Tag Archive: absorbing

  1. Soundproofing vs Sound Absorbing – What’s the Difference?


    Soundproofing vs sound absorbing – explaining the difference.

    When someone has a noise problem and doesn’t know what to do, who to contact, or how to begin, they often turn to the internet and search for terms like “soundproofing.” We have been fielding calls from people looking to solve sound problems for years. These callers often explain 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 start with a conversation about the room itself, the use of the room and the type of noise that we are dealing with in each particular situation.

    (Download your free guide: Solutions to Common Noise Problems)

    It is common for people to ask for pricing on soundproofing foam,sound-absorbing foam, soundproofing insulation, or soundproofing panels. They are sure that foam is the ticket because they have seen “egg crate” foam or other similar products as finish wall treatments in recording studios, on TV shows, and in movies – and these types of rooms are really quiet or legitimately soundproof.  So, it stands to reason that panels block sound, right? Well, not exactly… This misconception is incredibly common – so if you are reading this thinking to yourself, “So, does sound-absorbing foam work? Isn’t foam used for soundproofing a room?” Unfortunately not. Foam doesn’t stop a sound, it absorbs or reduces echo within the room. Don’t feel bad. Plenty of people thought the same thing. Luckily, we are here to save the day. Soundproofing vs sound absorbing – what is the difference?

    Soundproofing vs sound-absorbing

    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/reduce sound transmission. (There are some panels that will do a bit of both. These are generally called composites, but for now, let’s keep it simple.) Echo absorbing materials are used to improve the sound quality inside of the room in which they are installed.  They are usually installed on the walls or ceiling as a finished surface in the room. Products that are used to block sound are used INSIDE of the wall or ceiling – as part of the construction material. They can be dense, heavy materials or materials that will decouple the wall assembly – and due to their density, often reflect the sound back into the room rather than the sound penetrating through to the other side. Absorbing the echo in a room and blocking or reducing sound are done in two very different ways and with different products and approaches.

    You Can’t Build an Aquarium With Sponges

    Here is a simple analogy that helps people understand the physics of sound and how it works.   Imagine you are building an aquarium to hold water. Would you use glass panels or sponges for the walls of the tank? This is clearly a ridiculous question, but it paints a picture of simple physics that applies here.  Sound acts very similar to water when you are trying to control it. If you used sponges as the walls, they would absorb the water but quickly let all of it seep through to the other side. Glass and good seals block the water and keep it in place. Acoustical materials made from soft, squishy things like sponges are going to absorb. Dense, heavy, air-tight materials will block. Those are the basics right there. Now you can impress your friends with your newfound knowledge. Let’s dive more into the specifics of soundproofing vs sound-absorbing.

    Absorbing Noise

    Sound Absorbing Options

    In fact, some people “soundproofing” a room on the cheap side even hang moving blankets on the wall to create a DIY sound-absorbing panel. If you are interested in a more professional or finished look as well as performance, there are fantastic sound-absorbing products on the market.

    Sound Blocking Options

    For years, I’ve used mental images and analogies to help people realize that they already understand the physics of sound, they just don’t know it yet.  When they (or you) can visualize and relate to an idea you already know, everything makes more sense. So, here is another one. Imagine 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, you decide you are going to put 2″ thick “egg crate” foam onto the studs. Keep in mind this foam has almost no mass or density.  It’s light and soft, and it is mostly air. After you’ve installed this sound absorption material, you tell your friend to go stand on the opposite side of the wall and begin talking. Regardless of the type or thickness of foam used, you will be able to clearly hear your friend as if there were no wall in front of you. Why? Sound travels through the air. Because the foam is mostly air (it’s light – weighing very little), sound travels through it.  Just like water traveling through the sponge.

    What materials can or do block sound? Products that are designed to block sound from entering or leaving a space are almost always found inside the wall construction or are part of the wall itself.  There are three basic ways to block sound: Add/increase the mass and density (weight) of the wall to simply make it heavier, decouple the wall assembly (where one side of the wall doesn’t touch the other) or dampen the vibration energy of the wall.

    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 friend to the other side again and have them start talking. I would be willing to bet that you cannot hear much of what they are saying because you have added so much mass to the wall. If you are looking at adding some sound-blocking materials to your room, here are a few products to consider:

    • Soundbreak XP soundproof sheetrock – sound deadening drywall used in the construction of high STC (Sound Transmission Class) wall assemblies.
    • Mass Loaded Vinyl Barrier (MLVB) – an acoustical barrier made from high-density limp mass barrier material to reduce noise transmission.
    • RSIC-1 Clips (resilient sound isolation clips) – prevent sound from noisy neighbors from transmitting through your walls or floor/ceiling assemblies.
    • Green Glue vibration dampening compound – sandwich this between two layers of sheetrock to greatly dampen the vibration energy through the wall.


