Need Help Stopping Low Frequencies. Suggestions Please!

[justinmichael]

I posted this in the acoustic and soundproofing forum..
but I am not sure how active that forum is...
I know that some of you guys here could probably help me..
read below. thanks!!

Fellow Gearslutz,

I need your help! I just purchased a live/work loft and I plan on having my studio inside the unit. I ran some tests with my monitors (Dynaudio BM6a's) and I found that the high frequencies were NOT passing through the walls into to the other lofts, however the bass could be heard in the nextdoor units.

I contacted the developer and they told me that the lofts were built with a double wall structure..

(drywall --> 4 inch studs --> insulation --> 2 inches of dead air ---> insulation -->4 inch studs --> drywall) .

They told me that the walls were about 11 - 12 inches thick and wern't touching eachother to stop any vibrations between the units. Unfortunately, not enough to stop low end frequencies.

how can I prevent the bass from leaking? any recommendations?
Can I build something over the existing dry walls?
Will real traps / bass traps be enough to absorb some low frequencies?
Please give me all your suggestions..

I have looked at websites such as Soundproofing and Acoustic Materials

has anyone used this company before?

thanks,
Justin

[Hamburg58]

Want to save money? Call one of your favorite gear resellers and ask them for advice. Draw out your room dimensions and details and what not...Shoot it to them, see what they can recommend... I know sweetwater does that for free....Just and idea. If you don't want to go that route, I know a few Acousticians but that will be a lot of $$$

[radkins]

Bass traps wont do anything, you need layers of mass (plywood/drywall), something that will take alot of energy to resonate. Check around and I'm sure you can find a specific way to do this. I can't remember.

[Kiwiburger]

You are pretty much screwed. Sound proofing (as opposed to sound treatment) is practically impossible.

Sound = vibrating air. Air is a fluid. Energy is never lost. Combine those basic principles, and you can see that you have a huge problem.

You need to create an airtight room - the smallest hole will allow air pressure to escape - meaning sound can propagate through the smallest hole.

You also need to prevent the air pressure in your room from physically coupling to the next wall layer.

In theory - what your builder says has been done is the answer (two walls, with an airgap, not touching). In reality, I suspect that this was not achieved. Very probably the whole concept was defeated by a builder who did not understand the basic principles, and coupled the inner wall with the outer wall. A single nail would do it.

You could create another room-within-a-room. It would have to be floating (e.g. rubber mounted). Expensive, but about your only hope of true soundproofing.

The other alternative is lots of mass. But that would probably require a complete re-engineering of your foundations and everything. That's why I built a new building, in solid concrete.

[Ethan Winer]

Originally Posted by justinmichael

the bass could be heard in the nextdoor units.

Kiwi nailed it - sound isolation is very difficult and requires construction techniques, not stuff slapped onto the walls. You'll find a lot of good advice here, and their product is very highly regarded:

Green Glue is your soundproofing and noise reduction material

And here:

Amazon.com: Home Recording Studio: Build it Like the Pros: Rod Gervais: Books

--Ethan