I would install in a situation like this would be the 3/8″ thick (9.5mm) Acoustik.

      This is a rubber-based underlayment that would need to go down onto the floor upstairs and then covered with a finish floor. This would help soften the footfall before that energy got into the structure. After that energy shakes the structure, everything that touches it shakes as well – which is why filling a cavity (stud-wall, air space in a ceiling, etc) with insulation may help to stop a BIT of airborne sound but doesn’t reduce impact energy at all.

      Let me know if that would work for you or if you have any more questions. Thanks,
      Ted

  30. chetan

    Hey,
    I have a unique problem. Our office has a very quiet area. There is a large multifunction printer that was recently installed in the quiet area. People are annoyed and we want to reduce the noise levels in that area. The printer is enclosed by walls on two sides (behind and right) but is open in the front obviously and on the left.
    Short of putting a smaller printer in that area is there something that i can stick to the walls to reduce the noise. I can install another wall on the left but have to leave the front open for people to walk in grab their print jobs. The space is not big enough to put the unit in a enclosure.

    Sound blocking will probably direct all the sound to come out from the front side which is open and sound absorption will only absorb echoes
    Is there another solution in this case?

    • Ted W

      Chetan,

      Thanks for the question.

      There are a few ways to treat something like this. I would probably start by putting a panel (or series of panels) onto the walls around and behind the machine. You can often get a decent amount of reduction simply by removing the reflective surfaces behind the noise source. This is also the least costly and least intrusive first step. I would probably suggest waiting to build the new wall until you’ve installed the panels and assessed the reduction.

      If you happen to have a few photos of the space, it may help me (and others) visualize the problem.

      Thanks,
      Ted

  31. Ruth crawford

    Love the info on this site. I have a great room with high ceilings, lots of windows with no curtains, granite counters, and tile floors. It echos a lot. Would it help if I put sound absorbing foam of some sort on top of the kitchen cabinets near the ceiling that would be out of sight? There is nowhere to put panels on the walls or the ceiling. What would you recommend?

    • Ted W

      Ruth,

      Thanks for the question, glad to hear you are enjoying the info here.

      I have had a few people put product on the top, unseen side of kitchen cabinetry and it will absolutely absorb some of the sound in the room. Unfortunately, these areas are usually relatively large rooms which require more square footage of panels than will fit on the tops of the cabinets. If there are no wall/ceiling spaces available, and floor treatments are not an option for cleaning reasons, it causes a problem. In order to absorb sound, you need to cover a reflective surface with an absorptive surface.

      So, absorptive panels will work, but depending on the amount of space you have to put them in “hidden” places, you may not hear much of a difference.

  32. Diane

    Ted,
    We are upgrading our older home built in the fifties. We have a narrow hallway with three bedrooms and one bathroom door coming off the hallway. It is the standard “ranch” house design. I recently replaced the hallow doors with solid doors to help cut down on the sound between rooms. When the new doors were installed the contractor left a gap between the rough opening and the door of approximately 1/2 inch all the way around. He then filled the gap with foam all the way around. I could swear the noise problem is worse instead of better with the solid doors! What can we do? My contractor says if he pulls out the new doors and closes the rough opening down to a quarter inch with wood, the sound problem will be the same. He says the foam is a better buffer than wood. Any ideas?

    • Ted W

      Your question about the installation of the door is a good one. In your situation, though, I don’t know if it is exactly the correct question to be asking.

      As I have mentioned in this article, as well as quite a few other comments, sound always uses the path of least resistance first – a lot like water. Even if you followed the installation instructions from our Studio 3D soundproof doors and used the backer-rod and acoustical sealant to eliminate sound transmission between the door jamb and the rough opening, without adding some kind of gasket/sealing system to the door, you are not going to eliminate the biggest path of least resistance which is the air gap(s) under and around your door. If you can fill one of these rooms with water, how is that water going to get from the room into the hallway? This is also where the sound will get out.

      So, sealing the jamb-to-rough opening joint/gap will absolutely be beneficial, but in this case, an adjustable door seal kit and/or some simple weather-stripping to make the door more of an air-tight assembly when it is closed is likely a more important idea to consider.

      Thanks,
      Ted

  33. Mark

    Hi
    Thanks for the great info and clear explanations.
    Very generous of an expert like you to help us beginners.
    I wonder if you could give me some advice before i waste my money on the wrong solution.
    I need to make a silencing box for a petrol generator, like the design on this page:
    http://www.acousticsblog.com/2012/soundproofing-small-loud-widgets/

    That design uses ” mass loaded vinyl composite foam”.
    Do you think I could use this “Sound Deadening Underlay” as a satisfactory (and cheap) replacement:
    http://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&item=130899180681&ssPageName=ADME:X:AAQ:AU:1123

    Would it be fire proof enough for that purpose, and have the correct sound proofing properties.
    Thanks heaps for any advice you can give,
    Mark

    • Ted W

      Hey Mark,

      Thanks for the question. I tried to go to the link for the “sound deadening underlay” but the item was no longer for sale, so I cannot answer the question about the product being a satisfactory and cheap replacement. Nor can I answer “whether or not it would be fire proof enough”…

      Basically, when you create an enclosure, there are a few basic ideas to keep in mind. The walls of your enclosure need to have a decent amount of mass and density – they need to be heavy. The heavier something is, the more sound it will block. Whether you use MDF board, sheetrock, plywood, cement – the heavier the better. The second is that if you make any kind of air intake or exhaust, you will need to introduce two 90° bends so that you can’t look straight into or out of the enclosure. I would absolutely line the inside of the enclosure with some kind of soft, reflective surfaces as well so that you do not create an echo chamber for the noisy machine.

      Please let me know if you have any more questions. Thanks,
      Ted

  34. Mark

    Hi Ted,

    I live in a historical (read old) interior row house where the walls are all brick, block and plaster. The wall separating the neighbor’s guest bedroom and our master bedroom is very poor at blocking sound. We hear the neighbor’s child crying at night, which is upsetting. We are getting estimates from builders, but it’s clear they don’t have a lot of experience. We want to be sure that we can have them install a good solution. They all want to build out the wall 11 x 11 and add soundproof sheetrock. What else do you recommend ? accoustical glue, special clips. We have two outlets, should they be wrapped in rubber? Thanks, Mark

    • Ted W

      Hey Mark,

      Thanks for the question. I am happy to offer some suggestions, but because I am not there to look at the wall and experience the situation, I am going to have to make some assumptions that may or may not be correct. So, if anything comes to mind based on my reply below, please feel free to let me know any additional information or details about the wall.

      Typically speaking, brick and block do a pretty good job at blocking sound. They are constructed well, have a lot of mass (density/weight), and are relatively airtight. All good things when it comes to soundproofing. At the same time, every old building will settle and the walls, floors, and/or ceilings could separate from each other slightly – causing small gaps/cracks in different locations. The sound on one side of the wall is ALWAYS going to use this path of least resistance first, so sealing these gaps/cracks is going to be important. I would use a non-hardening acoustical sealant for those locations. A good rule of thumb is that if you think you might need sealant, you need sealant.

      As far as the new wall goes, the studs and 5/8″ sheetrock alone are very likely going to offer some reduction in the sounds that you are reporting. I would absolutely fill the stud cavities with a standard insulation, like fiberglass or cotton. The framing should be at least a half inch away from the existing wall and any/all gaps/cracks should be filled with sealant. All outlets in that wall should be backed with a putty pad. A step up from a standard wall (studs and 5/8″ sheetrock) would be to simply double-up the sheetrock, essentially making the wall heavier.

      A step up from the studs and double-sheetrock assembly would be to proceed with one of the following: Install a product called Green Glue between the two pieces of 5/8″ sheetrock or Install a layer of SoundBreak XP or some other acoustically enhanced drywayll onto the studs.

      Blocking yet more sound, you could add the RSIC-1 clips to the face of the studs, then add the sheetrock. Again, two layers would block more sound than one.

      Dollars spent based on performance, my most preferred assembly would be to use the RSIC-1 clips, the standard hat channel (which is always used with the clips), a layer of 5/8″ sheetrock, a layer of Green Glue, and a second layer of 5/8″ sheetrock. In my opinion, this is an extremely effective assembly, but may be overkill for your situation.

      Let me know if you need more information or have any other questions. Thanks,
      Ted

  35. Shawn N. Onthin

    I want to start a weekly or monthly gathering known as Penthouse sessions. I am a DJ and will be playing music from relatively loud speakers. I live in a penthouse that is about 2,250 square feet. Sound is very good within the rooms and never get complaints.

    Although I want this gathering/social to be in the living room. I only have one neighbor to worry about. The ones across the hall wont hear a thing.

    That being said, what do you recommend to the one neighbor that is next to me rather than across the hall. Without anything I get pretty loud and nothing happens. But I would have for the social to get disrupted with a complaint.

    Maybe something simple under the door will do or ? I don’t know.

    Look forward to hearing from you!

    • Shawn N. Onthin

      its mainly the bass that i want to keep from disturbing the neighbors ! the living room is an open layout very spacious and open no walls in between and barely any furniture. the rooms are the only areas with walls and doors.

    • Ted W

      Hey Shawn,

      Great questions! I would like to begin by mentioning that the potential situation that you are presenting is going to be an uphill battle. In order to approach a situation like this properly, it will require a fair amount of construction and modification to the wall and possibly the floors and ceilings as well.

      There is a direct relationship to the type of noise (frequency) and the ease in which the frequency gets through whatever you put in front of it. The lower the frequency (bass), the easier the sound gets through the barrier. It’s a constant in physics which has everything to do with the height and length of the wave of energy. Low, bass frequencies almost always introduce a physical vibration into the walls, ceilings, and floor. Reducing the amount of sound getting out of your space will, unfortunately, not be a cheap/easy venture – like sticking something under your door.

      In complete honesty, it is going to be more cost effective for you to send your neighbor to a nice hotel once a month (getting them out of the building while your social gatherings are taking place) than it will be to undertake the project to try and block the sound from bothering them. I understand that you are not likely looking for complete silence on the other side of the wall – you are likely just looking to start to reduce the problem. I completely understand, I have approached this question a few hundred times in my ten years in the industry. This is typically why “bass-heavy DJ style gatherings” take place after hours in warehouse districts where residents are far away while the events are taking place. If no one is around to hear (and complain), then there isn’t a problem.

      So, on to answering your question. The steps necessary to start to reduce the problem would be as follows:

      1. Remove the floor and install a layer of 5/8″ Acoustik Underlayment. Then re-install the floor on top of this underlayment.
      2. You will likely want to remove the drywall from the walls in question and fill the stud cavity with insulation.
      3. Install RSIC-1 Sound Isolation Clips
      4. Add a 5/8″ layer of standard sheetrock.
      5. On top of that sheetrock, apply a damping compound called Green Glue
      6. Add another layer of 5/8″ sheetrock

      Depending on the nature and severity of the problem, you may also need to treat the ceiling so that the vibration energy introduced by the speakers is absorbed (turned into heat by the physical vibration of the new wall/ceiling assembly) instead of being transferred from the drywall to the studs or joists. This is not the only way to approach the situation – there are similar options out there that could likely offer some reduction – but no option will be as easy as putting up a few foam panels and calling it good. Reducing the problem at all will require some drywall work/construction.

      Another option is to start with a small gathering and increase both the size of the gathering and the volume until you get a complaint. Then scale back slightly. Or just invite all of your neighbors over.

      I am not intentionally trying to take the wind out of your sails, but it is important for you to understand the nature of the problem and the potential extremity of the undertaking to offer some benefit for this type of acoustical situation.

      Please let me know if you have any more questions or if you would like to discuss the situation some more.

      Thanks,
      Ted

  36. James

    I recently moved into a condo(renting) and in my bedroom I share a common wall with some very chatty neighbors. I can’t do any heavy construction like adding a layer of dry wall. I need some cheap alternatives or suggestions as to what I could do besides my grand idea of using Heavy foam(or work out mats) to create a 1-2 foot thick artificial wall to try to drown them out.

    I have a but space in my bedroom, Can you help?

    • Ted W

      Hey James,

      Thanks for the question. Unfortunately the right answer to your question is not the one you are looking for. Blocking sound is something that is done in the assembly of the wall – not something that you can easily and cheaply put onto the wall.

      Foam will not block ANY sound. Foam, panels, and the like will not reduce any of the sound and could potentially make the problem more noticeable to your ear because the point of a wall panel is to reduce the echo and ambient sound in the room in which it is installed.

      The lowest cost and least intrusive way to reduce sound transmission through your wall would be to add a layer of Green Glue and a second layer of 5/8″ sheetrock.

      Let me know if you have any more questions. Thanks,
      Ted

  37. Tracy

    Hi Ted,

    I am very appreciate of your blog on acoustics. I live overseas in a developing country and we are in the middle of a 1 1/2 story house construction. The home is made of bricks and plastered on the inside. The roof is metal. Because we live in a tropical country we do not need insulation like we do in the states. Because we live at 7200 ft above sea level it doesn’t get too uncomfortably warm outside, but with a metal roof, the upstairs can get quite warm inside. Our second floor has metal trusses, with wood trim to secure the waterproof flooring. Our inside walls are made from eco-board (recycled tetrapack containers) that are 10mm thick.

    I have two issues I am dealing with.

    1. We need to keep insulate ourselves from the heat of a metal roof
    2. We want to minimize the sound that comes in and out of the master bedroom. Our master bedroom is adjacent to our tv room.

    We do not have access to sound proofing materials where we live, but we do have styrofoam and fiberglass insulation. Will these materials help? If so, are there specific ways to install these materials to maximize the sound/heat reduction?

    If there are any other basic materials we could use instead, we are open for suggestions.

    Thank you so much.

    • Tracy

      Ted,

      I should also add that we have a small “crawl space” attic since it is a 1 1/2 story home. Our ceilings are also made from the 10mm tetraboard (like the walls). The wall between the Master bedroom and tv room only goes up to the ceiling, but does not continue up in to the crawl space.

      We are using a PVC material that looks like a hardwood floor (beautiful stuff) that is glued onto the waterproof plywood.

      I don’t necessarily need to make our MB 100% soundproof, but it would be nice to minimize the sounds a happily, healthy marriage makes (smiles).

    • Ted W

      Tracy,

      Hello and thanks for the questions. This is a bit of a new situation for me to approach and I may or may not be able to help. But, I am going to have to ask you to think about this a bit differently than I think you might be, but that’s my assumption based on your comments.

      The thermal issues and the sound blocking issue are going to need to be considered as two completely different situations. Sound is blocked by (first) eliminating any and all common air gaps/spaces that connect two rooms and (second) by increasing the amount of mass/density between the two spaces. Heavier is better. Things that do a good job at thermal insulation do not block sound – and generally speaking, things that do a decent job at blocking sound are not used for thermal insulation.

      Thermal protection is done with things that are soft, light, and fluffy – like standard wall insulation. These types of products are mostly air, which is why they offer the thermal protection they are used for. Considering they are mostly air, and sound travels through air – sound goes right through insulation. MANY people think that insulation will block/stop sound, but that is just not the case. I’m not an expert in thermodynamics, but I would insulate the ceiling with a standard, everyday fiberglass and finish it with some kind of solid surface like the rest of the room.

      The sound transmission issue is going to depend on a few different things and I may not have a solid answer/approach for you yet because of the amount of variables. I will start by admitting that I have almost NO education or familiarity with the building/structure that you are likely in, so I am going to make a lot of assumptions that have a slim probability at accuracy to the actual situation. If you have any heating/cooling ducts that lead from the bedroom into the air space that is shared with the TV room, that is the first place to start. If there is an air space that connects the two rooms, that is the easiest path of least resistance for the sound to get from one room to the next. The next place to look/consider is the door. The air space under and around the door can be a significant area that the sound uses to get out of the room.

      If the sound is, in fact, going through the wall, the best way to proceed is to use the heaviest building material that you have access to and simply make the wall separating the two rooms heavier. I’m not sure where you are or what building materials are in your area, but the heavier the better. I would suggest, however, to throw out all of the assumptions you have about sound and how it works and listen VERY critically to the problem before buying anything. Put a constant noise source, like a radio, in one room and go to the other (preferably when it’s very quiet, the middle of the night can be a good option) and listen. Listen to the ducts, outlets, gaps/cracks between walls and floors or ceiling, and the gaps around the door. Find the weakest link in the room and start there.

