marc-s

soundproofing my home theater

what do u recommend for the best soundproofing at the most affordable rate?

i have been told of a drywall material which is as effective as 5 regular pieces of drywall.

of course i have been recommended a cork material as well

what material do u guys recommend whether it be the above or other material?

thanks

marc

Gerry S

Re: soundproofing my home theater

I guess you are referring to quietrock. The cork sounds useless.

When it comes to containing sound, mass and isolation are what you need to consider.

There are also building techniques you can consider, if the walls have not been built yet. For example, a staggered stud wall can help minimize sound transmission to other rooms. Some even build a room within a room, to completely isolate the walls and ceilings, and thus prevent the transmission of sound.

There is much to learn about this topic. My plan is to use two layers of 5/8" drywall with a layer of green glue between. The product comes highly recommended by some respected theater builders. There website has a ton of information that you should read to learn about sound isolation, including independent lab tests comparing solutions:

http://www.greengluecompany.com/

good luck.
-Gerry

BruceSpielbauer

Re: soundproofing my home theater

The above response is excellent. I will add to it, and mention this:

1- There is no such thing as soundproofing. You can reduce the amount of audio which enters or leaves a room. That is all.
2- The best "bang for the buck" seems to be what you are asking about. Sadly, most of the techniques for reducing sound travel also tend to cost quite a bit of money. There are a few exceptions. IF you are still in the early construction phase, then you can incorporate some of the ones which do not set you back a ton of bucks. For example, staggered stud walls do not cost all that much more than a regular stud wall, if you can give up a bit of space. And, a true double wall can also be done for not that much more, since you are mostly doubling up on construction-grade lumber. The results of these approaches have been scientifically measured, and the results are always effective, compared to other techniques.
Or, consider double drywall. Obviously, more money, But, compared with many of the products available, this can often be much, much les expensive than throwing your money at some product. And, it is a definite sound reducer.
3- The subwoofer... when you you do your research, you need to realize that almost all of it uses a scale which ignores the subwoofer noise. You will see lots of results which talk about reduced STC levels. This is valuable, as long as you remember that it ignores all low frequency stuff -- your subwoofer. And, unfortunately, the subwoofer noise seems to eb the toughest type of sound to try to kill.
4-The reply above mentions Green Glue -- great product. Uses scientific test to validate their claims. As mentioned, cork will be next to useless, or more likely useless. I am going to suggest you read a report from their web site carefully, in fact you should read all of the reports. NOT because you should spend the money on their product. But, because they deal in the truth, and if you notice their emphasis on mass, and decoupling, and resonance, and damping, you will be able to quickly answer your questions above.

Later, you can decide if their product is worth it, as an ADDED feature.

Here is the article:

http://www.greengluecompany.com/five...ndproofing.php

-Bruce
-A customized intro for your home theater: http://www.S2Digital.com

Jeff Kelley

Re: soundproofing my home theater

What about roxul safe n sound insulation? Does it work?

Jeff

AquaSerge

Re: soundproofing my home theater

I plan on creating commercial business with HT setups in each room (pretty much a HT theatre if you can call it that) and my idea for sound dampening in each room is using the THX qualified quietrock, with some insallation (after I take a look at it it might even be safe n sound insallation) inbetween each wall. Because I will actuall have 2 layers of this material (one layer on each side of the wall) it should nullify pretty much all noticable sound leaking from either side. This may be overkill, however keeping sound from leaking from one room to another is extremely crucial in my case, and replacing drywall in a commercial area is alot cheaper than replacing damaged or destroyed sound panels. I have yet to test this theory but from those I have talked to it doesnt sound like a bad idea. Even if this is overkill, customizing a little of what I have suggested could be exactally what you are looking for.

If you could apply that to your senario i think it would help alot. any suggestions on my idea would also be appreciated.

Robert_J

Re: soundproofing my home theater

Double drywall and QuietRock will stop the majority of the sound from leaking. But you have to go to the next level if you want to contain reference level bass. Room within a room. I went with staggered studs and that stops the highs pretty well. But my subs will vibrate the entire concrete foundation of my house at reference levels.

-Robert

AquaSerge

Re: soundproofing my home theater

I think i get the idea of a room in a room, but im not so sure on staggard studs. Could anyone enlighten us newbs to these methods?

Robert_J

Re: soundproofing my home theater

Here's a chart of how much the basic construction techniques work - link.

How To Build A Staggered Stud Wall - Google is your friend.

-Robert

BruceSpielbauer

Re: soundproofing my home theater

Robert's chart above is an excellent one. Study it, carefully. I found a very similar one, and because the results are based on scientific testing, you should pay careful attention.

Now, for the only caveat... The chart that Robert provided (and also the one that I consulted) both display the STC reduction you can expect. While this is a very valuable measurement, we should also keep in mind that the STC measurement completely ignores one area of sound: the low bass.

Read what follows, carefully:

"The STC number is derived from sound attenuation values tested at sixteen standard frequencies from 125 Hz to 4000 Hz. These transmission-loss values are then plotted on a sound pressure level graph and the resulting curve is compared to a standard reference contour. Acoustical engineers fit these values to the appropriate TL Curve (or Transmission Loss) to determine an STC rating. The measurement is accurate for speech sounds but less so for amplified music, mechanical equipment noise, transportation noise or any sound with substantial low-frequency energy below 125 Hz. "

What this means is that STC completely ignores any frequencies below 125 Hz. And, anyone who has set up a subwoofer knows that the most common cut-offs for sound that is sent to a subwoofer is usually a ways below that. (note that 80 Hz is often the reference level starting point). This means that ALL of the sound from your subwoofer is not even measured in those tests that were performed to make up the charts you will see. Sadly, there is no universally-accepted measure for your subwoofer "thump," so you will probably not find any scientific data on reducing the subwoofer noise.

Worse, those who have tried to reduce sound transference in a home theater will attest that the subwoofer noise tends to be the TOUGHEST type of noise to try to reduce. Think of the last time you were stuck at an intersection and noticed the "thumpph! thumpph! thumpph! " coming from that car which was four cars behind you, waiting on the same traffic light. Note that you did not hear the rest of the music that the offender was listening to. You did not hear the guitar, or the pianos, or the vocals, or the high-pitched whine of the lead guitarist. For some reason, you only heard the "thumpph! thumpph! thumpph!" coming from the subwoofer. The subwoofer noise (the LFE or low frequency noise) tends to be the most difficult to reduce. The car's chassis and the car's doors, and the air gap between his car and your car managed to greatly reduce the vocal track, and the rhythm guitar, and the horns, and the keyboard, and the lead guitarist. Yet, none of those things seemed to have much impact on the subwoofer "thuumph!" And, the chart referred to above does not even measure that same subwoofer "thuumph!" at all.

My own thoughts... The same sorts of construction which reduce STC also does reduce the LFE or subwoofer noise. Somewhat. However, I have noticed that a lot of the subwoofer noise will typically still get through. From my own experience, if you hope to greatly reduce the subwoofer noise, one may have to examine the true room-within-a-room approach, complete with air-tight sealed up seams, and add decoupling, as well. And, this also means you carefully examine what the weakest link might be -- for example, replacing regular doors with a heavy solid core exterior door, complete with threshold, perhaps even using two doors separated by an air gap.

I am not trying to "dis" the chart in any way. Rather, I would hate for anyone to follow it and expect nirvana-like results, only to discover they still have complaints of a "thuumph! thuumph! thuumph!" throughout the rest of the house, after putting in a great deal of effort.

Take care,

-Bruce
-The ultimate Home Theater Add-On: http://www.S2Digital.com