    You guessed it, I’ve got another analogy! Let’s head to the gym. It’s currently under construction because they are adding a few new racquetball courts. Let’s check them out. The room is made out of concrete and because it’s a regulation-size racquetball court, it measures 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, and 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 off any hard surface but will be absorbed by a soft surface.

    Now what?

    If you made it this far, I congratulate you for sticking with me 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 who 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 issues.

    Of course, you aren’t officially 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. Talking to an expert will help you better understand the way sound moves in your room. He or she will also know enough about the products to point you in the right direction. So, before talking with that person, I would have these questions answered:

    • Are you looking to block sound or absorb echo? Now when you understand soundproofing vs sound-absorbing difference…
    • What are the dimensions of the hard surfaces in your room?
    • What is the room used for, what types of sound are you looking to block/absorb? (a high pitch-squeaky sound, voices, music, children, low frequency-bass type sound, all of the above…)
    • What are your ideas as to the best way to treat the room, where to put the product, or how to approach the situation?
    • What type of aesthetics, finish or colors are you looking for? 
    • Are aesthetics important, or do we need to do this on a tight budget?

    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. Knowing the answers to all these questions will give the expert all the things they need to diagnose the noise problem and offer useful solutions. No matter what size and shape your room is, there is a perfect combination of sound-absorbing and sound-blocking materials to make it a great sanctuary from the sound. Whether you need Soundbreak XP soundproof sheetrock, sound-absorbing panels, sound isolation clips, or some combination of products, talking to an expert will help you make the right choice, the first time.

  2. “Noise is the No. 1 Quality-of-Life Complaint in NYC” solutions from Acoustical Surfaces


    An article came out earlier this year titled “Noise is No. 1 Quality-of-Life Complaint in NYC” by Verena Dobnik, and I wanted to contribute some basic solutions for noise reduction to mitigate some of the complaints listed in the article. (http://bigstory.ap.org/article/noise-no-1-quality-life-complaint-nyc)

    Large cities with large populations and lots of concrete are always going to be noisy, that’s just part of the game when it comes to living in the city.  If you don’t like noise, it’s probably not the right place for you.  But, even in a big city, people should be able to create quiet, comfortable spaces to unwind.  Fortunately there are quite a few different products that can be used to reduce the amount of sound coming into a building.

    RSIC-1 Clips
    RSIC-1 clips can be used for exterior walls to float the drywall off of the studs, allowing the sound pressure to be converted to heat by allowing the wall assembly to vibrate:

    Green Glue
    Green Glue and an additional layer of 5/8” drywall can be used to retro-fit an exterior wall to increase the STC rating of the assembly, and block more sound from making its way into the space:

    Acoustic Window Inserts in Historic Building
    Climate-Seal Window Inserts are a very effective, retro-fit way to reduce the amount of sound coming in a weak window.  These windows snap into place and are held onto a metal frame that is installed around a window:

    Noise Barrier/Sound Absorber Sound Blanket
    Exterior Grade Quilted Barrier-blankets can be used around noise sources outside such as: Generators, AC Units, etc.

    These are just a few different materials that can be used to reduce the amount of sound inside of buildings. Find all of our materials at our home page www.acousticalsurfaces.com


  3. Church Acoustics in Fellowship Halls


    Fellowship Halls & Multi-Purpose Rooms

    Echo Eliminator Recycled Cotton Acoustical PanelsChurch acoustics in fellowship halls or multi-purpose rooms are some of the more frequent rooms that we are asked for recommendations for acoustical treatment. These rooms have a few very common similarities that are the reason for the need for acoustical wall panels or acoustical ceiling panels. These rooms are often quite large so that a large number of people can use the room at the same time. They also commonly have cinder block or sheetrock walls, a vinyl tile or linoleum floor. If carpet is present, it is almost always a very low pile, industrial carpet.

    How Many Panels Do I Need?

    As far as echo and reverberation are concerned, the larger the room, the more square footage of acoustical treatment is needed to get the proper level noise control. Over the last few years, I have talked to thousands of people and a series of the same questions continues to be asked. “How many panels do I need?” This is a simple question that needs to be asked. The answer, however, is not as simple because rooms and the needs of rooms are always different. For simplicity’s sake, I know that rooms like this don’t need “recording studio” sound quality. They do need a noise control solution that takes the edge off so that when the room is filled with people the noise level is not ear splitting.