      Hopefully this helps. Let me know if you have more questions or need more information.

      Thanks,
      Ted

  38. Silvara Junus

    Dear Ted,

    Thanks for your great acoustic and sound articles! They are very informative and I enjoy reading them. Currently, I am assigned to reduce the echo in a multipurpose hall. It’s a room of rectangular shape, basically an empty hall with hard surface all over. Hall dimension is 200 ft. x 80 ft. x 24 ft. It echoes like crazy and a nightmare for any soundman. We can’t put carpet on the floor since the hall is also used as a badminton court. By the way, it is a concrete floor. Due to budget constraint, my plan is to use used egg trays (egg cartons not the egg crate foam) to cover 3 sides of the wall in hope that the conical shape of egg trays may deflect the sound wave thus reducing the echo. I am not sure whether this will work though. Can you give any opinion on this method? Thank you so much.

    • Ted W

      Silvara,

      Thanks so much, I am glad to hear you enjoy my articles. I am sorry to say that I am not at all familiar with the “egg trays” that you are referencing, but logic tells me that these are probably some kind of hard, maybe plastic trays that are used to transport eggs from space to space. They are probably formed to the shape of the egg and made out of a hard, stable material. If my assumptions are correct, and if these trays are hard, formed sections of something, the idea probably isn’t going to offer the reduction that you are looking for.

      The SHAPE of a hard surfaces only determines the angles that the sound will reflect off of them. Think of it this way… take a bunch of your trays and put them on the wall. Stand a few feet away and throw a ping-pong or rubber ball at them. The ball will bounce off the tray with quite a bit of energy. Probably the same amount of energy it would if it were bouncing off the drywall. Now, instead of your trays, put a sleeping bag or some other soft blanket on the wall instead. The soft, light, fluffy nature of the fabric-like material will absorb the energy of the ball. The same works with acoustics.

      So, I would strongly suggest exploring some type of cost-effective acoustical panel. Something that is at least 1″ thick, and that has an NRC value. That type of approach is going to serve the space SIGNIFICANTLY better than a hard, formed piece of plastic, wood, or hard paper.

      Check out this article that discusses acoustics in multipurpose rooms. It goes over a little more on the hows and whys as well as having a testimonial at the end.

      Hopefully this helps you out. Let me know if you have any more questions. Thanks,
      Ted

  39. Mary Heise

    Hi Ted, To begin with thanks for this webpage. My problem is with the kitchen, there is no sound absorption in it. It is 17 x 15 with 9ft ceilings, painted wood floors and one wall is nothing but wooden doors, leading to the upstairs, downstairs, a bathroom and a pantry. There are also 2 doors on one wall and one on another. There are also 4 windows in the room. This leaves very little wall space. We have wainscotting going up the wall for 5 1/2 feet. The room echoes with all the conversations when having more than 4 people speaking. I would like to stay away from ceiling tiles made for this purpose. My question is how many wall panels would be needed and how big do they have to be to help with the sound absorption. I found information on how to make them. I am just not sure if i have enough wall space to place the adequate amount of panels to fix the problem. My husband would like to ad beams to ceiling in hopes that those would help. I have enough wall space for possibly 5 – 30x20inch panels. Would this be enough? I would like to make them look more like art pieces than the standard panels. Please help ! Any info would be appreciated! Thanks, Mary

    • Ted W

      Mary,
      Thanks for the comment. As I have mentioned before, treating residential spaces can be extremely challenging because in order to absorb the sound, you HAVE to cover up some of the reflective surfaces with an absorptive surface. Which, of course, means changing the way the room looks. I don’t have an invisible way to absorb sound. I wish I did! :D

      Unfortunately, installing 5 panels measuring 30″ x 20″ is not likely enough to make a noticeable difference in the space. Considering the cubic volume of the room and the surfaces that make up the space, I would suggest starting with forty-five or fifty square feet of panels. The panels mentioned above would cover approximately twenty-one square feet of this, so about half. There is no way that twenty-one square feet would make the problem worse, but it may or may not introduce a noticeable reduction to the room.

      Hopefully this helps. Thanks,
      Ted

  40. Ryan N.

    I have a problem with my upstairs neighbor when they use their washer/dryer. It literally sounds like its coming from my unit. Is their anything I can do to minimize this? I’m sure they would be okay with me installing something underneath their washer/dryer to help. Preferably something that can be removed later.

    Thanks!

    • Ted W

      Ryan,

      Thanks for the comment. There is a product that I can suggest for this, but I must state that blocking sound is something that needs to be done fairly specifically to be done at all. This basically means that you could potentially get a product on the floor of their laundry room and still have a problem. Sound travels via the path of least resistance, so if there is an easier path for the sound to use than coming straight through the floor (like a duct, pipe chase, etc) you may or may not get enough reduction to notice a difference. With that said, it’s likely that the product below will help, but I just wanted you to know that it’s always a possibility.

      I would start with a layer of Quiet Floor NP, which is a rubber-based roll of recycled car tires. This will introduce a fair amount of mass into the assembly as well as introducing a slight vibration dampener/shock absorber between the machines and the floor.

      If you would like a sample or quote for a sheet or two, feel free to let me know. Thanks,
      Ted

  41. Luba

    Dear Ted thank you so much for very valuable info!
    There are a lot of people who will apprecciate an answer on my question.
    I live in a small condo on the second floor and want to buy a portable washer/dryer combo and place it in the closet w-30,d-38,h-90″. The combo is 24″ wide. The problem is for frontloaders washers that they vibrate more than top loaders.
    What should I place on the floor under machine to reduce vibration to my neighbor downstairs? Should I place an absorptive material on the walls?
    I will paitiently wait for your response before buying machine.
    Sincerely, Luba@

    • Ted W

      Luba,

      Thanks for the comment. There are a few different ways to approach a situation like this. In order to get you a more concrete answer to your question, I am going to need to get an idea of the overall weight of the machine(s) at their heaviest.

      The easiest and lowest-performing approach would be to put a layer of Acoustik on the floor directly below the machines. This is a roll of recycled rubber – the smallest size available is a 4′ × 5′ piece.

      You could also install one of the two rubber vibration isolators: Super W Pads or ND mounts

      I have also had previous customers install simple spring isolators under a piece of plywood to essentially make a new, floating floor. This will out-perform any of the rubber-mount approaches: IMF Spring Mounts or SLF or SLFH Mounts

      Let me know if you have any more questions. Thanks,
      Ted

  42. Roscoe

    Hello,

    I am trying to sound abate my Honda civic before installing an after market audio system. With which materials should I treat the doors, especially the two front that have the speakers? As you might know, there are two layers of metal and holes in the inner sheet metal. I have planned to use dynamat and a MLV. Is there a critical role for foam, especially in order to maximize the dynamic range of the mid-woofer speakers in the two front doors?

    Thanks! :-)

    • Ted W

      Roscoe,

      Thanks for the comment. I had to defer to my co-worker, Mike, on this one as he is a much better resource for a situation like this. Mike owned a very high end car audio company for quite a few years. This is what he has to say:

      “Treating your car for the audio system can make all the difference in the sound quality and overall enjoyment of your listening experience.

      I would recommend using our VMAX product on all your door skins, covering the entire area behind the door panel. You will want to cover all the open holes in the door kin so that you separate the front of the speaker from the rear of the speaker as best as possible. You will simply use a razor blade to cut small openings for wires, latches, etc. This sealed design will allow for a better low frequency response from your speakers and a louder response with less distortion. The VMAX material will reduce all the vibrations in the metal door structure and create the separation needed.

      To enhance and control the back wave of the speaker, you can glue a small piece of our Sound Silencer to the inner door skin directly behind the speaker, if space is allowed. Using typical foam in the door cavity will create problems due to water and moisture that will enter your door cavity. The Sound Silencer will not be affected by these conditions.”

      Let me know if you have any more questions. Thanks,
      Ted (and Mike)

  43. Jerome

    Hello Ted,
    Great job simplifying this stuff.
    Imagine a portable generator or an irrigation pump running. It makes quite some noise. Is there any sort of material it could sit on and be less noisy? And by how much would the noise drop. Please, keep in mind mobility and portability.
    Regards.

    • Ted W

      Jerome,

      Thanks for the comment. You could potentially put the machine on an acoustical panel but it may or may not make much of a reduction in the sound that you’re hearing. It would likely reduce the sound that is coming out of the bottom of the machine, bouncing off a hard surface and up toward your ear – but it would not be introducing a direct line-of-sight noise barrier that would offer the most reduction. I would safely say that the most you could get out of a “pad” of some sort would be a 3-4 dBa reduction simply by taking out the reflections from under the machine.

      I hope that helps! Let me know if you have any more questions. Thanks,
      Ted

  44. Melanie H

    Hi Ted – thanks for a brilliant article which explains ‘sound proofing’ so well. I am just about to start building a new Chicken Coop. Whilst we don’t have a cockeral, the girls can be pretty vocal early in the mornings at sunrise, so whilst we are building the new coop we thought we’d take the opportunity to add some sound proofing. I guess I would need to be concentrating on sound blocking to prevent the sound reaching the neighbours. The coop will only be 4ft by 6ft so only a small space. What materials would you suggest? We were going to use rockwool but believe it is a breeding ground for red mite, so that’s out of the question. Another key challenge is ventilation. I read on one of your earlier replies that a 1% gap will leak 30% of the sound, however the chooks need ventilation – any tips? Thanks if you can help

    • Ted W

      Melanie,

      Thanks for the comment. Unfortunately I am not sure how to suggest you proceed. This is a very unique situation. You will need to build some kind of room or enclosure around the coop and build a baffled duct system to push and exhaust air into and out of the enclosure. Other than that, I don’t know what to suggest. Sorry.

      Let me know if you have any more questions. Thanks,
      Ted

    • geovanny santamaria

      Hi ted.
      I am a music educator and I liked your illustrations as to how to block or absorb sound. I am currently looking to equip my basement with material for sound blocking purposes. My goal is to have enough material so I can totally seal the room and not let the sound out since a rock band will be using the basement for rehearsals. In my mind, I thought that covering all the walls and ceiling with foam would do the job. How true is that? if foam does not block the sound, do you have a suggestion for my particular case? what is a good/inexpensive option?

      • Ted W

        I’m sorry to say that my answers to your questions are not going to be what you’re hoping to hear. Without a doubt, if you have a band practicing in your basement, you will hear and probably feel the bass upstairs. As I noted in the article, foam DOES NOT block sound. Foam will not reduce the sound that makes its way to the rest of the house.

        There is not a cheap, easy, effective way to block the sound of a band from getting upstairs. Doing this would involve significant modifications to the floor/ceiling assembly, HVAC for the room and the lighting.

  45. Gabriela

    Hello Ted,

    I am designing a ‘prayer room’ for a church. It is approx. 14′*14′ room in an old New England wood house. The idea is that people praying in the room could raise their voice or play worship music maintaining privacy and not disrupting anyone outside.

    Until I read your article, I thought that I needed an ‘absorbing’ material – thinking: if the sound is ‘absorbed’, then it doesn’t travel through the walls. But now that I read your article I am confused. I understand that ‘soundproofing’ makes the sound stay in the room and not travel through the wall. However, isn’t the same as ‘absorbing it’ – the sound stays in the absorbing material?

    I know you might be thinking, “ahh, didn’t I already explain!”, but I really would appreciate your guidance.
    Thank you!

    • Ted W

      Gabriella,

      Thanks for the comment. Rather than re-writing the article, do you have any specific questions I could answer for you?

      Panels that absorb sound within a room do not block sound, and typically, vice versa. If you were trying to fix a leaky fish tank that you bought off of Craigslist, you wouldn’t line the tank with sponges and expect the leak to not leak. Absorbers are light, soft, fluffy and porous materials that ABSORB sound. If you were to pour water onto a sponge, it would go right through it. Sound barriers are essentially the opposite – hard, air-tight, dense and heavy. If you fixed that fish tank with new glass, the water would not pass through it. Absorbing sound and blocking sound are two very different ways to approach acoustics.

      Without knowing more about the (a) construction of the walls made to build this room, (b) the heating and cooling system for the space, and (c) the door that is used to gain entry to the room, I don’t have much to go by to start to make recommendations.

      I would assume that you could benefit from adding green glue and an additional layer of 5/8″ drywall to the walls, replacing the door with a solid-core wood door – making sure to install the door jamb into the rough opening properly (see our sound-rated door installation instructions for that), addressing any supply and return ducts with an acoustically absorbent liner as well as making two 90° bends in each, and potentially treating the windows.

      Let me know what specific questions you have so that I can address them specifically to hopefully add some clarity for you.

      Thanks,
      Ted

  46. Allyssa D

    Hi!

    I am looking to add sound proofing materials to the conference room in my office building. It’s an hold historic building with asbestos in the walls, so we can’t technically put holes in it, and although my bosses and I agree that putting a few nails in the ceiling shouldn’t hurt anyone, it isn’t our decision. Our conference room echoes so badly that we need to do something. I was looking at the foam that looks like egg cartons? I’m not sure. The ceiling is covered in pipes, so we were thinking that we could hang something from them just to put up some obstacles to get in the way.

    Honestly, I have no idea what I need to do, so I hope you can help!

    • Ted W

      Alyssa,

      Thanks for the questions. If you could send me the dimensions of the room as well as a digital picture or two, I would be happy to do what I can to help.

      There are methods of attachment that would allow you to get a few of our panels in place without using glue OR nails – they could be removed as if they were never there – so have hope! And, I would be happy to help. All I need is a rough idea of the dimensions of the room (height, width, and depth) and a few digital pictures. This would allow me to build a quick digital acoustical model of the space and estimate the number of panels or square footage needed to take the edge off. If you send me a message with your name and address I could get a few different types of panels into your hands for review.

      I look forward to hearing back from you. Thanks,
      Ted

  47. wayne

    Downstairs townhome with window to loud carport parties, and indoor upstairs stomping loose floors, kitchen cookn and loud relatives. snoring next door thru wall.lowbudget.help

    Low budget help

    • Ted W

      Wayne,

      Thanks for the comment. Unfortunately I don’t have much to recommend to you – this sounds like a relatively extreme problem that will require a fair amount of construction to begin to reduce the noise that is bothering you. Also, I don’t have any information about the structure that you are dealing with. I could throw a few things out there, but they would be simply assumptions. I’m sorry, I would need more information to start to offer recommendations.

      I can tell you that if you have people upstairs stomping and introducing enough energy into the structure to shake/move/vibrate the structure, there is unfortunately not a lot that can be done. Acoustical treatment can only reduce things to a point – engineering and physics also need to be considered.

      Good luck and let me know if you have any more questions. Thanks,
      Ted

  48. Raz Shankar

    Thanks for a clear explanation.
    My question.
    If I build my own hifi rack I want to absorb vibrational (sound and environmental) energy.
    What materials are best at that? Bearing in mind that it has to carry load, sometimes of many kilos.
    I ask because one can find many materials used including wood, glass, metals, slate, carbon fibre, composites etc, either on their own or in combinations with each other (constrained layer damping).
    I am a bit confused by all of this.
    Your thoughts would be very welcome.

    • Ted W

      Hey Raz,

      I am not quite sure what you are asking, sorry. I am making an assumption that you want to stop vibration transfer from one surface to another. That is not done with acoustical panels — that is something that you accomplish with a vibration isolator. Springs are the most effective option as long as the spring is rated for the load which it needs to carry/support. A step down from that is a proper load-rated rubber isolator.

      Let me know if you have any more questions. Thanks,
      Ted

  49. Nancy

    Hi Ted,

    Enjoyed reading your article, though I’m still not 100% sure which I would be needing if I wanted to make a room quiet. As in, people would sound like they’re talking softly even if they were talking loudly. Am I looking to absorb sound then?

    Cheers,
    Nancy

    • Ted W

      Nancy,

      Thanks for the comment. I am going to assume that you are looking for absorption through out the room. It is important, however, to understand that by placing panels on the walls and ceilings of a room, the result is going to be a reduction ion the sound pressure in the room and a reduction in the reflections that a listener would hear from reflecting from the surfaces. If two people are talking loudly, the sound from their mouth still goes straight to their ear – THAT path of sound transmission is not affected at all. It may sound a BIT quieter because your ear will not be picking up reflections from the surfaces around them, but the only way to make people sound like they are talking softly is to ask them to talk softly.

