# Light soundproofing needed..wall half-built already!



## jlird808 (Nov 2, 2010)

Ok this isnt for a HT but I'm a moderate Shackster and REW user and my boss asked me to help him soundproof his (half-built) conference room. I figured I could maybe get some advise here at HTS 

He's building a new office from the ground up basically. He started building the conference room and realized it could get loud for the people working right outside of the room when ppl start jabbering.

His idea was like the spray in foam stuff but, from what soundproofing knowledge I have, I don't think that's even better than an air gap. I think it should be something that converts audio waves to heat energy right? Should we stuff the walls with R-30? Mineral wool? I can get some 705 actually. We're just trying to control the freq spectrum of the human voice so no bass to worry about.

I'm not sure if he's even willing to add multiple layers of drywall. I threw the idea of a decoupled wall at him and he just said there's NO budget for that. I also suggested MLV and/or Green Glue with more drywall but he wasn't into it. I think he really just wants to stuff something between the studs and slap a layer of drywall on top. On a good note, one side of the wall will have cabinets, counter, huge printer, etc. up to about elbow level. A loaded bookshelf MAY be placed there as well but we were planning/hoping to put it somewhere else :sarcastic:

Any ideas?

THANKS! :T


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## bpape (Sep 14, 2006)

Would he be willing to make the walls 2x6 instead of 2x4? That will lower the resonance of the wall and help some. Fill with insulation - no need to stuff tight. In fact that can make it worse. If you can, make sure he uses 5/8 or even 3/4" drywall on both sides too. That's probably the best you're going to do overall without getting into a more complex structure.

Bryan


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## RBTO (Jan 27, 2010)

If you expand the wall space to 6 inches (good to do), use offset 2x4s. In other words, use a second set of 2x4s to attach the outside wall, but don't let them touch the inside wall sheeting (as shown below). That prevents sound from transferring through the studs. Hope you're not dealing with steel studs - they can be really bad at sound transfer.
There's a soundproofing material that is somewhat like sheet lead that's used to provide sound insulation by doing what you described (damping vibrations and converting them to heat), but I don't know what it's called. Maybe someone else in this forum will be able to help you there. I know a church that used it in a confessional, (one of the parishioners was a sound specialist), and the room is absolutely dead silent, even with loud noises outside. Don't forget the issue of ventilation since soundproofing will also decrease heat transfer, and the room can get hot with several bodies in it.


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## jlird808 (Nov 2, 2010)

Awesome! Those are all great suggestions. I think we're gonna go with just some light fluffy and a couple extra sheets of drywall after all, hopefully 3/4". 

I really like the staggered studs, though the framing is (almost) done.

THANKS AGAIN!


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## jeantyou (May 9, 2012)

You bet they can hear everything just as you do! If you’re renting, you probably won’t want to spend too much money on modifications, so go see how one guy soundproofed the wall of his apartment. If you’re of a mind to take down the drywall on your side or can spare the space for a “false wall” check the construction techniques used to soundproof a house. Soundproof Ceilings? OPTIONS:dontknow:


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