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

Thanks for the comment. Is there any chance you would have time to take a few pictures and send them my way? A visual representation of the situation would give me a much better position to do my best to make some recommendations on how to fix this for you.

The product that I have had the largest success with over the years is the Reinforced Exterior Grade Sound Blankets. These are essentially custom-made blankets where we quilt a nominally 2″ thick fiberglass (absorber) layer to a 1lb per square foot Mass Loaded Vinyl (sound barrier). These blankets are made with grommets to be used as points of attachment as well as vertical Velcro seams to attach one panel to the one next to it. Because they are made on a per-job basis, I would need an idea of the dimensions in order to determine a cost.

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

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.

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

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?

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

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.

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)

Thanks.

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!

Unfortunately there really isn’t an ideal fix/solution when it comes to rooms that have walls that do not go all the way to the roof deck. A drop-ceiling tile situation is an extremely difficult place to start when you are trying to block/contain sound transmission from room to room. It is, however, a necessary evil when it comes to building design and construction.

I would suggest extending the wall 6-10″ above the ceiling grid and using a thin, foam-core tape between the drywall and the perimeter angle of the t-bar grid. Some have also used a non-hardening construction sealant on the plenum side of this joint if the thing foam-core tape is not readily available. Install standard office-type ceiling tiles and back each with a piece of either 1/2″ or 5/8″ drywall. Depending on the type of HVAC system, you may pick up a few additional points by installing a layer of an absorptive surface, 1″ Quiet Liner or some type of fiberglass insulation, on the back side of the drywall. This will prevent the sound that does get into the plenum from reflecting from the deck to the drywall and back again.

The other factors that you might want to consider are the lights and the HVAC system. Many times, the HVAC system is a plenum return and if this is the case it is common to put a 90° section of duct on the back of each return register and line this duct section with an absorptive surface like the Quiet Liner mentioned above. Point these boots away from each other if possible. Depending on the style of lighting, many people have made boxes in the plenum using the Echo Eliminator 8lb Composite. These panels can be used to block sound, but will also reduce the air exchange rate that some lighting systems use to cool themselves.

I hope you find this information helpful. Please let me know if you have more questions or need any more information.

Thanks,
Ted

What is a good architectural detail for the wall to ceiling intersection in office/medical exam rooms where the walls are drywall (with resilient channel) but the ceilings tee bar with drop in 2X4′ acoustical tile? How higher than the ceilings must the wall assembly go and how does the fiberglass go over tee bars?

Don

In general, you are correct – standard privacy fence products are not likely to reduce much sound assuming there is not a visual barrier between you and these units. A baseball back stop angle at the top of the fence will allow for a bit of that, but unfortunately I don’t have any pictures of one of these style of fences installed. I am normally working directly with contractors who are focused on building the fence, installing the panels and moving onto their next job as quickly as they can. Even partial roof sections limit the airflow that the machines need to operate properly.

I would assume you could contact your city office or township office and get the contact information for someone who can provide you with city ordinances. Other than that, I don’t know.

Best of luck to you. Let me know if you have any more questions.

Thanks,
Ted