      I hope that makes sense. Let me know if you have more questions. Thanks,
      Ted

  50. Rudi Kirner

    Hi Ted,

    Thank you for the information in your post. I would like to reduce the noise going to my housemates rooms that my small parrot makes. He has a high pitched squawk. I am on a budget and am considering just sound blocking the cage, which is 60″x30″x30″. The issue is that I will need to keep one side open, therefore it seems that sound blocking will just reflect the sound waves out of the open side. Can you suggest anything short of sound blocking the whole room? I was thinking of using absorption material, sandwiched with blocking material on the outer side, around the cage and facing the cage away from neighboring housemates. I could then line the whole room with something cheaper. What would be the best combination? Many thanks in advance.

    • Ted W

      Rudi,

      Thanks for the comment. This is going to be a very difficult situation and unfortunately my news isn’t going to be what you are looking to hear. In order to block the sound from the bird, you are going to need a fully-enclosed room. If you have any common air space that connects a listener to the noise source, the sound is going to travel through the air.

      Sorry!
      Ted

      • Rudi Kirner

        Hi Ted,

        Thanks for the reply. From your analogy of sponges, it seems that absorption material won’t prevent sound from escaping, but will reduce the ‘flow rate’ at which it will pass through. Would this change the frequency of a noise audible to an outside listener? I’m wondering how a high frequency sound could be transformed into a low frequency sound, without blocking.

        Thanks,
        Rudi.

        • Ted W

          Rudi,

          The analogy isn’t perfect — I will be the first one to admit that. It’s basically just to get the point across that products that ABSORB sound do not BLOCK sound.

          You may see a small amount of reduction on the outside of the room by introducing absorption and lowering the sound pressure and strength that you have in the room, but it will ALWAYS be more effective to use a BARRIER type product to block sound than it will with an absorber.

  51. Sansh

    Hi

    Useful article. I have been diagnosed with severe hyperacusis and i live in india. here there are no doctors who have ever heard or seen a hyperacusis case.

    i live in the corner of 2 high roads intersecting. i’m looking to sound DEADEN my room. Any help would save my life(not exaggerating).

    thanks.

    • Sansh

      more info:

      the walls are made from bricks.
      the windows and doors are wooden. now we’ve added glass door but still the sounds are not blocked.

    • Ted W

      Sansh,

      Thanks for the comments. I’m very sorry to hear about your condition. Unfortunately, I am not familiar with the common and available building materials in India, but the physics that I mentioned in the article are going to be consistent and applicable wherever you are. You first need to make your wall as airtight as possible — sealing any and all gaps and cracks anywhere they might be present. After that, it comes down to mass and density — the heavier something is, the more sound it is going to block. You may benefit greatly from covering your windows with wood or brick and making them as airtight as possible.

      Sorry I am not able to offer more help. Please let me know if you have any more questions.
      Ted

  52. Sansh

    hi

    thankyou for the reply. the windows are made from wood. the problem is I still need air to breathe and with air comes sound. I read that vacuum blocks sound. is there some way I could implement that? I checked the links you have given for the sound BLOCKing materials. but vacuum is needful for me.

    • Ted W

      Sansh,

      If you have air, you have sound. You can not have one and not have the other. Sound travels through air.

      Have you explored a nice set of headphone-style hearing protection?

  53. gary

    Hi Ted,

    Thanks for the above article. I have a major problem that isn’t gonna go away. Tried police, council, landlords etc but these ‘people’ are just disrespectful in the extreme!

    We live in an old building, ground floor flat. It is very small so any noise upstairs, and there is a lot – especially at weekends – travels through the whole house. I had a brainwave this morning which requires the advice of an expert such as yourself to check it is even conceivable (unfortunately probably not but I have to try!).

    I wondered about a sound proof capsule that we could sleep in. The noise would be bearable if it wasn’t for the fact that, at weekends, it is all night long. Have you ever heard of such a concept? Would it work? Any advice would be greatly appreciated. This is affecting my health greatly.

    Kind Regards,

    Gary :0)

    • Ted W

      Gary,

      I’m sorry to hear about your situation. Creating a sleeping chamber may or may not help — it really depends on two factors — 1) how the chamber is built and 2) the severity and nature of the problem. You could absolutely build a room within a room which, I assume, is your thought. There are a few very important things to consider, though. In a situation like this, it has its challenges.

      The first thing to consider is airflow. In order to block sound, you have to block air, which is typically needed while sleeping. You will need to acoustically treat at least two chambers to get air into and out of the small room — being sure to acoustically line them and force both sound and air past at least two 90° bends. One thing to consider is that if there is a fire, you will not hear the fire alarm, which could be a really bad situation.

      When I mentioned the type or nature of the problem, the reduction of the sound is going to be directly relative to frequency (high vs low pitch) of the sound as well as whether or not this is a vibration-borne structure energy. If the nature of the problem is sound created by a sub-woofer or bass drum, it will be incredibly hard to reduce effectively due to the length of the sound wave. If the structure is literally and physically shaking, you will need to build this room on spring isolators to decouple it from the structure.

      If this is something you would like to explore more, considering the factors above, please let me know and we can discuss wall construction and assembly, floor and ceiling assembly, and ventilating the space.

      Thank you,
      Ted

  54. Peyton Rowan

    In the 1990s I owned and remodeled (redesigned) a small two bedroom condominium. It originally had walls of wire mesh and a plaster wall for one bedroom and a sliding wooden panel in the other bedroom for a wall between that bedroom and living room. There was a small bathroom between the two bedrooms. The doors to the bathroom and bedrooms were hollow core. I used metal frames and sheet rock for walls in all spaces. For “sound proofing” between rooms I used acoustical ceiling tiles to fill (i.e., more than one tile thickness) the space in the metal frames and installed solid core doors. It worked great. Could knock hard on the sheetrock between any room and just barely hear a sound on the other side. The floors and ceiling were concrete. Hung ceiling tiles (on frames) in one bedroom but the concrete ceiling sagged so much it was very difficult to set the frame; so I used ceiling tiles glued to the ceiling in the other parts of the apartment. The glued ones seem to work fine. Also, made sure when using ceramic flooring tile or wood to isolate the apartment below.

  55. Peter Maich

    Hi Ted, I am building a small Anechoic chamber in my home for use in sleep study and sensory deprivation for the induction of lucid states, an area when I have extensive understanding and a life time of experience.

    I have an external chamber lined and sound proofed and soon to begin constructing the internal chamber which will have an internal volume of approx. 10m3. I will line this with some form of sound proof rock wall or acoustic board and am seeking advice on what to this chamber with to supress echo’s.

    I am wanting to create an environment that is as quiet as possible for maximum sensory deprivation and from this base look at potential sleep chamber design.
    The is no internal noise generation other than what my body will produce, blood flow, hear beat and other organ noise.
    Look forward to any advice you may have for an echo absorbing wall lining
    Cheers
    Peter

    • Ted W

      Peter,

      There are a few different ways to approach a situation like this, depending on what you want the space to look like and how much work you want to do. All of the anechoic chambers that I have been in have used Melamine Max Wedge foam panels in an 8-12″ depth. Because of the foam itself, the size, and the shipping charges — this can be a quite costly way to go.

      You could also look at stacking up a few layers of the Bass Buster or Ultra Touch insulation, both of which are cotton-based products. Although these cotton products can, technically, be used as a finished surface, you would probably want to cover them with a stretch-fabric system to encapsulate the dust particles that are inherent to cotton-based products and also to create a more finished look.

      Please let me know if you have any questions. Thanks,
      Ted

  56. Liz Andrews

    I lease one room in an office suite where I would like to block sound coming from the lobby (like conversations) when I am in my office. I have a hollow core interior door. I am leasing the office space so I cannot make major modifications. I was wondering if there is something that can be attached to the inside of the door that would help. Even if it cuts down only 30% on the outside sounds, that would be a big help. I am a hypnotherapist, and even though I already use white noise machines, I can still hear occasional voices outside my door when people walk by. I currently use a door sweep at the bottom of the door but I quickly realized that is not enough since the sound mostly comes through the door itself. The door fits pretty tight in the door frame, because I have tried adding weather stripping but then the door doesn’t close. Is there any type of board (or something similar) preferably white like the door, that could be nailed to the door? My landlord wouldn’t object if I tacked something on the door, I’m sure.

    • Ted W

      Liz,

      I will do my best to explain and help, but if you have any questions or wish to talk about the problem for a few minutes, please feel free to call. The only thing I ask is that you don’t hypnotize me. :D

      Sound always travels via the path of least resistance, which it sounds like you know. You may benefit from an adjustable door seal kit, or maybe not. The door seal kit will not inhibit the use of the door like weather stripping will because of the ability to adjust the pressure and amount of contact. It might be something to look into. But, to answer your question, there is a direct relationship between the mass and density of a surface and the amount of sound that it blocks. The heavier the better — which is why a heavy solid-core door blocks more sound than a light hollow-core door. There is nothing wrong with attaching a piece of dense, heavy, and commonly available sheet-good like 3/4″ MDF board (a heavy plywood-type board) or a piece of 5/8″ sheetrock. You could always get creative and wrap fabric on the board before it goes on the door — or adhere (or even use Velcro(R) or double-sided tape) a piece of decorative wood/veneer/etc to the office side of the board to dress it up a bit.

      We do have a few products that other people have used in the past if this doesn’t or isn’t going to work for you. I have sold quite a few acoustical quilted curtain panels that have been attached to a track over the door and slid into place (like a barn door sliding from left-to-right) when the soundproofing is needed. The product is too heavy and dense to pleat like a piece of fabric, so a standard curtain rod is not enough.

      Here is a picture of a customer who did something like this in their house for a music/practice room. This option is fully removable — the only work you would need to do is patch the holes left by the screws/bolts that hold the track to the wall (or ceiling).
      Quilted Curtain Covering Door

      Let me know if this helps at all and if you have any more questions.

      Ted

  57. Patricia Murtagh

    In my kitchen /dining area it is difficult to hear conversation and this gets much worse when there are more than 2 in the room. The room is 24ft long x 12ft wide. Half of it – the kithen half – has a normal height ceiling (8ft high) and the other half – the dining room part – has a double height pitched ceiling, which is clad in timber. There are four velux windows in the timber ceiling. Walls are brick and plaster, floor is lino. I now understand that all the hard surfaces and high ceiling create the poor sound quality in the room. Can you suggest anything to fix this? On the high wall between the kitchen/dining area I was going to cover some acoustic foam and hang it up, an area of 7ft x 4ft approx. I dont want to put anything on the ceiling as I like the timber look here. Will this foam make any difference of do I really need to put more up on the opposite wall? Appreciate any help you can give.

    • Ted W

      Patricia,

      Residential problems like this are some of the most difficult types of situations that I am asked to approach. There is a direct relationship between the cubic volume of the room, the surfaces in the room, and the amount of absorptive material one needs to make the room more comfortable and easy to use. The difficult part is that homes are now being built with open floor plans and very nice looking hard surfaces. The bigger the room is, and the more hard surfaces there are, the more severe the echo is and the more panels it takes to reduce the problem. Introducing panels into the space inevitably means covering up the surfaces in the room now with a different surface, which will obviously change the aesthetic. Getting enough absorption into the room while not totally tweaking the aesthetic can be very tricky.

      Relative to the size of the room, I would probably suggest starting with right around 80-100 sq. ft. of panels, which is going to take the edge off the room and make it much more comfortable. The area of 7′ x 4′ that you mention is only 28 sq. ft. of surface area, which may or may not make an audible difference in the sound quality of the rooms.

      I would be happy to take a look at a few pictures of the area if you would like to send them to me.

      Thanks,
      Ted

  58. Liz Andrews

    Ted,

    Thank you for the suggestions. This gives me a lot to think about, and it is good to know that there are possible solutions.

    Best,

    Liz

  59. Aiyad

    Hi Ted,

    Thank you for the great article. and your great effort to get back to people who comment.

    I do have a question though. So in some home listening room, foam panels are placed on key areas on the wall to stop the sound from reflecting off the wall and coming back to your listening position, which improves the sound quality at your position.

    So if the sound isn’t reflected back by the foam, nor does the sound disappear (as if you place those foam panels on some thin door, it wouldn’t make much difference on how much sound you hear on the other side) , then where does the sound go?

    • Ted W

      Hi Ayid,

      Glad you enjoy the article. Just so we are on the same page — I am not a professor of acoustics — I am a guy in an office and work in the acoustics industry. I have enough of a grasp of the physics to explain them to people in general terms that hopefully increases a general knowledge of acoustics and sound. (If you really want to know more of my background, read this post.)

      I’m going to pick apart and highlight some of your words — not to embarass you — but to, hopefully, help you understand things a bit more clearly.

      You ask about panels being placed on key areas on the wall to stop the sound from reflecting off of the wall and coming back to your listening position, which isn’t quite accurate. Acoustical panels have porous surfaces (like a sponge) so that the sound waves that get into the panel through to pores get lost in the matrix/maze of the panel. A good acoustical panel allows sound to pass into and through them easily so that the sound that is left once it gets to the wall bounces off the hard wall and comes back through a different maze. As it does this, it loses energy. So, rather than the panel stopping reflection, the panel reduces reflections.

      Here is a great video on How Sound Works (In Rooms) that goes over a few other things, but there is a part in there where absorbers are explained with a visual (at about 1:50 in the video).

      Hope this helps. Thanks,
      Ted

  60. Eduardo

    Hi Ted,

    Thanks for sharing your tips. I have a fountain in my office because I like the noise water makes, but the little water pump makes more noise than the water itself, which is pretty annoying. I want to make a new fountain made of wood – Japanese style, but before I do I want to know if I can prevent this from happening again. Fountain base will be around 10×20″ and around 20″ high.

    Thanks
    Eduardo

    • Ted W

      Blocking sound is generally going to involve construction, and to answer your question, it is very likely that I can help you. But, at this point, I don’t know what to suggest because I do not have enough information to start to offer suggestions. Could you tell me more about the space so that I can better assist you? Could you send a few photos of the situation so I can visualize the problem?

      Does the kitchen area and the dining area have any shared airspace?
      Is there a wall that separates these two rooms?
      Is there a door in the wall?
      What is the wall construction?
      Are there any blowers that are mounted onto the common wall?
      Is the hood isolated from touching the structure?

      These are a few questions that I will need to discuss with you to better assist you.

      Thanks,
      Ted

  61. Alina Weidell

    Hi,

    We live in a townhome that shares the same floor with the other 3 (it’s a quad). The bedroom in by the street and the driveway is in front of the bedroom. We were trying to block some sound from the outside, especially buses or the newspaper delivery car. Also, the sound coming from my neighbor (like when she closes the dresser and things like that). My husband put a thicker drywall and added a special sound proofing sheet from Menards in there on 3 of the walls (outside wall, the one to the neighbor and the one to the other room). I thought it will be much quieter but it doesn’t seem so. The outside wall now blocks some of the sounds, but it seems to allow more of the low frequency sounds like the rumble of the newspaper delivery car or the sound of the school bus engine. I also noticed a stronger echo in the room (when I clap my hands for example). I don’t hear the neighbor as loud (I would say a 30%) noise reduction but the street noises are still bothersome, the low frequency ones seem louder, and although I use a very loud white noise maker I can still hear them. We bought thick curtains that cover the outside window on top of the blankets that we put there and the blinds. There is furniture in the room and carpet on the floor. The walls do not have anything on them, but I want to buy some canvas prints.
    Can you please give us some suggestions? Thank you very much.

    • Ted W

      It sounds like there are a few different things going on here. Based on the descriptions of the problems above, I don’t know if there is much that we are going to be able to do. Whenever dealing with acoustics and sound problems, it is important to understand that the lower the frequency, the easier it is for that sound to get through whatever you put in front of it.

      So, if you have made some improvements to the space and you had a low frequency to begin with, it’s not surprising that your improvements reduced some of the high frequencies, which make the low frequencies seem louder.

      One possible product that you may benefit from would be Climate Seal window inserts. They are essentially a clear piece of acrylic plastic that has magnetic bellows around the perimeter — like the seal for a refrigerator door — making it as air tight as possible. They are held in place with magnets and typically do a good job at blocking sound — assuming the sound is coming in through the window and not a wall-mounted air conditioner or some other weak link like a space between the window and the rough opening, or some other airspace. But, like all other products, it does not perform as well at lower frequencies than it does with mid or high frequencies.

      The situation with the neighbor closing dressers could be an impact noise issue, which is usually approached differently.

