Foam Acoustic Wall Treatment... I really need help!

pisces7378

New member
i know that this topic has been delt with hundreds of times and from several different angles. However I cannot find anywhere that my exact question has been delt with.

My question is about foam density and shape. I have seen of course the Auralex foam squares and corner bass trapes in online music stores and magazines. It is fucking expensive and completely impractical for a room the size of mine (VERY TINY!!! 7.5ft cieling, 4ft deep X 5.5ft wide) So I asked at my local music store and the guy turned me on to this store that sells nothing but foam. Foam for couches, cushions, suit cases, brief cases etc. Well I went down there and was very impressed. They have it all it seems as far as foam goes. Thick, thin, high density, fluffy, all colors and on and on.

Now, I have never actually touched "real" studio foam squares so I do not know which density to be looking for. Also, I have seen that Auralex studio foam has either these little pyramid peaks all over it or sometimes just raises rows of long triangles. I didn't see any of that kind of foam. I only saw sheets of foam in all thicknesses, from 1/2 inch to 6 inches thich. For recording vocals I want to make this room acoustically DEAD!

What should I be looking for?

Does the shape of the foam matter? (i.e will the fact that I do not have little pyramids everywhere effect the sound THAT much in such a small room?

Should I vary the thicknesses, as in put 2ft X 2ft squares all over but stager 1in. thich with 2 in. thich squares; checkerboard style? Or is that just a waste of time?

I have a 40Watt light bulb in a glass case fixture on the cieleing... how close should I get to it without risking melting or worse yet... poisionous gas from melting foam?

Should I worry about the floor? It is hard wood. There is a computer table in here along with a computer chair, so there is really only about 2ft X 2ft. of floor actually visable once I am in the room.

Now, for recording acoustic guitar through my new AKG C451 B mic...

Should I make it so that I can remove these wall treatments to record the guitar? Do you guys really think that I can get ANY room ambience out of this closet or should I just record the guitar DEAD, as in attach the foam to the WALL instead of a removable board, and then try to fake room ambience with reverb?

Please remember that getting board for me to attach foam to will DOUBLE if not TRIPPLE my budget for this project (and my budget is SMALL). So do not come up with the old... "Well I would put it on the boards just to remain flexible... you know... just in case you don't like it." If you think that I should get propper plywood boards for this then provide a real reason for this.

Thanks guys... you are the most helpful bunch of blokes on the net!
 
pieces, I hope you don't mind but I've moved this thread to "studio building and display", where all the foam guys hang out :)

Slackmaster 2000
 
I would do a search on knauf - they are the European version of Owens-Corning 703 type rigid fiberglas insulation. This stuff has better low freq absorbtion than foam, and is about the same price as the lower cost foam. I would deaden the entire booth including the ceiling, since the size is so small as to not be able to support any kind of reverberant field. The 2", 3 lbs/cu.ft. stuff is what you want. You can cover it with burlap, or any open weave cloth. The light fixture shouldn't get hot enough to matter to the fiberglas, but I'd keep the cloth at least 2" away.

You didn't mention what kind of reverb processor you have, whether it's soft or hardware, etc, but it would have to be pretty bad not to beat whatever you could get out of that small a closet.

Also, once you get going, be careful about mic/instrument placement - you don't want either to be centered between any pair of walls, including floor and ceiling, or you will get serious nulls in frequency response. I know you won't have a lot of choice in this, but try to stay away from center in ALL directions, both with mic AND guitar (or voice, for that matter)

Fastening the fiberglas to walls can be done with construction adhesive, or rubber cement if you want it more temporary. I'd test whatever adhesive you use on a scrap piece of the material first, just in case there's a serious incompatibility... Steve
 
Just wanted to add that Alton Everest, pretty much the authority on studio acoustics, says rigid fiberglass is every bit as good, if not better than, the high priced foam except when it comes to impressing clients.
 
foam

pisces7378
I wholeheartedly agree with everyone about foam. Its not gonna do much . And I'm a newb.

Yup I went with Auralex, about 300 bucks worth about 5 years ago. Wish I was lurking HR then!! All it really did was kill all the high end. Allthough the lenrd's(corner traps) did help alittle.

But as soon as I learned about the 703 and bass traps, broadband resonators and acoustics in general, my room cleaned tremendously. But hey I'm still not finished with my converted garage.

Best listen to the guru's here.

Good luck

T
 
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