Sound Isolation

[MikeS]

You studio aficionados…

My buddy and I are looking to enlarge and upgrade our studio. While enlarging the space is of great concern for us, our #1 priority is sound isolation. I have an idea of what to do to keep reverberation at a minimum for recording purposes, but we are also very concerned with noise leaking from the space, especially through the ceiling (the studio is unfortunately below a bedroom that will, come February, become a nursery). For walls, I have no doubt that sound attenuation batts will be adequate to keep most noises from leaking into rest of the bottom floor. For the ceiling, batts will help quell the noise, but I fear they will not stop enough low frequencies.

I know that for low frequencies, solid mass (ie – concrete) are best. That’s obviously not an option for an existing ceiling. I know you can also get 2lb vinyl sheets that block up to 90% of sound transmission, but the material is very expensive, and I’ve estimated it to cost over $1000 to do the ceiling alone in the vinyl…

So I’m asking those that have built or regularly work in studios, what are some cost-effective solutions to keeping sound in the room?

 

[Zhangliqun]

Re: Sound Isolation

There is something called a "bass trap", that requires a small portion of a wall to be recessed, I think by a foot or two -- or of course, build the wall out further and leave the original wall alone where you want the trap. It sort of looks like a mini-fireplace with some baffling hanging around it.

I'm no expert on this so that's as far as I can help you with that. But try googling "bass trap", etc.

 

[Zhangliqun]

Re: Sound Isolation

Actually, according to the pictures on this site, bass traps can be a lot bigger than a fire place. But hopefully this site can help you. Apparently it's not too terribly expensive if your handy with woodworking, etc.

http://www.ethanwiner.com/basstrap.html

 

[JacksonMIA]

Re: Sound Isolation

I don't have any experience with it and can only tell you what I read while I was researching it when I was thinking about soundproofing a garage, but it seems to make sense to me. I'd be interested to hear the opinions of those who've had experience as to how they feel about it.

One thing I read was that it's the density of the material that really blocks noise. One site recommended using sheetrock lined with lead (they actually sell this stuff, but I bet it's expensive) for the walls.

Another thing I read that might be helpful was having two walls non-parallel. They were referring to things such as the window between the two rooms - mount the panels of glass at an angle to each other to minimize sound transfer. It makes sense that this would also work with walls, ceilings, and floors. Obviously, the bedroom above will have a flat floor - there's no way around that, so mount the new ceiling at an angle.

Again, I don't know if this will help or not, so hopefully someone with some experience in the matter will share with us. But it shouldn't cost much more to angle the ceiling a bit if that will in fact help you.

 

[tone4days]

Re: Sound Isolation

most effective sound proofing i ever observed first hand was a 'room within a room' in the basement of a friend's house ... the dead air gap 'between the rooms' was the most effective sound barrier imagineable .. he built it up on a slightly (4" or so?) raised floor that was 'decoupled' from the foundation by thick rubber pylons ... had a marshall stack cranked in the room and outside of the outer room, you could not hear it at all ... biggest problem was that it got to be hot as hell and stuffy in there (no ventilation) ... there was no duct work to transmit air handling noise though ... the ceiling was completely isolated by an airgap from the floor above it ..

option?

good luck
t4d

 

[MikeS]

Re: Sound Isolation

Yeah, t4d, after making that post I began doing a bunch of research on it. I probably should have done that before posting. I’ve heard of rooms within rooms before, but I’m not sure how feasible it is. It’s defiantly no an option for the floor, but may be for the ceilings and walls. I’m waiting for my buddy to get back with me. Essentially, I’d like to do a variation of the room within a room, but I’m not sure it’s financially feasible.

Anyway, I found out that disconnection and density are the two ways to provide sound isolation. Disconnection stops structure-borne sound transmission (the room within a room is the example for this). The density stops air-borne sound transmission. I also found a bunch of products for this, but they are not cheap. Go figure. The most abundant material is a PVC based vinyl sheet, approximately 1/8” thick, that is very dense. It is somewhat similar to the car based sound attenuation material commonly known as Dynamat. It’s very dense and used behind drywall to help isolate sound.

Zhangliqun, “bass trap” and other foams are sound quality devices, and not effective in stopping sound from traveling from room to room.

I know what has been proven to work. That much research is easy… but what I’d still like to know is if anyone has employed any sound attenuation and isolation methods that were a little easier on the wallet?

 

[darkshadow54321]

Re: Sound Isolation

I've heard that sticking egg boxes to the walls helps... but I doubt it's truly effective, and it looks ugly too.