      Acoustical panels inside of the room will absorb the echo that you mentioned, but they will not reduce sound transmission.

      Thanks,
      Ted

  62. Andrew

    I am wanting to create a quiet space in my house for taking business calls (help desk). It doesn’t need to be sound proof, just dampen noise enough that it won’t be heard over a headset phone. I have two dogs that will be in the house and I’m concerned about barking. Our doors are hollow and don’t block sound at all. Any ideas on how to either quiet the entire room or maybe just around my desk? I’m hoping to do it as cheaply as possible and without putting holes in the current wall. Any suggestions would be helpful.

    • Ted W

      Soundproofing a room — or even trying to reduce the sound that is entering or leaving a room is very specific to the room itself. What is done in “this room” is very unlikely to be the best way to treat “that room”.

      I would start by replacing the hollow core door with a heavy, dense, solid core door and getting a door seal kit for around the edges of the door. Making the door air tight can have a significant impact on the amount of sound that is reduced. I would also strongly suggest watching (or having the installer watch) our sound-rated door installation video — paying close attention to the details about getting the new jamb into the rough opening. (You can also print out the sound-rated door installation instructions pdf.)

      If the new door and gasketing is not enough for your needs, I would want to find out where the sound is getting in at that point. Is it the ducts to the room? The walls themselves? Is it through an outlet in the wall? Is it still coming through the door?

      If you don’t want to go through the trouble of replacing the door, another option would be to install a BSC-25 Quilted Barrier Curtain on the office side of the door. This is not a fabric curtain that can be drawn to one side like a shower curtain. This is more like a moving, solid blanket with a layer of lead on the inside. In can be installed on a roller-track (like a barn door) and drawn completely to one side if there is an open space next to the door. Here is a picture of one that I did with a previous customer in his residence:
      Quilted Curtain Covering Door

      These are not the only options, though. So, if neither of these are feasible, please let me know and we can look into it further.

      Thanks,
      Ted

  63. Stanley

    Hello Ted,
    Thank you very much for brilantly explain soundproofing and sound absorbing materials.
    I may ask you for your opionion and advise.
    We have moved our Real Estate office in Manhattan to almost indetical space as we use to have where we had no acoustic issues what so ever. We are seating in open loft type of office environment with no drop ceiling, our desks are in same position at they use to be may be a foot closer space is about 3 feet narrower.
    Now in new space we all are hearing each other, conversations are echoing through the space. Person seating far on the other side is louder than person seating closer. We created two glass offices in case we do not close the door we can hear everything what is being said in that office, glass offices sounds like speakers.
    The main difference between our new and old office is the celling. Our previous office use to have open flat ceiling our new office have wavy industrial ceiling please see attached picture.
    What is your advice to lower the voice travel through our office space. We can install 6 to 8 high class partitions but we are not sure if this will solve our problem. We could install two feet hanging ceiling partitions but we are not sure what would be the better solution.
    Thank for your expert opinion.
    With regards,
    Stanley

    • Ted W

      The first two products that come to mind would be the Echo Eliminator recycled cotton panels and the Fabric Wrapped Fiberglass acoustical panels. These panels perform nearly the same, but their respective advantages and disadvantages are considerably different.

      The cotton panels are economical, in-stock in 2′×4′ panels in ten different colors, lightweight, easy-to-install, and made from recycled cotton. They are, however, not as aesthetically pleasing or finished looking as some folks want/need. They look and feel like a 1″ thick piece of felt. My initial thought would be that the 1″ #3lb white panels would do well mounted directly to the ceiling.

      The fabric wrapped fiberglass panels are custom made and much more decorative and aesthetically pleasing. They are available in any quantity and sizes up to 4′×10′. There are literally a few hundred different types of colors and styles of fabric to choose from, so they can be made to work with or accent an existing aesthetic.

      One nice thing about acoustics is that the location of the panels is not nearly as critical as the number of panels installed into the room relative to the size of the room. When you are trying to reduce the overall echo and reverberation of a room, you can, essentially, put the panels wherever you want and get the same general reduction. Glass partitions would not likely make any reduction or change to the space.

      Hopefully this helps. Thanks,
      Ted

  64. David Alexander-Watts

    Dear Ted

    I have a different requirement for sound insulation from the examples above as what I am looking to do is to reduce the noise of an outboard engine in my boat.

    On my sailboat, the engine sits in a well in the cockpit, right beside the person helming the boat. It’s quite an intrusive noise, especially if I need to motor for some time, for example if there isn’t sufficient wind to sail.

    I would like to reduce the noise of the motor ( a standard Mercury 6hp 4-stroke) and am considering making a “hat” to fit over the plastic engine cowling. This won’t cover the engine as I need to leave space for ventilation and exhaust gases, but I am hoping it will at least take the edge off the noise.

    Do you have any thoughts on a suitable material and thickness levels needed? The material should be waterproof but it would only be used when I am on the boat so does not need to be completely weatherproof as I can store it out of the elements when not in use.

    • Ted W

      I think a picture of the motor relative to the helming position might help me help you on this one, but the first product that came to mind would be one of the Quilted Curtain options. There is a standard interior grade curtain as well as an exterior grade curtain option. These are custom-made barrier and absorber blankets that can be made to any size. They can have grommets and/or hook-and-loop added to connect one panel to the one next to it.

      Again, I don’t know what the space looks like or the particulars, but my mind’s eye came up with a picture of a little Merc motor with a 1/2″ or 3/4″ PVC pipe frame around it that could potentially be removable relatively easy with strapping of some kind. The frame would support a four or five sided “box” or “dog house” that you would bring out of the storage area of the boat and zip-tie or use hook-and-loop tape to hold it in place over the frame.

      I can just about guarantee that as long as it was made the right size that you wouldn’t hear a 6hp motor if it covered most of the motor — and hid it from view.

      Let me know what you think. Thanks,
      Ted

  65. Georgia

    Hi Ted,

    I live in NYC and am in apartment with dry walls and crappy floors. When I lie on my bed all I can hear is a low base frequency or bass noise coming from other apartments.

    What would you suggest I do to block out this noise from coming through the pillow?

    Thanks

  66. Greg

    Hi Ted,
    I’m moving into a new apartment and will be bringing my small home studio with me. I’m on the bottom floor and the studio will be against the wall to outside so the main surface I’m worried about is the ceiling. I just don’t wanna tick off my neighbors so I was wondering what you would recommend for overall sound dampening and eliminating as much sound from traveling through the ceiling as possible.
    Thanks!
    Greg

    • Ted W

      Most of the time, residents in apartments can not make any modifications to the structure. So, unless you can make structural modifications to the ceiling (adding a layer or two of drywall), I would invest in a great set of cordless headphones.

      If there is ANY bass/low frequency downstairs, it will be heard and probably felt in the floor of the upstairs unit. There isn’t a cheap, easy and/or temporary sound barrier that one can use in an apartment to block sound. As noted in the article, blocking sound is done to the structure and is not accomplished with a wall panel.

      Thanks,
      Ted

  67. Helen

    Hi Ted,

    We bought a small town home and had to have the furnace replaced with a high efficiency furnace. The furnace noise is really annoying, particularly the sound of the intake air pipe. I should mention that the furnace is located in a small room off the kitchen. The main problem is the sound of the air intake pipe and the blower at night, which often wakes me up. The bedrooms are on the second floor and the furnace is quite loud in all the 3 bedrooms. We are wondering if it would help to insulate the furnace room. Would it deaden or at least soften some of the noise coming to the bedrooms? Our furnace installer said he has insulated some of the furnace rooms in other similar town homes because of the same problem, but he did not think it was that effective. Any suggestions? Thanks!

    • Ted W

      This is another situation where it is VERY difficult to try to offer suggestions and recommendations because this is SUCH a site-specific type of problem. It’s nearly impossible for me to start to recommend products. Is the sound coming through the HVAC ducts with the air? Is it coming through the walls? Does the air-intake introduce any vibration energy into the walls/structure? Have you tried using any white noise or background noise in the room while you sleep?

      Typically speaking, installing acoustical panels in the room will quiet down the utility room itself. This can help a LITTLE bit, sometimes, but they are not a sound barrier and are only used to absorb echo within that room. If that room is quieter, the sound pressure leaving the room can be lowered slightly — but this does depend, significantly, on the nature of the problem. If the pipe is vibrating/shaking when the machine is running and that pipe is touching a stud or some sheetrock, it can introduce vibration that will present like an airborne noise in other parts of the house.

      Sorry I am not able to offer any specific solutions, but there are simply too many variables at this point.

      Thanks,
      Ted

  68. Dale Jay Kredit

    I have purchased a commercial refrigerator for my house that works really well but it’s very loud.
    I contacted the manufacturer and they confirmed that’s normal. The compressor is just setting in a metal box and does require air flow, so my question is what would be the best process to reduce the sound coming from the unit?

    • Ted W

      Is the refrigerator tucked into a cut-out in a room and surrounded by drywall? Often putting some absorptive panels on the three walls around the machine can greatly reduce the sound pressure that reflects off of the drywall and projects out into a room. If you have a photo or two of the situation you can send me, I would be happy to take a look and offer a potentially more specific recommendation.

      I have used both of these products in my own kitchen. The Quiet Liner is a product I installed in my dishwasher area (under the counter) and the Echo Eliminator panels were put on the wall right behind my refrigerator. I used the black Echo Eliminator (rather than the Quiet Liner in both locations) because it can be potentially seen, and the black just looks like a shadow.

      Thanks,
      Ted

      • Amy Carter

        I actually have a similar question regarding refrigerators/freezers. We have a situation where we need to move two -80 freezers into a lab room full of people, unfortunately the freezers make a constant loud white noise. Therefore we’re hoping to reduce or block the sound so that the people working in the lab aren’t driven completely crazy by the noise. The -80′s would be up against only one wall (they don’t sit in a inlet), otherwise the rest of the freezer is exposed to the large spacious room. In that case do you still recommend sound absorbing pads?

        • Ted W

          Without knowing too much about the situation, I would probably suggest starting by putting some kind of absorptive material on the walls behind the freezers to stop the sound from bouncing off of the wall and being projected to the rest of the room. If that type of approach doesn’t get you where you need to be, you will need to put a two-or-three sided enclosure around the freezers and interrupt the line of sight with a barrier-absorber panel such as a quilted curtain. Here is an example of a quilted curtain enclosure.

          These enclosures or walls are all custom-made and can be hung from an overhead track system similar to tracks used for barn doors or hospital curtains. We can use a double-track system like a patio door so that some of the panels can slide behind the others. We can also ship them with clear vinyl windows where needed so that people in the room could see into the enclosure.

          Let me know if you have any questions or if you would like to discuss this further.

          Thanks,
          Ted

  69. Mihai

    Great post, Ted! Do you have a suggestion for what I could do to let the kids play with a basketball on the room’s wooden floor, but not annoy the neighbors below? Thanks.

    • Ted W

      Unfortunately, no — not without SIGNIFICANT modifications to the floor/ceiling assembly. That’s a tough situation because the ball introduces way too much energy into the structure. You could get a lighter — foam or inflatable — basketball, but that’s not really the same. Sorry!

  70. Rob

    Do do I keep sound entering my babies room? Do I need to soundproof my room to stop the noise escape, or vice versa. Also it’s also the kid upstairs too. Can I drown him out so to speak? Or will I need a shotgun ;-)

  71. Ems

    Hi, The back wall in my sons bedroom backs onto the lift (elevator) that services the block. Its a loud sound, I thinking cable movement, one can also hear the automated voice assistance from the lift. Due to the design of the room (window location) my sons headboard will be on this wall. I am desperate to block this noise. Please suggest the best method. Thank you. Ems

    • Ted W

      Sound is blocked with mass and density, so if you can add a locally available, standard building material to the wall simply to make it heavier and more dense, the sound should be reduced. You can also put a fan or a similar, small, white-noise machine in the bedroom to create a comfortable, but louder, background noise inside of the room, which always helps.

      Thanks,
      Ted

  72. Mary Ann Massaro

    Hi,
    Living in a condo. My bedroom is back to back with my neighbors and so are our headboards. I can hear their TV and voices. We tried green glue which helped somewhat but I think It helped them more than us. Their voices wake us up at 12pm when they go to bed. Someone gave us some information about Isole Sound Absorbers. Any thoughts as to what we can do short of ripping out the entire wall and soundproofing the room.
    Thank you,

    • Ted W

      Because you have already added the Green Glue and presumably another layer of 5/8″ sheetrock and that was not enough reduction for you, the next step is to get into the construction of the wall more aggressively.

      Have you tried using any kind of white-noise machine in your bedroom? Do you have the ability to send me any information on how the wall was built? Typically the condo association has that information. There is no doubt that tearing into the wall and re-building or significantly modifying it is a huge and messy pain in the rear end, but sometimes it is the only way to reduce the sound enough so that your living space is comfortable.

      There are a few ways to do that, so if it’s something you’re willing to consider, please let me know and I will do my best to help.

      Thanks,
      Ted

  73. sunny

    Hi there
    I live in an apartment near freeway.I have very big ceiling to floor windows.the ongoing traffic noise specially of the heavy trucks drving me nuts.Can you please advice me how to reduce or block this noise through the window.

    • Ted W

      Unfortunately this situation can be relatively costly to approach. The two products that I have are the Climate Seal Window Inserts and the Acoustical Quilted Curtain. These are both custom made products and, depending on the size and details that need to be made to accommodate your situation, can get expensive. They often aren’t a feasible option for an apartment or relatively-temporary living situation simply due to the investment that is required.

      I would be happy to draft a quote for you if you would like to contact me with your address, phone number, and the sizes and quantities of windows that you are considering.

      Thanks,
      Ted

  74. Tony

    Hi Ted,

    I live on a busy street. My bedroom is on 2nd floor and the 2 bedroom window is parallel to the busy street. Do you have a solution to keep the wind friction cause by car driven by out or reduce to a minimal? Please provide a quote for 2 window with the following measurement: height is 46.5in, width is 58.5in and depth is 3in from the existing window panel.

    Thanks

    Tony

    • Ted W

      I have two potential products that can reduce the amount of sound coming through the windows. They are the Climate Seal Acoustical Inserts and the Acoustical Quilted Industrial Curtain panels.

      The Climate Seal acoustical window inserts would cost roughly $788.00 for both windows. This price would include the perimeter metal angle needed.

      The Quilted Curtain panels would cost roughly $580.00. This would include a row of grommets across the top of each.

      Please understand that these products are both custom-made on a per job basis and freight would be additional depending on your location. If you would like me to draft up a formal quote, just send me your address and phone number.

      Thanks,
      Ted

  75. Jeremy

    I have several roommates who make lots of noise in the room adjacent to me. I cannot adjust the wall material because I do not own the property. Earplugs work but they are bothersome and cause earaches after wearing them for a while. Is there a way to make a soundproof helmet-type device that is not cumbersome?

    • Ted W

      Unfortunately there is not a way to feasibly make a soundproof helmet that is any better or more effective than a pair of hearing-protection earmuffs like the one would use while operating a chainsaw. These types of products exist, they are not cumbersome, and they are very cost effective. In theory, we could potentially design something to do the same thing, but it would be much more costly.
      Hearing Protection Ear Muffs

  76. Kenneth

    Hi, I am Planning To Do my home theater acoustics by my own.
    i have planned to use wood wool board for sound absorption, Glass Wool for sound Proofing , so my question is can i use wood wool, second can i fix the wood wool board completely on all the walls in my room so there will be a theatrical effect , if not where should i place those boards ? third Should i place the absorbers in the ceiling? Fourth Should I use diffusers ? My Home theater room size is 25 feet long, 15 feet wide, and 10 feet in height. Please Reply. Thank You In Advance

    • Ted W

      Unfortunately, I am not able to provide you with much information beacuse I am unfamiliar with “wood wool”. Home theaters are rooms that need to be done very specifically to be done properly. I would strongly suggest calling a company that specializes in theater construction and asking them the questions above. We do theater and studio work specific to people’s needs, the layout and geometry of the room, as well as the type of sound that is being played in the room.

      You will likely need panels on both the walls and the ceilings. You should probably use a combination of diffusors and absorbers.

