I tried to read the Accoustical Thread. I did. Grasping it is a whole 'nother thing. At times I felt like I'd understand reading Shakespeare in Latin better than what was inside of that doozy of a thread.

Anyway, my questions:

1. I have a couple of extra 4x8 sheets of SoundBoard that my drywallers left here. Would they work well as either bass traps or first-reflection-point treatments? (I'd cut them to whatever size needed).

2. Will stuffing leftover fluffy pink insulation in my front corner speaker columns do anything for taming bass?

3. Will those big sheets of hard foam-like insulation at Home Depot do anything for accoustics if I cut them and wrapped 'em in fabric?

4. Does the fabric have to be accoustically transparent to be effective?

1. No
2. not too much but better than nothing
3. No nothing at all don't use em
4. Depends on what it is for, if for covering an acoustic treatment then yes , if covering speakers then yes, if part of a diffusion treatment then no.

As always, McCall, thanks for chiming in! I'm curious....why won't the SoundBoard do anything?

Actually because I didn't know better at the time, I put a layer of Celotex Sound Stop board (sometimes called soundboard) on the ceiling and walls of my Home Office. Note this is the brown stuff, not the homosote board.

Let me tell you That a room covered entirely of soundboard actually sounds sweet. No excessive reverb and nose from adjacent spaces was greatly reduced. Then I went and put up the drywall and it sounds like crap. Typical ringing reverb and the drywall mechanically coupled to the ceiling joists gives off more noise from above then when there was just the soundboard.

I'm not recommending using the sound boards for acoustical treatments but I really liked the sound of my stereo in the office before I put up the drywall.

Well one problem with the Celotex, the brown stuff, is you CANNOT leave it exposed. it grows things one it, really nasty things with the slightest bit of moisture.

Well one problem with the Celotex, the brown stuff, is you CANNOT leave it exposed. it grows things one it, really nasty things with the slightest bit of moisture.

And it smells like dog poop. :D



Glenn

Mine is more like a gray color. It's the stuff from Home Depot. Do they sell homosote or celotex, anyone know? And will this "grow" things? I was at least thinking of putting it inside of my speaker columns...

does it have a brand name on it? celotex does. Home depot used to sell celotex, not sure if they still do. they DO sell Homosote and it IS gray. Homosote if not wetted does not grow things. the celotex however will pick up any moisture in the air and will grow things and if it gets really wet it grows alien life forms big time.
I have some in my walls and will NOT leave any of it exposed to air at all.

........4. Depends on what it is for, if for covering an acoustic treatment then yes , if covering speakers then yes, if part of a diffusion treatment then no.Just a gentle clarification here. Acoustic treatment may include absoption, reflection, or diffusion depending on the base room. In any event covering up diffusive treatments with fabric that is not acoustically transparent could be problematic. Very large semi-cylindrical diffusors designed for low frequencies would be the exception. Covering diffusive treatments with fabric that becomes reflective can render the diffusors ineffective at the reflection frequencies. Use of even "transparent" fabrics to tightly cover QRD type diffusors designed for mid-upper frequencies will incur absorption at those frequencies as well. On the other hand, covering each surface of a QRD type diffusor with something absoprtive can creat an incident angle independent absober.

Yes, I know, too much information -- just saying if you cover up something designed to provide a specific acoustic function you may well change the function. :)

Most people here that use batting for the top portion of their treatments which technically are diffusive not absorbing really do it more to keep the whole area of treatment pushed out to the same amount, rather than specifically for the diffusion. But you are right if you are after diffusion and you cover it with something reflective then yeah that is a problem.

OK, I'm quite unobservant. It is Celotex and it is brown! It's also in my third-car garage and not growing things as far as I know.

Utah is a very dry state -- in more ways than one! -- and I'm only thinking of putting this stuff either in speaker columns or wrapping them in accoustically transparent fabric and slapping on the wall. You still think that's a bad idea if they're not "exposed" but not in the wall like BigMouth's?

I'd still recommend against it. It's not really doing what you want.

As for cloth, the short answer is:

- If you're going to put it in front of speakers or in front a treatment that is not designed nor desired to be absorbant, then you should use a transparent fabric.

- If it's going to be in front of an absorbant treatment like for reflection points, etc - then just get something that isn't too tight a weave so you don't reflect too much of the upper mids and highs.

Bryan

Thanks. Sorry if I'm confusing. By putting this stuff in speaker columns, I mean to put it behind the speakers on the drywall. The part where the sound comes out will be covered in speaker cloth.