Room Within a Room

g.a.harry · Post by **g.a.harry** » Sat Feb 26, 2011 9:13 pm

The seemingly universal opinion in the audio world is that the only way to really prevent sound transfer between structures is to build a room within a room. I agree... so that's what I plan to do. But, caveat and design challenge, I can't do anything to the room that I'm in.

My thought: Isolation booth w/ floating floor. Yes? So, I've drawn me up some plans, figured out how to economically yet efficiently float the floor. Walls will be 3.5" thick: 1/2 inch ply on the outside, 2 inch rigid fiberglass on the inside.

New question arises. What to stuff into that extra inch? I had thought to use that rigid pink foam stuff, but it only comes in 2" thickness (as far as I know). Maybe another layer of ply to create an air pocket?

Is there a definite best choice of anti-sound-transfer sandwich material? I'm trying to think of stuff that won't be too heavy. The whole thing is designed to be modular and transportable.

Thanks

..W..

MoreSpaceEcho · Post by **MoreSpaceEcho** » Sat Feb 26, 2011 9:49 pm

unfortunately i think it needs to be really heavy if it's going to be the least bit soundproof. as for the extra inch, from outside to inside i would go:

1/2" sheetrock
1/2" ply
1/2" sheetrock
2" rigid glass

it will weigh a ton and you'll never ever move it.

what size are you thinking of making it? what are you intending to put in there? amps/singers?

norton · Post by **norton** » Sun Feb 27, 2011 8:06 am

Yup. Mass in that extra inch. Sheet rock would be a great choice...cheap easy to manipulate etc. Stay far away from any styrofoam... No sonic benefits as far as transmission, or absorption in that material.

Nick Sevilla · Post by **Nick Sevilla** » Sun Feb 27, 2011 9:26 am

Mass Loaded Vinyl.

I used it to great effect in my studio.

Not cheap, but I find it is the best $$$ per square foot of isolation, in a thin enough material to be useful in a wall build.

Cheers

g.a.harry · Post by **g.a.harry** » Sun Feb 27, 2011 9:56 am

Sorry, I was half-asleep when I wrote that, should have mentioned what I'm using it for.

My main focus at the moment is on doing voice-over/ADR, audiobooks, and foley. So I don't need that much space, but enough to be comfortable for someone to sit inside for extended periods. I was aiming for an internal dimension of about 5' x 6' x 6'6". The room that it'll be in is about 9' x 8' x 7'9" and I'd like to have a bit of space around it to store mic/music stands, some foley gear and the like.

I won't be having a full band going on outside or anything, so it doesn't need to be absolutely soundproof. But I'm in a basement with no insulation between the upstairs floor and my ceiling, and I've got the furnace down here. Even with the furnace going, my room isn't all that bad. I just need a bit of isolation so my sessions won't have to depend on when the people upstairs are home/moving around. Hence the non-monstrous thickness of the walls.

g.a.harry · Post by **g.a.harry** » Sun Feb 27, 2011 10:54 am

Something just occurred to me. What about two 1/2" sheets of ply with green glue or quietglue in between? The stuff is supposed to be magic for low-end transmission.

MoreSpaceEcho · Post by **MoreSpaceEcho** » Sun Feb 27, 2011 12:12 pm

that would work. green glue is expensive (and really sticky. it smells nice though) but it does apparently do what they say it does.

oh, i just looked at your post again and you said two layers of ply....i think you'd do better with two layers of sheetrock instead....pretty sure it has more mass to it than ply, but one of the smart guys here is gonna have to check my math on that one.

JWL · Post by **JWL** » Tue Mar 01, 2011 12:14 am

A few thoughts:

I prefer using Green Glue to using MLV. MLV has its fans, but I think Green Glue is more effective, and cheaper.

Drywall gives the most mass bang for the buck.

In most cases I don't recommend floating the floor. A lot of work, and in most cases it hurts rather than helps isolation.

Get Rod Gervais' book, Home Recording Studios, Build It Like The Pros. Get it now. Read it.

g.a.harry · Post by **g.a.harry** » Tue Mar 01, 2011 7:44 pm

@JWL: I must say that I kind of feel like a jerk, I just realized that I've seen you mention Gervais' book at least 8 times in various places around the site, and yet I keep on asking my silly questions.

As far as the floating the floor thing goes, I wasn't planning on doing anything more complicated than plywood on hockey pucks. However, now that I see it on screen, it feels like it might be a silly idea.

roscoenyc · Post by **roscoenyc** » Thu Mar 03, 2011 5:02 am

the Gervais book is totally invaluable.
The only reason not to get it is if you really like to make big, costly, troublesome to correct mistakes.

g.a.harry · Post by **g.a.harry** » Mon Mar 07, 2011 8:52 am

While I wait for my copy to arrive...

What about the door to a booth this size? I'm particularly worried about good seals (obviously). Anybody have any experience with this?

goldstar · Post by **goldstar** » Mon Mar 07, 2011 6:59 pm

Best low-budget door is to use an exterior jamb with a 1.75" solid-core door. The ext. jamb will have weather-stripping already on the top and sides, so all you need is a drop-down sweep for the bottom.

If you can get away with it (ie don't need a lock), have it not drilled for a knob and use a roller catch. That way you'll avoid a 2+" hole for the knob.

Zero International makes good door seals; here's a Pemko.

http://www.pemko.com/index.cfm?event=pr ... aterialId=

I agree w/ J; skip the hockey pucks.

Frank

goldstar · Post by **goldstar** » Mon Mar 07, 2011 7:02 pm

Best low-budget door is to use an exterior jamb with a 1.75" solid-core door. The ext. jamb will have weather-stripping already on the top and sides, so all you need is a drop-down sweep for the bottom.

If you can get away with it (ie don't need a lock), have it not drilled for a knob and use a roller catch. That way you'll avoid a 2+" hole for the knob.

Zero International makes good door seals; here's a Pemko.

http://www.pemko.com/index.cfm?event=pr ... aterialId=

I agree w/ J; skip the hockey pucks.

Frank

Message Board

Room Within a Room

Room Within a Room

Who is online