      Thanks,
      Ted

  77. Ledley

    Hi
    I wake everyone up early as we have a very noisy power shower. Is it sufficient to put something under it, or should I try and contain the whole pump in some form of box?
    What materials should I use for either please. Thanks
    Leds

    • Ted W

      There are unfortunately way too many variables involved with a situation like this for me to try to start making assumptions and suggestions about how to fix the problem. If it is a vibration-borne energy that is shaking the structure around the pump, you will need rubber, or preferably spring isolators. Additionally, if you isolate the pump and the pipes that are connected to the pump touching the structure that are vibrating, that energy still has a path to get into the structure. If it is completely decoupled and floating, and it is just a loud pump, you would likely benefit from some kind of box or enclosure around the motor. But, that introduces the issue of the pump’s air exchange so that it does not heat up and fail.

      I’m sorry I am not able to make more specific recommendations, but I just don’t have enough information.

      Thanks,
      Ted

  78. Mary

    Hi Ted,
    I enjoyed your article. I’m wondering if you would have a suggestion for my situation because I am at a loss and getting desperate. I moved into an apt building that is a renovated department store. It seems the walls were built on top of the hardwood floors of one open space with no sort of insulation, like one big house instead if separate apts. I can hear every step the neighbors take, every word they say, every sound as if it’s in my apt and I’m assuming they can hear me too. The sounds also echo. The ceilings are 12′ and there are pipes to a sprinkler system that run overhead through the apts, if that means anything. Do you think panels would help with this at all since I am renting and can’t do anything about the construction of the apt or do you have any other ideas? I don’t have space to construct anything so I need something premade or cut to size. Thanks!

    • Ted W

      Unfortunately my news isn’t going to be good. The only way to start to reduce these types of problems are construction-based methods.

      There isn’t a “cheap and easy, and temporary” acoustical panel that will offer you much benefit at all. As I noted in the article, the panels that are “cheap and easy” and that can be mounted temporarily are products that are used to control echo within the room and it sounds like 98% of your problem is sound-transmission related.

      I would be happy to do my best to discuss a few potential products with you, but all of the products that I have to start to reduce the airborne sound from one unit to the other are construction grade, permanent products or building methods.

      Sorry,
      Ted

  79. Mary

    Hi I live in the end a one level unit of 3 with a firewall between me and the middle unit.When I bought I could hear almost everything from the next unit like the TV the phone talking walking on the wooden floors etc.I had a double black block wall constructed on my side &was told that the neighbour had to do the same to cut out all noise.They didn’t I was also told that unless the neighbours did the same in certain circumstances the wall could act as a speaker to conduct noise. A new tenant has moved in recently and the noise and intense vibration is horrendous. They have a large aquarium up against my bedroom wall. I’ve told them & they appear to have only moved it an inch from the wall. They say there is no noise on their side.The noise and vibration is so bad at times my ears ache.Ican feel the vibration in my body&my head on the pillow

  80. CJ

    Hi Ted, great blog! My husband and I just built a new home, and our master suite is situated off the great room/kitchen area. Our new fridge is noisier than I expected (though I bought an advertised “quiet” model). The dishwasher’s also louder than expected, but again, we got a “quiet” one. :/ Is there a product we can place under both of these appliances to quell the noise? Thanks.

    • Ted W

      There are a few possible things that could be going on here, but I have a few ideas to pass along which will hopefully help with the most common or likely. Appliances like this have motors and parts that not only run and create airborne noises, but also a bit of vibration energy that can be transmitted into the floor and/or the structure around them. Those two types of sound problems are approached differently, which I will try to explain.

      The most common initial problem to approach is the airborne sound that is being made by the machine operation. Both refrigerators and dishwashers are very commonly installed into enclosures made of hard surfaces. After all, who would want their refrigerator hanging out in the middle of a kitchen? Considering they are surrounded by hard surfaces, all of the sound being made only has one place to go and that’s out toward the middle of the room. The drywall and cabinets around the refrigerator simply reflect the sound until it leaves the area.

      The product that I have used, personally, to fix this problem at my house is the 1″ Quiet Liner. This is a roll of recycled cotton fiber – 4′ wide and sold in 5 linear-foot increments – that has a black, anti-microbial fabric on one side. It is very cost effective and does a great job. It is not the most aesthetically pleasing product in the world as it’s made to be used inside of enclosures, but if it’s behind a fridge or surrounding a dishwasher and you’re not going to see it anyway, does it really matter? One of the things you need to watch out for is allowing the machine enough room around it to “breathe” so that it doesn’t overheat. The cotton is Class A fire rated, so it’s not a fire risk, but it will hold heat like a blanket.

      If it is still a problem after this, we can talk about a few of the vibration-isolator options.

      Thanks,
      Ted

  81. karthik

    Hey good detailed explanation.I am building a house and i am concerned about few things
    1. Kitchen range hood noise, Its been placed against the wall with tiles so the noise is reflected back to our living room any suggestion would be appreciated.
    Thanks
    Karthik

    • Ted W

      I don’t have any solid suggestions for a situation like this as I assume the panel would be subject to relatively significant heat. Tile is inherently VERY different than acoustical panels and if you’re using tile for the resistance to temperature and the ability to be cleaned easily, there really isn’t an acoustical panel that can replace it.

      Sorry,
      Ted

  82. Lex

    Hi. I manage a high-rise condominium where the gym is below units. When people drop weights, the sound travels up for many floors. We currently have a rubberized tile flooring. how can I reduce the noise?

    • Ted W

      Unfortunately this is a very site-specific question and there could be MANY different ways that the sound is getting from the gym to the units above. A situation like this could be impact noise, airborne noise, or both — and unfortunately from my desk here, there is no way for me to know enough about the situation to start to recommend ways to approach it.

      The best approach in this case may be to consult a local acoustical engineer or consultant. I’m sorry I’m not able to offer better information.

      Thanks,
      Ted

  83. Janice McFadden

    I have noise coming from a high efficiency furnace venting pipe that runs under the bedroom. As the pvc pipe expands and contracts it makes ticking noises (like a fingernail clicking on a hard surface). In the quiet of the night this ticking is driving me crazy. The ceiling in the basement below is permanent.The floor in the bedroom is hardwood. Is there something i can put under the bed that will prevent the sound from coming through?

    • Ted W

      Unfortunately the best approach is to wrap the pipes directly, and while you’re in there, decoupling the pipes from the structure. You could possibly use something like the closed-cell barrier-decoupler (PVC decoupler) under a carpet or something, but I can’t really give you an estimation about the proposed reduction. Also, the barrier is a construction grade material, so it might off-gas a bit and it is not Class A fire rated. But, it’s the only thing I can think of to consider.

      Thanks,
      Ted

  84. brent

    Hi,
    I have a new 3 ton air central air conditioner installed above my refrigerator and ovens in a concrete block space 5′ wide, 2 ‘ high and 2 2/2′ deep.
    The front panel of this space has two air intakes and two outlets and because of the layout, it’s not possible to install ducting.
    Can you recommend a product that can be applied to the interior 5 sides of the space that might reduce the decibel level of the unit when it’s in operation – it’s very loud.
    Next step is to remove the unit and install a couple of mini splits.
    Thanks
    Brent

    • Ted W

      Without knowing too much about the situation, I would probably try Quiet Liner if it were a problem I were experiencing.

      This is a cotton-based product that has a black anti-microbial fabric on one side. It is sold in rolls that are 48″ wide and cut in five -linear-foot increments. It can be cut on site with a good sharp pair of scissors and installed onto the walls of the enclosure with a construction adhesive (Liquid Nails, PL-400, Powergrab Locktite, etc.) as well as a bit of spray adhesive (Super 77 or something similar) or we can send adhesive with the cotton if you would like.

      Comparing the cost to the absorption offered, it is a good product for a situation like this. I would suggest the minimum thickness as 1″, and if the sound that is bothering you sounds like a low-frequency (bass, deep noise), use the 2″ thick option if you have the space.

      I would be happy to give you a quote if you would send me your address, phone number, and approximately how many total square feet of product you think you might need. Let me know if you have any questions.

      Thanks,
      Ted

  85. Alfred Wong-Den

    Hi I have a problem where I get complaints coming from my parents bedroom about my tv being to loud when its not even 1/4 of the way now I know the wall is really thin and you can hear my phone conversations even when im talking at a normal tone of voice I was wondering if there is anything I can do to stop the sound getting to the other room without any construction of sorts

    • Ted W

      Unfortunately, blocking or starting to reduce the sound that is getting from one room to the next is likely going to involve construction. The only non-construction approach for something like this is a set of industrial-grade quilted-curtain panels that would need to cover the whole wall and any and all penetrations in the wall (like an HVAC duct). These look like industrial-grade moving blankets and are very heavy — as if there is a layer of lead in the center. Rough pricing is $14/square foot.

      Please let me know if you have any further questions. Thanks,
      Ted

  86. Anna

    Hi Ted! I have an issue with an open ceiling office space. I work for an interior designer and she designed an office space on the upper floor of a warehouse type building with a restaurant underneath. The space is quite large (I’m working on dimensions), and it is filled with cubicles which are lined with carpet. In order to add something interesting to the design, they went with hardwood floor runners in between all the cubicles. Once the office was up and running, they discovered that ladies shoes are quite noisy on that type of flooring. With the open ceiling, the foot traffic is too loud. Would sound absorbing panels on the ceiling or walls take care of any of that noise, or do you suppose we should switch to a carpet runner to muffle those heels? Thank you for any information you can offer!

    • Ted W

      Footfall can be tricky and the reduction offered by whatever you choose is going to vary depending on quite a few different things. Room sizes, floor/ceiling assemblies, people’s weight, people’s walking style, ambient (background) sound levels downstairs, etc, etc… A carpet runner would certainly soften the footfall a bit, but it may or may not be enough.

      It is unfortunate that the floor is already down and in-use because the first product that came to mind was the Acoustik Underlayment. This is a roll of a very specifically blended rubber that is made to reduce this type of situation and when it has been installed and tested in the field, it tests higher than other similar underlayments. This would add a minimum of 3/8″ to the floor, which may cause problems where the hardwood and carpet intersect. We do have the product in 1/4″ rolls, but you will get lower performance. In the interest of not adding too much thickness, that may be a good option, though!

      Let me know your thoughts and/or if you want me to send you any product samples. Thanks,
      Ted

  87. Helen Cordeiro

    Hi Ted:
    Thank you for the very informative blog!
    I am designing (2) 36″W x 84″H sliding slab doors for a bathroom and laundry room.
    I had specified solid core doors as a soundproofing measure. The problem is that these doors will be very heavy so I am trying to find a lighter alternative that will still provide a good soundproofing solution. Do you think constructing a hollow core door and insulating the interior core with homasote panels or rigid insulation would provide similar soundproofing as well as sound absorption?
    Thanks

    • Ted W

      Even more important than the weight of the door is the amount of air that connects the inside of this/these room(s) with the hallway. Sound pressure is always going to find the path of least resistance first, so making the doors as air tight as you possibly can is going to be far more important than the specs for the door itself.

      Let’s say, for argument’s sake, that the door(s) is/are air tight when they are closed. At this point, it all boils down to mass and density. The heavier something is, the more sound it blocks. The lighter something is, the easier it becomes for the sound to get through it. A heavy, solid-core door will block more sound than a hollow-core door.

      One possible option would be to install your lighter option, then once installed take a step back and listen. If you need to further reduce the sound, you might be able to install an additional “door” made from the quilted curtain panels like the one in the picture. These are essentially an industrial grade moving blanket with a very dense, heavy center layer (has the same density and properties as lead) and would sit on roller-tracks like a very heavy hospital curtain.

      Quilted Sound Blocking Curtain on Roller Track

  88. Tony

    Hi Ted,
    I really like this post, helped me reassure some assumptions I had. I have a small question for you. I recently bought a decent quality microphone (ATR2500-USB Cardoid Condenser) and I was setting it up and testing it. I’m having a problem with the echo I’m getting because I have very little furniture/wall furnishing and tile floors. I built a small 4 sided (top, back, left, and right sides) box out of cardboard and stapled carpet to the inside. It seems to help for now but I’m considering at a later date to outfit the walls with some sound absorption materials.

    The room is roughly 10×10 ft in size, tile flooring, 1 large double hung window, and one wall being about an 8ft closet door. My desk/workstation is to the right of the door on the same wall with my bed in the corner to the right of my desk and the window being in the middle of the wall to the desk’s right, and the closet on the left wall. I was looking at products online but wanted some advice as to what kind of products I should use. I’m looking mostly to just reduce echo and get a decent level of deadness in the room nothing extreme like soundproofing as I don’t get a lot of ambient noise from outside the room. I plan on setting up the room for voice-over recording so I’d like to get your opinion on what products i should consider. Thanks for the help in advance.

    Regards,
    Tony

    • Tony

      Addendum: I was also curious about the differences in different sound absorption materials such as eggcrate, wedges, and other surface designs of the foams.

    • Ted W

      My go-to product for a situation like this is Echo Eliminator panels. They are not going to offer the same aesthetic as a foam panel, but they have very good absorption numbers and are more cost-effective than foam panels. Foam panels are typically used when someone wants/needs a particular aesthetic. If this is a voice over room for your use, you may or may not want/need that particular product.

      To answer your question about the differences in sound absorption materials, there is a value/rating called NRC (Noise Reduction Coefficient). The NRC for our products are not on each corresponding spec page. The higher that number, the better. The surface pattern doesn’t necessarily improve or reduce performance.

      Depending on the ceiling height of your room and assuming you want to treat the whole room, I would personally start with 12-16 2′ × 4′ panels spaced out relatively evenly throughout the room. You could also start by treating one corner of the room and putting the mic between you and that corner. Many people opt to use a closet for voice-over rooms as treating a smaller amount of wall surfaces is always more cost-effective.

      Hopefully this helps! Thanks,
      Ted

      • Tony

        Thanks very much Ted! About how much cover am I going to need to be effective? 60-70% of the walls? Could I get smaller 12×12 panels and stagger them in a checkerboard configuration and get the same effect? In terms of mounting, we’re only renting the space we currently live in so I’m wary of using any mounts that might damage the walls or leave marks after removal, any suggestions?

        • Ted W

          There is no right or wrong answer to your questions — a lot of it is personal preference. The acoustics of the room will be increasingly reduced with the more panels introduced into the space. The point of diminishing returns is once you cover 60% of the overall surface area of the room, which is way more than you would ever cover in a situation like this.

          We do sell a product called Aco-U-Stick. The package comes with 6 12″ × 12″ squares of the 1″ thick Echo Eliminator cotton. It also comes with 3M Command™ strips for an easy-to-remove installation. You could also install them onto a piece of plywood and use some trim/finish nails to hold the plywood to the wall.

          • Tony

            Cool cool, The closet wall (as seen in the picture) is almost completely a double sliding closet door (the kind that fold in on themselves) so I would have to hang something in between the separate door panels. Would not covering that door but instead putting those panels that would go there closer to the source/in a different location yield the same effect? If not I might have to do some jury-rigging to get them to hang there (probably run some wire or string through the slits in the closet door panels).

  89. GAURAV BANSAL

    gudmoring Ted,
    pls explain sir that how to make my office building soundproof form the sound of heavy running packing machines installed on the other side of my building which is my factory. The walls of my office are 9″ thick and the window pannels are vaccumised with alluminium fabrications. bt still sitting there feels as if sitting among all those big giants.
    I am planning to do accoustic, the office building with fibre glasswool of 25mm and density is 48kgs or either with the sheets of K-Fonic.
    The dimension of my office is 80ft by 20ft and the height is approx 25ft. The office is sheded with asbestous sheets with heavy iron trusses.

    Will it be a good solution? Pls do suggest.

    • Ted W

      It is very difficult for me to try to make valid recommendations to a situation like this because there are far too many variables and I do not have a clear enough understanding about the nature of the problem. If these packing machines are loud and producing a very low frequency, attaining a large reduction will require a substantial change to the space. Your mention of “glasswool” likely will not block sound due to the reasons explained in the article.

      Sorry I am not able to offer much help. Thanks,
      Ted

  90. Tristan R

    Hi Ted,

    This was very helpful for me, but I’m still debating which is the better choice for my situation.
    My roommate and I live in a 1bd apartment that is split in the middle by two swinging doors that are kept closed. There is an angled gap at the top of one and the bottom of the other, and both have 2 small panes of textured glass in the top 1/3 of the doors. We also have wood floors, so the doors have gaps at the bottoms. It is approximately 60″ wide by 72″ tall to cover all the gaps.

