Soundproofing Myths You Should Know About! Save time by avoiding these common soundproofing errors! The video shows swatches of carpet “soundproofing” the room!” As a service to those doing their own analysis, noise control planning and sound proofing, we’ve prepared this list of Don’t. We can’t explore every aspect of doing a good soundproofing job, but avoiding certain materials and processes can save you lots of time and money. Don’t waste time and money on ineffectiveness. If you have lots of time and wish to experiment with different techniques and unknown materials, please do so! (and let us know how it comes out!). Many people have made the errors mentioned here and some have been kind enough to pass them on to us for inclusion. Please feel free to contribute! If you have anything but a simple problem and the solution isn’t obvious, get help! No need to figure this out all by yourself, it’s too easy to make expensive mistakes.
There ARE many experts doing work in this field. Most states require them to be licensed. You can find help in the local yellow pages under “Acoustics” or check with your local building code department or state contractors license board. For a contractor to work under your direction, locate one using the contractor locater service, such as ““, listed at the bottom of our pages. At least read everything on this site and better, get the we sell here.Unless you have time and money to waste: DON’T experiment! We’ll help you- call us! Or we’ll even call you! Read up on other’s experiences: see the sidebar for the “FORUM”. Maybe your situation has been dealt with there! Some materials to avoid are: common “Eggcrate” cardboard egg holders.You have no idea the number of people who tell us their trials and tribulations to find quantities of it, buy it and install it only to find it does little or no soundproofing! This appears to be because it is frequency “holy”.
That is, it has characteristics where sound at certain frequencies passes freely through it! Some have told us that some sound transmissions seems to be somewhat enhanced! foam rubber of the common sort, such as that of which rubber mattresses are made. While this has some possibilities, other disadvantages don’t, (such as it’s durability:), the cost isn’t all that much different than “made for soundproofing” products when so much more of it is needed to be the equivalent of professional materials. Lastly, and maybe most important is that it will burn like crazy!One would think a rubber material would be a good soundproofer and perhaps it is if properly used, but simply laying it on the floor will do little against noise coming in (or going out). Rubber and Neoprene are in the same class here. old mattresses nailed to the walls. This technique has it’s followers, but unless butted well together with no spaces, caulked edges, and only if you are willing to put up with the possible odor, mold and moisture they have or can accumulate, not to mention unwanted rodent critter type “guests” that may take up residence – are they a possibility.
Yes, a lady called to check with us if what she was told was true: that painting her hallway with a dark color would perform a soundproofing job. She had been assured it would. cellulose- the kind that they “pump” into walls. Some people make a living doing this- how? While it’s not useless, it’s not very effective. When you pay big money to have this done, you would want to see some serious results, not have someone say “Well, I THINK I can tell some difference!” (Spray-on wet cellulose over opened walls may be a different matter). carpet – Old or New. Doesn’t make much difference, it will all deteriorate and begin to stink. The newer will take longer, that’s all. Same problems as with the Mattress as explained above. Carpet WILL increase the acoustic absorbency of a room, but do little in the way of soundproofing. (Blocking sound coming through). common fiberglass insulation: makes a great thermal insulator, but not a very good acoustical insulator.
Contrary to the hyped Lab Reports of the drywall manufacturers! plywood panels/ particle board are not good for soundproofing as wood transfers sound very well. hay bales Yes, these make fine soundproofing units, but are rather temporary, subject to fire, critters and vandalism and obviously for outdoor use. Plastic covering can make them more hygienic. Now, our favorite myth- wires in the ceiling!? Sound control is sometimes not easy to understand. Some things that make logical, perfectly good sense don’t seem to work well in practice. Laboratory results don’t always prove out in the field. Field techniques can’t always be duplicated in the lab. One area of misunderstanding is wall space inside a wall. Dead air space works for you, better than filling it up with something like styrofoam, etc.! If you do, sometimes packing stuff in can make the sound transfer worse! A larger air space is superior to several smaller ones. This means a wall with 6″ studs creating a 6″ air space is superior to a wall with 4″ studs and a extra layer of drywall with 1″ air spacing on each side.