    I’ve come up with a very simple equation to start with to answer the question above. This is not a guarantee or a necessity, but it is a generalization that I have had an extremely high success rate with. The square footage of paneling generally needed is found by multiplying the cubic volume of the room by 3%.

    Height × Width × Depth × (.03) = Square Footage Needed For Room

    What Kind of Treatment Is Best For Me?

    Again, there is not a right or wrong answer to this question but there are some tendencies or trend that I do want to explain. Although there are hundreds of different kinds of acoustical treatments (including wall panels, ceiling panels, cloud baffles, diffusers, etc.), when it comes to treating a room like this, this extensive list of options is just about always reduced to two different types of panels. These are our Decorative Fabric Wrapped Fiberglass Panels and our Echo Eliminator Panels.

    Fabric Wrapped Fiberglass Panels – Edge OptionsThe Fabric Wrapped Panels are custom made boards of fiberglass that are cut to size and wrapped with a decorative fabric. This option offers the most freedom of panel size and color which is very attractive to quiet a few people. The unfortunate part about the product is that because it is custom made and made by hand, it also comes with a higher price tag. This price tag often makes this option less attractive or simply not an option. Especially for a multi-purpose room where aesthetics isn’t as critical as it would be in a room like a sanctuary, our Echo Eliminator recycled cotton panels become much more attractive.

    Echo Eliminator Cotton Acoustical PanelsThese acoustical panels are made from recycled cotton fiber and we offer them in nine different colors. They have an absorption rating that makes them an extremely efficient acoustical treatment. Because they are made from a recycled material, they are also very cost effective. They can be used as wall panels or ceiling panels and are most often glued directly to the structure with a construction adhesive and a contact adhesive. They are Class A fire rated, which is always important as well.

    Where Should I Put These Panels?

    My answer to this question almost always surprises people. For all practical purposes, to take the edge off of a room, the exact location of the acoustical wall panels or ceiling panels does not matter nearly as much as the square footage of panels introduced into the room. This leaves the end user with a lot of freedom to put the panels in a location where they will be most discreet.

    The only two recommendations that I would like to pass along would be to space the panels out as evenly as possible throughout the room and, if the aesthetic works, space the panels out (rather than installing them one next to the other). Installing them throughout the room will give you the most even acoustical result and by spacing them apart, you will effectively increase the overall surface area of absorption and increase the performance of the panels as a whole.

    Echo Eliminator in Zig Zag Pattern

    Success Story

    In December of 2006, Dennis contacted me about the multi-purpose room at the Bon Air Church of the Nazarene in Kokomo, Indiana. He was collecting information about products and treatments for the room. We talked briefly about the room and a few of the more popular products that he might be interested in and I put some samples and literature together and sent them to him. We spoke about the advantages and disadvantages of the products and he took the information to the committees and decision makers of the church.

    Like all projects that I have done with houses of worship, the project was discussed and questions were asked, and ultimately the Echo Eliminator panels were chosen due to the low cost of the product and the high absorption numbers. Dennis sent me the measurements of the room and based on the size of the room and the surface that were present, I used the following equation to help him start to figure out how many panels the church was going to need.

    The Room

    This multipurpose room measures roughly 55′ × 65′ and has 20′ ceilings. The equation that I used to determine the square footage needed is listed above.

    55′ × 65′ × 20′ = 71,500 (cubic feet) × .03 = 2,145 Square Feet of Panels

    The Solution

    Echo Eliminator Recycled Cotton Acoustical PanelsBased on the numbers from above, Dennis worked with church members to come up with a unique and decorative pattern for the cotton panels. The church purchased 64 panels of the Light Gray, 110 panels of the Pure Blue and 20 panels of the Navy Blue. They also purchased the cutting blade to cut the 2′ × 4′ panels down as needed.

    Most of our panels are adhered to the walls or ceiling of a room, but this type of installation is very permanent. Although most people are never going to want the echo problem to return, the idea of using a construction adhesive to install the cotton panels isn’t ideal. In this case, the installers used small nails to hang the panels. I do not know the exact details of how it was done, but they pulled it off very well.


    We have installed our sound panels. I have attached a picture to show you the pattern we chose. I will be sending the saw blade back to you tomorrow. We have seen a significant reduction in echo, and we especially can understand speech much clearer.

    We used nails to put up the panels. The color consistency was good, and they look good in this application. I would be interested in your thoughts.

    Pastor Dennis R.