    I can basically hear everything above a pin drop from my roommate’s side, though him not so much from my side. This is a big problem for me because I often get woken up early by him moving around and I’d like to be able to hear my own videos / music without having to put on headphones every time he puts on videos / music.

    I read through your previous comments and am trying to decide between whether I should get the Mass Loaded Vinyl Noise Barrier or a soundproofing curtain. If you have other suggestions I’d be happy to hear those as well.

    • Ted W

      To get right to your question, if this were my living situation I would use the acoustical quilted curtain as long as my budget allowed for it. The advantage of the curtain over the vinyl is twofold. The curtains arrive with a vertical hook & loop seam to attach one panel to the next, which will greatly reduce the amount of sound that could potentially pass through/between the curtains. Additionally, even though the curtains are an industrial-grade product which has its roots and is traditionally used in manufacturing plants and the like, it is much more of a finished product than the vinyl itself. The vinyl is plastic and depending on how the vinyl is made (extruded manufacturing vs. poured manufacturing) it can off-gas (stink) for quite some time. It’s essentially a very thick, plastic shower curtain.

      The cost, however, is going to be quite different. Very roughly, you have about 30 square feet for the door opening. For budgetary purposes, though, let’s assume 40 square feet. Without shipping and/or anything to mount either of the products, the vinyl is going to run you somewhere in the ballpark of $60 and the quilted curtain panels, because there is quite a bit more labor and additional material associated, will run you somewhere around $480.

      Even with either product installed, you will probably need to either continue to use your headphones and/or a very low speaker volume for things like videos and music. This is just the nature of the beast when you have two people living in a one-bedroom apartment. Another thing you might want to consider is a small white noise machine for your sleeping area. This will do an amazing job at helping to hide/mask subtle noises made by your roommate so that you are not woken up as easily. I have two of them myself – one in the bedroom and one for my kids.

      Hopefully this is helpful. Let me know if you have any questions. Thanks,
      Ted

  91. Manuel

    Hi Ted,

    First of all, thank you for your very detailed blog!
    What do you suggest to put behind a TV to reduce the “echo” produced by the fans? I have the TV “inserted” in a sideboard.

    Thank you in advance!

    Regards,

    Manuel.

    • Ted W

      Thanks, I am glad you enjoy the blog!

      There are a few possibilities for the best product to use, and unfortunately I’m not all that familiar with TVs that have fans installed. Additionally, depending on whether this is a front-speaker TV or a rear-speaker TV, it might change the answer to this question.

      I think that the product I would start with would be the Echo Eliminator panels. These are available in small quantities, various colors, is a low-cost product (both for the product and the shipping costs), and it is in stock.

      Let me know if you have any questions. Thanks,
      Ted

  92. goldshel

    Hi Ted,
    I live in a councill block in London which has non-existent sound insulation.
    It has concrete floors and walls with very little in between.
    I have just paid £1,000 for my neighbour above me to buy carpet and underlay and now now want to tackle the sound issue I have with my neighbour next to my hallway and bedroom.
    My neighbours kitchen backs onto one wall of my bedroom and whenever she goes in the kitchen I can hear her opening drawers and cupboards. I can also hear her cutlery in the sink.
    Her kitchen extends from my front door and hallway to my bedroom.
    1. Can I soundproof just the wall in my bedroom or would I have to do the wall in the hallway also?
    2. Can you advise of the most effective way (product) with the least expense to stop the noise coming through the wall and also a more expensive option?
    I would be most grateful for any help as noise pollution is wrecking my life!
    regards,
    Sheldon.

    • Ted W

      This situation is incredibly difficult because of the type of energy/noise you are dealing with. When a drawer or a cupboard closes, it introduces energy into the structure as a vibration. That vibration energy travels from one hard surface to another, kind of like electric current. Unless you decouple, or eliminate, the hard surface to hard surface path that the sound uses it is very, very difficult to reduce the sound of impact as you described.

      I don’t know enough about the wall/construction assembly to try to make solid recommendations but to put some kind of answer together for you, you might want to explore these two products: Green Glue damping compound and RSIC-1 Sound Isolation Clips.

      Thanks,
      Ted

  93. Kristina

    Hi Ted,

    I am concerned about noise in my new veterinary clinic. The clinic is mainly hardwood floors, plaster walls without insulation, and ceiling tiles. Cabinetry is laminate. My office is next to my consulting room, and phone conversations in the office are clearly audible in the consult room. Also, the clinic is noisy in general, when I shut the consult room door or move the chairs, the noise of door latches and chair feet is louder than normal.

    I have put rugs down in the consult room which has reduced echo, and a rubber mat on the stainless table. I was thinking of hiding a product under the wooden seats, under the stainless table, and on top of the cabinetry to reduce echo – what would you recommend – carpet tile, cork, foam? In the office, I am going to lay carpet tiles for echo. There is a 50mm gap between ceiling height and ceiling tiles, what should I fill that with to block sound – timber architrave? And what should I apply to the office wall itself to block sound?

    Thanks for sharing your knowledge, it also makes for very interesting reading.

    Kristina

    • Ted W

      It sounds like there could be a few things going on with your clinic. It also sounds like you may be somewhere outside of the United States, which may make product cost prohibitive for you.

      There are two different things that need to be considered separately – stopping sound from leaving and/or entering each room and the echo/reverberation problems. As I mentioned in the article, blocking sound is done by eliminating common air space and adding mass and density between the two spaces. To block sound from room to room you need weight – the heavier something is the more sound it will block. I would suggest using something like drywall/sheetrock – or some kind of heavy plywood above the ceiling tiles.

      As far as products to control the echo in the space, you want something that is light, soft, and fluffy. Carpet tile might do a little bit of absorption. Foam, depending on the thickness and type, might do a bit more. Cork will not help. Putting panels in hidden locations (under chairs, tables, etc) isn’t ideal, but it will help some. It is better to put these types of panels on exposed, hard surfaces because the sound will be reduced more at a first point of reflection. Imagine putting double-sided tape under the tables and chairs and then throwing a handful of rubber balls toward one of the walls in the space. The balls will eventually bounce and hit under the chairs and tables, but they will hit the walls, the ceiling, and the floor first. It is better to absorb noise as soon as you can, rather than letting it reflect around in the space first.

      I hope you find this helpful.
      Ted

  94. Marianna

    Hello Ted, first of all I wanted to thank you to be willing to help people so much!

    I’m looking for the best solution for my problem. I just moved into a bachelor, there’s only one window in the apt, which is huge, and overlooks the patio. I hear, almost 24/7, a horrible noise (vibration), coming through the wall next to the window. It’s probably the AC of one of my neighbors that I could not identify. We all have a wall AC placed next to the window, our bachelor are all the same. When I lean my ear on the wall I can hear (and feel) the vibration really high. So the noise is mostly the product of the vibration, and the fact that it’s next to the window it makes it even worse. What do you think it would be the best solution for me?

    Thanks a lot

    Marianna

    • Ted W

      There are a few difficulties that you are going to find in this situation. The first is that this is not a unit that you own. The second is the type of energy/sound problem that you are experiencing. If the machine is introducing a physical vibration energy into the structure, the only way to start to reduce that is by putting the machine on some kind of isolator that allows the machine to move and vibrate, but eliminate that energy from getting into the structure. Most of the time, this is done with some kind of spring isolator. There are lots of different types and styles of spring isolators and choosing the right one is very dependent on the situation and the machine itself. If these A/C units are mounted into the wall (rather than a separate unit sitting outside), there isn’t much we can do.

      Additionally, because you do not own the unit, you are probably not able to do any construction to the space. There may be a few products that would offer a small amount of relief for a situation like this, but they are going to involve construction. There are not any easy, low-cost and/or temporary products to help with a problem like this.

      Sorry,
      Ted

  95. Buddy

    If we want to build a small anechoic box, is there a limit to how small the box can be? For example, does it need to be a multiple of the the wavelength of the lowest frequency sound which might be generated?

    • Ted W

      I do not know the answer to your question. I would assume that it would need to be relatively large simply because of the wall construction assembly that needs to be built to block outside noises from readings on the inside of the chamber.

  96. Ana

    I share a 20 foot long wall, with thep people next door, and I’m trying to find out what I can do to block the sound of the door slamming and the music coming from my neightbours, also every time they slam the door the wall vibrates. I have been looking for a.solution and I heem ben running into a wall every time because I get different answers in what works best.

  97. Murf

    Hi Ted.

    Thanks for that informative post. While doing the initial web search that led me to your site, I too thought I needed to make some kind of foam-lined box to block the high-pitched hum coming from an battery inverter I installed recently to overcome the 12-hour-a-day powercuts here in Kathmandu. Reading through your piece though, I now realise that this may well not be the case, as you explain that foam doesn’t, in fact, block sound.

    Given that I’ll be generally limited to what basic materials might be available to me here, I would greatly appreciate whatever advice you could give me regarding what I might use to line (??) the 2.5ft x 2ft x 2ft wooden (most probably 3/4in ply) box I intend making to house this electrical device in an effort to limit the effect of its annoying high pitched hum.

    Many thanks. :o)

    • Ted W

      The heavier the walls of the enclosure, the better. I would suggest using two layers of plywood, or plywood and drywall, or plywood and MDF board. You will also want to put some kind of soft foam (or foam-like) product inside of the box so that the sound being made is absorbed rather than bouncing around until it finds a hole or a place to leak out.

      Hopefully that helps,
      Ted

  98. Anthony Cavill

    Hi Ted,

    Thanks for your blog. Found it fascinating!

    Wondered if you could help with a noise problem caused by a refrigerator.

    I’m in the UK. just bought apartment; the kitchen is next to our main bedroom. On the adjoining wall there is the fridge. Between the fridge and the wall is a 4″ gap, (with a 1″ thick facia panel just at the front so that the gap is not visible from the kitchen).
    Can you recommend what we could place in the gap from above, ie drop down/fix so that it’s between the wall and the fridge? the gap is 6ft x 3ftx 4″ approx.

    Kind regards

    Anthony

  99. David silvia

    We own a salon and in the massage room noise has to be kept to an absolute minimum to create an atmosphere of calm and total relaxation. Problem is voices can be heard from adjoining rooms also beeping from the lazar machine next room over. We don’t own the building so tearing open the walls to insert sound blocking material is not an option. One door no windows . I don’t know weather to attack this problem from inside the room or outside it to prevent the noises from getting in. Seems to me that sound waves hitting the outside walls of this room need to be absorbed before they have a chance to resonate through the sheet rock and into the room. Could you give us some ideas that would keep the noises out ?

    • Ted W

      The situation and limitations that you presented are challenging. I would be happy to discuss this room with you rather than typing, so if you would like to, please feel free to call me (952.466.8225) when you have a few minutes.

      Unfortunately, I don’t have a nice, easy answer for you. There is not a right or wrong, or even a normal way to block sound. Blocking sound is always different from building to building and sometimes room to room. Many times people call me and want to treat a wall, when in fact, it’s the ceiling, the duct work, the door, or some other part of the room that is actually causing the problem – not the wall. Also, unfortunately, soundproofing is done in the assembly of the wall – it’s how the wall/ceiling is built, not a panel that is installed on to one side or the other.

      You are likely going to need to do a bit of construction to block the sound if it is, in fact, coming through the wall. But, most of the time, it’s not the wall. Here are a few questions that I would need answered to start to offer recommendations:

      • Do you have drop ceiling tiles in these rooms?
      • Do the common walls go to the roof deck? Is that joint airtight?
      • Do these rooms share common HVAC ducts? Or is this a plenum return?
      • Do these rooms have solid-core or hollow-core doors?

      Thanks,
      Ted

  100. Julie

    Ted,
    I have been scouring the internet for solutions to a noise problem in my office, Similar to the spa/ massage room situation above. I have 3 massage rooms on one side and a classroom on the other. I was actually trying to tackle the issue this weekend but based on your blog I’m not so sure I’m doing the right thing. It’s a older commercial building I gutted and remodeled. As a DIY I obviously made some poor judgement calls that I’m paying for now. I have drywall ceilings & walls with original wood rafters but metal studs in walls. There’s no insulation between room walls and I have cork floors. I did keep the original doors as they were heavy solid wood doors. I need noise control between rooms but also I have major noise issues when I have class. I was going to knock small holes into walls between studs and blow insulation in then refinish the drywall. Or would be be better to just use green glue and put up another sheet of drywall between massage rooms? For my classroom I was thinking of making some acoustical panels for walls and ceiling to absorb the sound. It seems to bounce off the walls and down hallway to massage rooms. I own the space so I can whatever I want to do I but I’m limited in funds. Suggestions much appreciated & what will give me the best bang for my buck?

    • Ted W

      Can you send me a few pictures of the rooms you are dealing with? A photo of a representative door would help as well.

      I’m looking for things like the type of ceiling and any possible weak links – vents, pipe cut-outs, etc. – between the rooms and pictures are an easy way to get me that information.

      Do the rooms have shared HVAC duct work?

      Please do not waste your time/money on blown-in insulation – there are far superior ways to block sound.

      Thanks,
      Ted

  101. POORNACHANDRAN

    Hi Sir,
    I am Poorna from India. we are doing vmc machine job works. since its mechanical industry our work place to too noisy because of VMC machining.even though all the windows were closed i feel that too much of noise is there while machining which suffers a lots of people near by company.I just want to know how the noise to be arrested within building itself.we are not able to run the machine during night shift…..some of my Frinds told that thermochole or wooden blocks will absorb the sound and reduce the noise outside.please give a right suggestion for me..

    • Ted W

      Unfortunately there are far too many building and infrastructure related variables for me to start to make recommendations for how to reduce this kind of problem. You could potentially build a free-standing room around the machine to try to reduce the sound from getting to the exterior walls of the building. Typically, building a “room within a room” is a relatively effective way to reduce sound transmission. It looks like you read through the blog post, so you know that the more mass and density you add to your wall assembly the weaker the sound will be when it gets to the other side. You also should know that the sound pressure finds the path of least resistance first, which is why any/all gaps and cracks and potential air leaks in the room.

      Sorry I am not able to specifically answer your question, there are simply too many possibilities.

      Thanks,
      Ted

  102. Lisa

    Hi,
    I live in an apartment condo that I own. I hear a lot of impact noises
    from the people in the apartment above mine, things like stomping, walking, thumping, opening cabinets, drawers, doors. What can I do to minimize the volume of the sound that I hear? I just don’t want it to be as loud as it is.
    Thanks.

    • Ted W

      This situation can be relatively complicated and starting to get even a bit of reduction can be quite an involved process. The difficulty here is the fact that it sounds like there is a lot of physical impact noise being introduced into the structure by the people above you. Sometimes, even with significant modifications to the entire floor/ceiling assembly, noise issues are still present. Depending on the engineering of the floor/ceiling assembly and the amount and type of energy that is being introduced, the reduction offered is going to vary.

      For instance, if you have a 400lb person stomping on the floor, you will hear and probably feel it. Also, it is important to keep in mind that your wall studs are screwed into the same floor joists, so you likely have energy coming directly through the ceiling as well as down through the walls.

      The most aggressive approach that we have to offer when treating the sound from downstairs is the RSIC-1 Clip System. These clips float the drywall off of the bottom of the joist – essentially hanging the ceiling on shock absorbers. It requires removing the existing ceiling and re-installing it a few inches lower than it is now.

      The only other product that may offer some reduction is a product called Green Glue. This is a vibration dampening layer that would go between your existing ceiling and a new layer of 5/8″ sheetrock. This is not an adhesive – you will need to screw through the sheetrock and into the joists, but it will dampen the vibration energy of the structure to some degree.

      Unfortunately, most people want an acoustical panel to simply apply to the ceiling. That type of product will not do anything for you.

      Please let me know if you have any questions or if you would like to discuss this further. Thanks,
      Ted

  103. David

    Ted,
    I’m planning to convert my garage to a music studio. I’ve seen many solutions for sound blocking in drywall, but how can I block sound from my 7′ x 16′ / 4-panel wood garage door? The panels appear to be hollow inside. I thought about attaching sound absorption foam, but that will not block sound. Can you recommend any low cost solutions – either attached or unattached to the door?

    Thanks,
    David

    • Ted W

      Unfortunately, there isn’t an easy and cheap way to soundproof a large garage door if you need to continue to use the garage door. If you don’t plan to open and close the door anymore, let me know and I will walk you through a few of the possibilities to see if we can find the best solution and approach for you.