Don’t blindly accept the experiences of others who have done soundproofing before, there may be newer materials and techniques that cost less and provide more newly available. There are standard ways of dealing with walls, floors and ceiling, but each case is different. Because of this, different material combinations are required. Run your plan by us, we’ll point out if it can be improved. Use the email link below.This title says it all, basically. I explain that acoustic foam does not block sound about 5 times a day to prospective customers wanting to know how to soundproof. The question invariably comes back, “Why not? Then what the heck is it used for?”It’s not that I’m trying to ruin anyone’s day here – I would love to have foam that could stop sound from going through walls. I would sell a ton of it. But physics is physics and the fact is that we at Acoustical Solutions are not going to sell anything to someone that has zero chance of meeting a customer’s expectations.
Now, a lot of Audiophiles and people very familiar with the nuances of sound will say: “Well if you have a relatively small confined space with a given large sound source the waves will build up and potentially amplify certain frequencies due to modal responses of the shape of container – and therefore adding absorption to the inside of said confined space will indeed reduce overall dB from escaping into the environment,” but that’s not the point, I say.The point I’m trying to make is that putting a few squares of 2” thick foam here and there on a partition wall in an apartment will not keep someone from hearing the other guy’s TV and sub woofer at 3 AM. Even covering the wall 100% with 2” thick foam is not going to, to the extent of the person’s expectations, stop that sound from traveling right through the wall. Using acoustical foam is not how to soundproof.For instance, some speakers used to use foam as the speaker grille cover years ago. If foam is that great at blocking sound, then why do that?
Or the old earphones on Walkman’s from back in the day (I’m showing my age here) – they had foam right over the head phone to make it more comfortable for the listener. The foam in both of those examples was not blocking the sound in any way. The sound just poured right through. Here’s the deal: and blocking are two totally different things. I explain things better with analogies, if you have read any of my previous blogs you will be used to this by now.The color white “reflects” all light, right? And the color Black “absorbs” all light. What we perceive as white is simply just all colors of light mixed together, and what we perceive as black is the absence of all color. Shine a flashlight at a bright piece of tissue paper and you will register a great deal of reflectivity. Shine the flashlight at a dark black colored piece of tissue paper and you will register very little reflectivity.However, being that it’s tissue paper, you put either the white or black paper up against the light and use a rubber band to totally cover the end of the flashlight with it, and you will register nearly the same amount of luminosity traveling through both colors of tissue paper.
Maybe a tiny little less with the black…it’s not a perfect analogy. Splitting hairs aside though, the point is that sound does the same thing: It reflects off certain surfaces and it’s absorbed by other surfaces, in much the same way white reflects light and black absorbs light.When you look at recording studios that have all this fancy foam all over the place, don’t make the assumption that it’s the foam that is blocking sound from going through the wall. They have added layers of mass and caulk and isolation to that wall first to block the sound from traveling through, then added the foam to reduce echoes in the room for various reasons.One of the main reasons foam, or any acoustically absorbent material (baffles, banners, fabric wrapped wall panels, etc.), are used, is to reduce the average reverberation time in a room. A good example of a space that will benefit from adding acoustical absorption is a large gymnasium. Here is an excerpt from a recent email exchange I had with a customer:ME: “Sound goes out from its source and goes until it has simply gone through enough air that it loses energy and falls below the background noise level or below the threshold for our hearing.
If there happens to be a wall, floor, or ceiling in its way before it has gone through that certain amount of air, the sound will bounce right off and head in a different direction still looking for enough air to go through before it dissipates. The louder the sound, the more air (distance) it has to go through to dissipate. PA systems are a great deal louder than a person’s voice. If the sound hits a surface that is very hard and immobile, it will bounce the sound energy at nearly 100% efficiency, which means the sound from a persons voice over a PA system is literally bouncing around the room for about 5 seconds or so. That five seconds is the Reverb Time, or RT 60, of that room. People speak in a quick succession of vowels and consonants, so if the listener is hearing 5 or 10 vowel sounds still hanging in the air with 5 or 10 consonant sounds….all you hear is garble. Hanging Sound Baffles work because they are not 100% efficient at reflecting the sound – in fact they are nearly 100% efficient at NOT reflecting the sound.