      Thanks,
      Ted

  104. Zack E

    We are locating a call center inside a 38′x150′ concrete block walls, concrete floor and concrete ceiling room. The ceiling is 14′ high. What is the best way to dampen the echoes and sound “liveliness” of this room? Is it better to put foam on the walls or hang down 4′x8′ sheets of double sided foam vertically down the center of the room? The floor is carpeted with 0.250″ thick carpet squares. Thanks.

    • Ted W

      We have a few different ways to take the edge off of the space. Choosing the best and most appropriate is sometimes dictated by the building itself. Does this room have a fire-supression sprinkler system? What is the lighting ike for this space? Do you have any pictures of the room that you could send so I could see it?

      Most of the time, rooms like this have a fire-suppression system where the heads are relatively close to the ceiling deck. That type of system eliminates the possibility of baffles (panels hanging down like flags, perpendicular to the ceiling) or clouds (panels suspended like flying-carpets, parallel to the ceiling). Most of the time, rooms like this need panels mounted directly to the walls or ceilings so that they do not cause a violation of the fire code.

      A room that is 38′×150′×14′ would generally need approximately 2,300-2,400 square feet of treatment to make a good, noticeable reduction in the reverberation time and echo. This would not turn the space into a recording studio, it would, however, be much more tolerable. You might want to take a look at the Echo Eliminator panels which are cost-effective, light, easy to install, in stock, and available in 9 different colors in 2′×4′ panels.

      Thanks,
      Ted

  105. Paul

    Hey Ted:

    We have a basketball hoop in our backyard.
    The other day, our neighbor came over and complained about the sound of the bouncing ball. She claims it disrupts her not only while in she is in her backyard but also in her home.

    Her home’s foundation is about 15′-20′ higher than ours, and we share a block wall that is about 6′ high, but again our home is much lower than hers. Both homes are single-story.

    After reading one of your articles, I’m assuming it is the echo of the bouncing basketball that is bothering her. She was very nice when she spoke with us, so we want to see if there is a win-win solution. I, of course, do not want to prevent the kids from playing ball in their own backyard, and moving the hoop to the front of the house is not a preferred solution. We’ve already thought of “scheduling the basketball”, but that too is not preferred.

    Any ideas? Thanks!
    Paul

    • Ted W

      This situation could be a bit tricky for a few reasons, but I want to make sure I have a solid understanding of the situation before I start to make recommendations. If your kids are out playing basketball, you must be in a climate that is a lot warmer than it is here. It snowed Monday and has been below freezing for the past couple of days. (It’s been a long winter in MN this year…)

      Assuming it’s nice enough to be outside without wearing a full assortment of winter garb, it’s likely that she has her windows open. Is the problem as severe if she closes her windows? Is there a wall-mounted A/C unit in her house facing the court? Do you have the ability to take and send me a few digital photos of the situation – showing the wall and her house? Could you also turn 180-degrees from the direction of her house and take another picture or two?

      The two factors that make this a bit of a challenging situation are the elevation difference between her house and the court as well as the type of noise created when a basketball hits the ground. Typically speaking, if you can see a noise source (if you have a direct line-of-sight with the source) you can hear the noise source. Also, the lower the frequency (bass-type noises) the easier the noises get through whatever you put in front of it.

      Depending on what I see or don’t see in the photos, and depending on what the answers are to the questsions above, my recommendation(s) on how to proceed are likely going to vary. You might want an exterior-grade quilted fiberglass absorber on the concrete walls to reduce the echo and reverberation within the court area. You might also need to extend the fence up, over the top of the concrete wall to block the line-of-sight to her house and install the exterior-grade barrier/absorber on the basketball-court side.

      Hopefully this helps start the conversation and I look forward to hearing back from you. Thanks,
      Ted

  106. Ed

    Hi Ted,
    Thanks for sharing your knowledge. My question has to do with sound absorption. My band rehearses in a studio about 25′ x 25′. The walls are concrete, the floor is wood with a large rug under the drums and it has a suspended ceiling about 9 ft high. I understand that large foam pieces probably will work best but they can be costly. We’d like to keep costs down. Would old clothing/towels/blankets work and if so, what is the best way to utilize them? Are there any other suggestions you might have?

    • Ted W

      If you think about sound as if the sound was water, the physics work relatively the same. Clothes, blankets, sleeping bags, sof things – if it would absorb water, it will absorb sound. If you can keep them spaced off of the structure, they will work a bit better.

      You can also look into cellulose panels – they are cheap and they work will work well.

  107. Jennifer

    My house vibrates and roof,ceiling and items in the house makes popping sounds when heavy trucks
    drive fast. Sometimes I feel the house shaking a bit, like a small earthquake. The house is located on a very busy street.
    1.What are the things I can do to reduce these.
    2.Will there be any damages to structure in the long term.
    3. I built a short wall recently and I feel the noise is coming over the wall right through the window as I feel the noise and vibrations from the heavy trucks right in the house.
    Please help me to solve these issues.
    Thank you

    • Ted W

      Unfortunately I can not help you based on the problem that you described. It sounds like an earth-borne vibration issue. We deal with acoustical panels and airborne noise, not vibration being introduced into the earth which is shaking your structure.

      Sorry and good luck,
      Ted

  108. Ritchie

    Hi Ted

    We are trying to make a sound-booth for the purpose of audiologic testing. We currently have walls with really thin aluminium sheets flanking both sides with almost 9cm thick hard sponge inside. I was thinking of adding on three seperate (0.5inch thick) layer of ply, and a 0.5inch layer of rubber foam or sponge to the existing setup. Will this help in more sound absorption? I could send you pictures of our setup or the materials we intend to use if you need them.

    Your posts are a great help! Thanks

    • Ted W

      It’s really difficult for me to make suggestions without knowing more about the building materials that you are using and I don’t know if pictures are going to better my understanding of what you are building and how. But, think about it this way…

      Imagine there was a flood coming and you wanted to build a dry room. You’re going to build the heaviest walls you can – making them as solid and thick as possible to keep the water pressure out. You’re going to seal all of the gaps and cracks that you can find – so water doesn’t leak in a gap somewhere.

      Blocking sound basically works the same way. Build your walls with as much mass and density as you can. Use heavy building materials like multiple sheets of plywood or cement board. “Really thin” aluminum sheeting doesn’t block any sound because it is lightweight. Rubber may or may not, but it depends on the overall weight.

      I hope this helps, and good luck!
      Ted

  109. Lisa

    Hi. We are going to remodel our unfinished basement. I suffer from migraines and plan to make a “migraine room” What would you suggest to block the sound out? Furnace noise, bathroom noise, lawn mower etc. Walls and ceiling. We’re getting bids this week. What should I ask the contractors? Thanks!

    • Ted W

      Either fortunately or unfortunately there is not a black and white answer to the question you are asking. There are a lot of different answers and things that could be done. I usually explain it like trying to explain the “best” way to build a computer or a car – there are lots of different ways to go about it. There are a few general ideas and best practices to consider so I will do my best to filter out the more extravagant options and run you through what I would do if this were a room I was building. The idea here will be to balance cost and performance.

      When the walls are being framed, I would suggest framing the walls near the structure an inch or two away from the foundation – essentially making free-standing walls. Then, for the other walls, standard framing is fine. I would put standard (cheap and locally available) fiberglass insulation in the wall. When running the ducts to the room, I would increase the size of the duct by 2″ (so, if your HVAC person is running 6″ duct, increase that to 8″ duct) and introduce two 90° bends in all of the supply and return lines. I would then install 1″ Quiet Liner inside of the ducts. This will act like the guts of a car muffler for the airflow noise that would get to the room via the duct system. I would light the room with track lighting or wall sconces rather than cutting holes in the ceiling and using can lights. If you do really want/need can lighting, I can talk about your options later.

      Get a good, heavy, solid-core door for the room. Have your installer put the door into the rough opening like our sound-rated doors go in (you can view the installation instructions). Have them note specifically page 10 – where the door jambe and rough opening are sealed well. I would then seal the door with a heavy-duty door gasket kit.

      So, at this point you have a framed room, door installed, lighting figured out, and the HVAC system taken care of. This is where it gets quite specific. If you have water/waste lines running down through these walls, wrap the lines with Barrier-Decoupler. Anything else unique to the room would need to be addressed then. Does the room have windows?

      As far as the walls and ceiling are concerned, there are a few ways to go. My preferred way to approach the walls and ceiling would be as follows: Attach the RSIC-1 Clip to the face of the studs/joists. These will float the drywall off of the face of the structure. I would then install a first layer of 5/8″ sheetrock on the studs just like rocking the room, with the only difference being that you leave 1/8″ to 1/4″ gap between the walls, ceiling, and floor joints and fill that with a non-hardening acoustical sealant.

      You can always stop there and use the room to assess if the amount of sound blocked is enough for you. Throw out a few sleeping bags in the room so it doesn’t echo like a racquetball court and listen. If you need to increase the amount of sound blocked, you can add a product called Green Glue and a second layer of 5/8″ drywall. Then tape, mud, paint, and finish.

      The acoustics inside of the room are a whole different discussion and there are lots and lots of options there which we can discuss later. Feel free to drop me a reply with questions.

      Thanks,
      Ted

  110. Sergio

    Hi Ted,
    Very informative note.
    I need to build a sound barrier around a very loud machine (hammer mill) located inside a very large industrial building.
    Because of fire codes, I cannot put a roof around the machine unless a separate sprinkler system is located in this new room.

    The room (box) will be approximately 10 ft long by 8 ft wide and as for height, it will need to be at least 12 ft to be above the machine.

    I have a couple of questions: How effective would this roof-less enclosure be due to the open top? I am trying to balance between going crazy with the walls and what noise will come out thru the top.

    The second question is: If this wall enclosure will help, how far above the machine should it reach? I have a 30-foot roof above.

    Thanks in advance.

    Sergio

    • Ted W

      I can certainly appreciate the restrictions that you are considering. An enclosure without a roof will usually reduce quite a bit of overall sound pressure in a building – as long as it’s done correctly. And, it sounds like you are right on track.

      The higher the walls, the better for blocking the sound. I think twelve feet obove the top of the machine is great. I would also suggest putting as much absorptive material on the four walls as you can. If you enclose the hammer mill in a space with hard surfaces, the enclosure is going to act like a megaphone and project the sound toward the ceiling and outward. You could also put absorptive panels onto the ceiling above the enclosed area as well, to stop the sound from echoing off of that hard surface and down toward the floor. If you’d like suggestions for the products for the walls or ceilings, let me know.

      If it’s possible, you could also build the room so that you had the ability/option to add a ceiling later if the open-roof design didn’t get you to where you need to be. There is nothing wrong with starting with the easier/cheaper option and seeing if that meets your needs. You would need the walls anyway…

      I hope that helps,
      Ted

  111. Muj

    Finally a site that explains it like I needed to hear it.

    So we have blockers and absorbers. And I have a car with a very loud stereo. I know that the doors don’t act as good enclosures for my front speakers. I’m assuming I need to use blocking and absorbing, both simultaneously yes?

  112. sal

    Hello
    I am not sure if this is the right site to ask this question, but since you know so much about sound proofing and sound absorbing I’ll give my question a try.
    WHAT TYPE OF ACOUSTIC MATERIAL SHOULD I USE TO SOUNDPROOF OT ABSORB THE ROAD NOISE IN THE CABIN OF MY CAR?

    The road noise in my 2012 Honda Civic is excessively loud. I have covered a layer of dynomat on top of the panel under the rear tires. and on top of the panels, I have added 2-3 inches of liquid foam and filled the rest of he empty space with several inches of denim. In addition, I covered the floor under the carpet and trunk with Dynomat, the rear side panels of my Two door car with filled with denim. I have noticed approximately a 30 percent decrease in road noise. But, the cabin is still LOUD..
    I WAS THINKING ABOUT FILLING THE EMPTY SPACE ON TOP OF THE DIRT GUARD UNDER THE TIRES WITH DENMIN to reduce road noise, what’s your opinion on this

  113. fred

    Hey Ted
    Thanks for the info. The problem I have is I live in a private house that is very old. It was converted into a three family house, I live on the to floor. The neighbors downstairs talk pretty loud. There voice carry into my apt. Through the the floor. I know this because I put my ear to the walls and pretty much hear nothing. But if I go close to the floor I hear the spoken voice seeping through the floor. Once again the house Is old and the floor boards are cracked and spaced. I’m trying to block the sound that is coming into my apartment. I am looking for the cheapest way do so. I’m paying pretty good rent and I don’t think the landlord wants to pay. I’m wondering if putting plywood would help? If so what thickness should I use? Remember I hear everything. But for the most part it’s muffled. But it’s still enough to keep me awake. Thanks, hope you could give me some help.

    • Ted W

      If you think about the sound as if it were water, the understanding of the situation will increase. If you had water leaking up from the floor below, wherever that water could come from is exactly where the sound will come from as well.

      Plywood would likely help because it would block the gaps and cracks in the existing floor. If you could add some sealant between the gaps, that would also help. The only other thing to consider or look for would be the heating/cooling system. If the rooms below share the same ductwork as your apartment does, the sound can also get in that way. If you’re going to use plywood, use a ¾″ thick MDF board – it has more mass and density than standard plywood.

      Situations like this are best fixed with products that are permanently installed, but this may get you bit of reduction without doing any construction.

      Thanks,
      Ted

  114. Isaac Naim

    In my house my laundry room is right next to my room and the sounds frustrates me. Is there any way to make my room quiet and sound proof? Can i put sound canceling pads on the door or what?

    • Ted W

      Answering this type of question is difficult because there are quite a few different potential issues with a situation like this. If the machines are introducing vibration into the structure, it is a much different type of answer than if the machines are just loud. Also, if the laundry room and your room share HVAC ductwork, the sound can very easily be coming through the ducts. The air gaps/cracks around and under the door could also be potential problems.

      Can you critically listen to the space and narrow down the potential weak links in the room? I would suggest putting a small radio in the laundry room and turning it on. Close the door and go into your room and listen. Wherever the music is coming through the loudest is where we need to start. If the music isn’t a problem, it’s probably a vibration issue.

      Don’t bother putting “cancelling pads” or a foam-type product on the door. At least not yet. As I mentioned in the article, foam and “panels” or “pads” don’t block sound – they only reduce echo.

      Thanks,
      Ted

  115. Mary G.

    Hi Ted,
    My bedroom has old single-pane windows and the noise coming from the street below is keeping me up at night, especially buses and trucks. How can I reduce the noise? I am renting so I cannot make any drastic changes. I already installed blackout double-cell cellular shades as well as carpets all over the floor but it doesn’t help much. I was thinking of adding heavy velvet or wool felt curtains but from your explanations above it doesn’t seem it would work?
    Any advice would be much, much appreciated.
    Thank you!

    • Ted W

      The measures that you mention are things that folks do to absorb the echo and reverberation in the room – they are not things used to block sound. If you are trying to block sound, you need to add mass and density between you and the noise source. You need that to be as airtight as possible.

      You would be better with ¾″ MDF board – plywood or sheetrock. You can use simple sticky-back weather-stripping to make the barrier airtight to the structure.

      I will say that “busses” and “trucks” – or anything else that has a low (bass) frequency – are always going to be problematic because of the type of sound that you are trying to block. The lower the frequency, the harder the sound is to block.

      Let me know if you want some product recommendations or if you want to try common building materials first.

      Thanks,
      Ted

  116. Frank

    Hi Ted, I hope you read this, I have a small room and I’m planning to soundproof/lessen the noise of the room for a rehearsal studio for my band. but in my country, materials are very limited and im on a tight budget to purchase online. what other materials will you consider for my project? here’s what im thinking, Im planning of putting thick styrofoam on walls then put carpet on styrofoam? what do you think? thanks!

    • Ted W

      Are you trying to block sound or reduce the echo in the room? Don’t use styrofoam, it is acoustically invisible.

      Let me know the goal and I will do my best to help.

  117. Jorge O.

    “Foam absorbs echo” ? What does that even mean? Echo = a discrete sound reflection, right? So foam selectively transduces (part of) only sound reflections? How can you even tell what’s a reflection and what an “original” without knowledge? I don’t think foam has knowledge…

    I’ll keep reading because I’m interested in the topic but that was not a great start. Sarcasm aside maybe a clarification of terms in the article would be beneficial, otherwise common misconceptions may be just being replaced by new ones.

      • Ted W

        There is a strong possibility that I have something to learn here. Can you further explain what you mean by that statement?

    • Ted W

      The goal of the article is to offer the general public a basic understanding of which products reduce the echo and reverberation time in the room and which products reduce sound transmission from one room to the other.

      If you would like an in-depth explanation of the physics of acoustics, you might be better served by a formal acoustics class. The goal here is to simplify things so that the general public has a basic understanding of sound, and how different products work.

      • Jorge O.

        You’re the expert here.

        I get the point of saying “foam absorbs echo” as a way to clearly differentiate soft material that reflects little sound from heavy material that (almost) completely blocks sound from passing. But I think really both materials are absorbing or blocking all sound, not just reflections, and this could potentially be measured in terms of attenuation of sound intensity.

        You’re right though, getting into more technical acoustic definitions here may hurt the point of your article. I just don’t agree that “foam absorbs echo” (exclusively) I hope the statement doesn’t confuse anyone.

        Thanks for the article!

  118. Chris

    I just built an aquarium in a cabinet, complete closed in with doors. With the doors closed, the aquarium equipment is making too much noise. I want to reduce the amount of noise coming out of the cabinet…any suggestions?
    I thought about buying the studio foam (one with ridges or egg crate) and lining the inside of the cabinet. Will this be a good solution? I think you said this is an absorption not a soundproofing strategy. I don’t need it completely quite, just need the sound reduced by say 50%. Thank you.?

    • Ted W

      Your initial thought about lining the inside of the cabinet is definitely a good starting point. I would get something in there and take a step back and listen. You may want to look into a cut-piece of our 1″ or 2″ Quiet Liner. This could be a more economical option than foam and will possibly outperform foam.

      If it is still an issue, use some weather stripping and seal up the joint between the doors and the cabinet to try to make them airtight.

      Hope that helps!
      Ted

  119. Mo

    I live in basement of my parent house that has drop selling and have a 5 year and a 1 year old children. I am completely tired of my parent running down every time anything happen to see why my kids are crying. what suggestion do you have for me to help my noise not be heard upstairs?
    Thank you Mo.

    • Ted W

      Soundproofing drop ceilings can be difficult – especially when the downstairs and upstairs share common HVAC duct work.

      I would back the ceiling tiles with 5/8″ sheetrock as a first step. I would also get up into the ducts that supply air to the downstairs room. If at all possible, increase the duct size, for example, from a 6″ round duct to an 7″ round duct and introduce a minimum of one 90° bend per supply and return line. I would then line the inside of the ducts with our 1″ Quiet Liner and close the system. That should significantly reduce the amount of sound that is heard upstairs.

      Thanks,
      Ted

  120. Scott

    Greetings Ted,

    Previously I’ve seen a home theatre/gaming setup with the bass drivers set into a platform under the couch. The basic platform was made of 2×4′s and 1/2″ plywood approximately the same size as the base of the couch and about 4″ high, so basically a big speaker box for the subs, pointing up to the bottom of the couch.

    How could a similar platform be constructed for an upper floor room to minimise the amount of sound conducted through the floor to other rooms below? I would want to either keep it low (in the 4″ range) or make the base big enough for people sitting on the couch to use the platform as a rest/floor.

    Cheers. :)

    • Ted W

      To be very straightforward, the answer to this question about how to build a subwoofer box that will minimize the sound that gets through the floor and the spaces below is – it can’t be accomplished.

      If you have a subwoofer upstairs and it is loud enough to be enjoyed, it’s going to be heard – and proably felt – downstairs. That’s just the nature of the beast when it comes to low frequencies. If someone has a subwoofer in their car, you can hear and maybe feel it a quarter mile away. If you put that same subwoofer within 20-30′ of someone, it would take a floor/ceiling assembly that was 5-8′ thick to start to reduce those types of noises.

      Sorry, but that is a really challenging situation. I would suggest a really good pair of headphones.

      Thanks,
      Ted

      • Scott

        Hi Ted,

        Many thanks for the quick reply. Your answer is what I was afraid of. :/

        The previous versions I’ve seen were all on ground floors (ie concrete slabs) where there weren’t any worries about noise, or in homes with dedicated home theatre rooms with full insulation and (usually) few/no other people around when the room was in use.

        I was thinking about something that could be used in a multi-family building environment, but alas. Headphones work for as many people as there are jacks, but not so much for a group.

        Back to the drawing board…and maybe a judicious use of scheduling and volume control when others are around. :)

        Many thanks,

        Scott

  121. Lewis

    Hi Ted,

    When I build my apartment, I put sonopan sheets under the sheetrock to prevent sound from going to the other apartment. Unfortunately that’s not enough. Even when speaking at normal levels, the neighbors can hear. We have a large picture on the wall, can I add sound absorbing panels behind it to reduce the amount of noise transferred to the other apartment? (I want to keep the noise in the room)

    • Ted W

      Soundproofing only part of the wall will not offer you any reduction. Sound pressure finds the path of least resistance. So in your case, the sound would just go around the picture. You would need to add a layer of drywall or do some construction to the common wall. We have a few different ways to do that, but in apartments or other rental spaces, doing construction isn’t usually an option. If you would like my recommendations on any of those, just let me know.

      Thanks,
      Ted

  122. raj shekhar

    I have a 10feet x20 feet Closed Hall (Double door) but there is lot of echo in the room. I want to use this room as a indoor video recording studio. Pls suggess me…

    • Ted W

      I would be happy to start to make some recommendations, but I need to get quite a bit more information from you. Could you please send me some photos of the space as well as the height of the room? Your address or location would help in determining costs, as well. “Recording Studio” acoustics are often much more of a specific approach than just “reducing the echo” in the room, and like people, most studios are unique and should be approached as such. What may work well (or be the best recommendation) in this studio might be the wrong product for that studio.

      Thanks,
      Ted

  123. Louise

    Hello,
    I’m considering a lease for an indoor cycling studio and I’m interested in your recommendations for sound proofing. The space is on the second floor of a 2 story commercial building consisting of a large area which we would break into a studio and a lobby. We ran a test blasting a boom box and you can hear noise below. Faint, though you can definitely hear it when it’s quiet. I have an excellent contractor I’m working with but I also wanted to ask your opinion on how best to sound proof. This is a very good location so I’m willing to pay for high quality, effective materials. We would be renovating the space and would therefore have the opportunity to construct whatever is needed.

    The studio space is ~850 sq feet, there will be up to 35 bikes. The lobby is 350 sq ft.

    As part of the solution I would be interested in controlling the room for reverberation, but first and foremost the main issue is soundproofing. Thank you very much!

    • Ted W

      It’s going to be best if you and I spend a few minutes on the phone to discuss this one. At this point, I can’t tell if you are looking to stop an impact-type noise or airborne-type noise from music being played (or both).

      Thanks,
      Ted

  124. patricia

    hello,
    I have a big problem with pump, fan and a high pitch noise all which penetrate from outside of my fifth floor apartment into the open space within. Although i am on the firth floor i am surrounded by the outside walls of close buildings. There are 5 floors above me. I do not have a balcony but can get out of my window and stand on the floor which joins all of these buildings together. To illustrate essentially i am in a valley of walls (my apartment is the only one like this as the others look out to sky and city). The building in front of me which is 2 yards from my window is the projection room of a theatre. and above that is the roof of the theatre. The noise comes from within the building not on the roof where the big industrial airconditoning units are. The noise particularly from the pump vibrates through the thick concrete wall, floor and thin window glass into my ears and makes me fell nauseous, cant sleep at night and gives me anxiety. Can you help me as it is all driving me mad as it is a 24/7 thing but the pump is constant but ranges in loudness depending on how it is laboring.. The noises are similar to refrigeration noise but on an industrial scale. Cant wait to hear from you.
    Regards Patricia

    • Ted W

      The cheapest and easiest fix would be to just move. Reducing sound – especially from structure-borne vibration energy – can be extremely involved. Essentially, you have to get whatever machine is running and causing the vibration onto spring isolators so that is allowed to move without introducing the energy into the structure.

      You might get some reduction of the airborne sound coming into your apartment by installing a Climate Seal Window Insert over your existing window.

      This just sounds like a very bad living situation with a lot of different things going on – and as a practical approach, finding a space that has problems/issues that are more manageable will be the best, easiest, and cheapest way to proceed.

      Thanks,
      Ted

  125. Lin

    Hello,
    Thank you for your article.
    I just moved in to a new apartment and the first night I was awakended by the huge noise from four A/C units below my window (I’m on second floor and they are on ground). The sound is likely to be caused by the vibration of those machines and it’s sort of like the roar of car engine. I was greatly affected by this noise and I can’t get to sleep ecery night. I’m also thinking of using soundproof material to block the noise and I have tried thick curtain, which doesn’t work at all. I see lots of soundproof material online but I’m really not sure which one is more effective for my situation. I have read your article and thought it to be really helpful. So I’m asking for some advise from you about how should I block the noise outside my window?( my window is 6ft*6ft and four A/C units are right below my window)
    Really thank you for your attention!

    • Ted W

      Are these machines introducing a structure-borne vibration energy into the building, or is the airborne sound causing your windows to vibrate? Have you discussed the problem with the landlord? The most effective way to reduce the noise is to get some kind of line-of-sight enclosure around the machines – but this treatment is intended to reduce airborne noise. Structure-borne vibration is a whole different story.

      Thanks,
      Ted

  126. John Chang

    Hi, I got a pair of speakers & when place at one end of the right corner wall, the bass is louder then the left when it is against a normal wall & close to an opening door. I did move the right speaker out a bit but the bass is bloomy. Can I put some thing on the side or cover with sound absorbing & proofing (I don’t mind covering it up) on the right speaker so that it can minimize the reflected sound ?

  127. Fritz Groszkruger

    We are getting a new fridge because our old one is too noisy and we will use it in the garage. The new fridge will go in an alcove which is plywood on one side and cabinets above and on the other side. Line the space with absorbing material? How about the hardwood floor?

    By the way, the ASI page on “quiet liner” has a typo, “Excellent Noise Absortion.”
    Thought you’d like to know.

    • Ted W

      Thanks for catching the typo. We’ve fixed it now.

      I would use the Quiet Liner to line the three walls of the alcove. You shouldn’t need to cover the hardwood floor.

      Thanks,
      Ted

  128. Jodie

    Hello,

    I live in an old Victorian terraced house in London and have been told by our neighbours that they can hear “normal level conversation” through our walls – in some patches more than others, and perhaps where fireplaces once were (we believe the original fireplaces were removed many years ago).

    The strange thing is, we can barely hear anything from our side – just the occasional bit of loud TV and raised voices if and when the neighbours shout. My first question therefore is – are my neighbours overly sensitive?! We keep our voices down and are generally quiet – but apparently we can still be heard when just chatting in our bedroom (not a very relaxing thought). On the other hand, we can hardly hear a thing… Is it possible for the sound travel to only be problematic in one direction?!

    The neighbours have asked us (a few times) if we would consider sound proofing. We have looked in to it, but it sounds relatively costly and invasive (we could need to strip of skirting boards, coving and repaint etc). Is there anything else we could do? I wondered about acoustic panels but now understand they are for something else entirely (v useful blog post!).

    Alternatively, I kind of feel like if we can’t hear any noise from next door, then the onus really should be on our neighbours to fix the “problem” from their side… Why should we pay to fix a problem we’re not experiencing?!

    Would really appreciate your technical insight into the issue – specifically, how can it be that they’re experiencing something we’re not through the same wall?!

    Many thanks,

    • Ted W

      I’m sorry to hear you are having noise issues. It is impossible for me to speculate about your neighbor’s sensitivity, but you could be correct. They may be very quiet people living in a very quiet space, so even slight noises could be heard easily by them. Sound travel is not one-directional – if sound can leak from “room A” to “room B”, it can equally leak back from “B” to “A” – the difference, however, would be the ambient noise (background noise) difference in the rooms and the listener’s sensitivity to sound.

      Blocking or reducing sound from one space to another is something that is very very specific to the construction of the building. It is very difficult for me to try to make valid recommendations without knowing exactly where the sound is leaking. I would suggest getting together with your neighbors and putting a constant noise source (like a radio) in each particular room on your side (one room at a time) and going to your neighbor’s place and listening. Your ear should be able to tell you where the sound is the strongest (and the leak is the worst) and depending on the details there, you could make appropriate changes to the space.

      Sorry I am not able to offer steps to fix or reduce the problem, I simply don’t have enough information to make recommendations.

      Thanks,
      Ted

  129. Jay G

    Hi Ted,

    Thanks for the blog!

    I have a basement area that will be soundproof (walls, ceiling, floor), except for a stairwell.

    There is a big, heavy door at the top of the stairwell. I’m pretty sure if I make it airtight, that will cut down the sound, but I’d like to do more, if possible.

    If I add sound absorption panels along that stairwell, will it reduce sound to the rest of the house, by absorbing it before it gets there? I know the sound has to reverberate up the stairwell because there is no line-of-sight from the top of the stairway to the source of sound.

    I know this is not perfect, but will panels help at all? If so, where should I focus? One wall and the ceiling? The corners? Spots in the stairwell where I can see the source of sound?

    Thanks again!

    Jay

    • Ted W

      There is nothing wrong with sealing up the door at the top of the stairs and stepping back and listening to asses the need. You could always come back and add panels in the stairway if you experienced a lot of sound pressure in the stairway and had more sound than you want leaking out of the door at the top.

      Installing sound panels in the stairway is simply going to reduce the echo/reverberation/sound pressure in the area. This is likely to yield less sound on the other side of the door, but the door and seals will be doing most of the work. Placement of the panels in the stairwell isn’t as critical as the overall square footage installed and the thickness of the panels – relative to the nature of the problem. Sound simply travels too quickly for the location of the panels to make an overall difference of the echo/reverberation – so if it looks better to have the panels on the ceiling, go for it. If you prefer them on the walls – awesome.

      Please let me know if you have any further questions. Thanks,
      Ted

  130. Leslie

    I have a small problem in that my Blendtec blender is waking my neighbor when I make my daily breakfast. Is there something out there that I can use to absorb the noise? I am thinking about making a box to encase the blender when it is on. Or if you have any other suggestions I am game to here them and try it.

    • Ted W

      This is a bit of a unique request. I don’t use blenders, myself, but I can make some speculations that should help.

      I would start by putting the blender on our Super W pads to absorb the vibration energy of the blender from getting into the counter.

      If the airborne sound of the blender running is also a problem, you could build a box out of plywood or MDF board and line the inside of the box with an absorbent material. There are quite a few different options for what to use on the noisy side of the box. The most effective would be the Echo Eliminator panels.

      Thanks,
      Ted

  131. Meghan

    Hi Ted, Thanks for this post. It’s very informative! We have a situation where our water softener in our garage is on the other side of a bedroom that our newborn is going into. If he’s anything like our daughter he’ll be very sensitive to sound. Even with a white noise machine in the bedroom you can hear when the water softener is regenerating, not to mention when we operate the garage door. If I understand what you wrote here, the sound BLOCKING materials is what we need. With all the plumbing in this shared wall, we cannot redo it to make it a true soundproof wall. If the vinyl barrier was hung on the shared wall in the garage, how significantly would it block the noise into the bedroom? Would foam/sound absorbing materials do any good?
    Thank you!
    Meghan

  132. David Leibowitz

    Hi Ted,
    Would appreciator your advice.
    i have soundproofed a small outside spare room by drywall false ceiling and insulation material between concrete wall and drywall and i’m happy wight he result.

    How sound I treat the floor , tick pile carpets or rather spend the money on tick rubber etc under felt? Many Thanks
    David

  133. Maia

    Hi Ted,

    when we bought our little apartment, there was no noise coming from our upstairs neighbors. It turned out that they were supposed to move in 2 months after us. Now, our living conditions are unbearable. We can hear them go about their business as if there were no ceiling! They wake us up when they get up and go to the bathroom barefoot. You can only imagine what it is like when they put on their shoes or invite some friends or have sex.

    We’re stuck as we can’t sell it for another two and a half years. And to be honest,we wouldn’t want to have to lie to our potential buyers the way we were lied to by the former owner.

    What can we do with our ceiling to stop the noise or at least bring it to the bearable level?
    We live on the 4th floor, which used to be the last one. But, at certain point someone got the permit to buy the attic of the building (we live in France and those old buildigs come from 19030′s) and make 3 apartments there.

    Thanx!!!

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