Film-Tech Forum ARCHIVE: Home theater wall fabric help

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Posted by Joe Elliott (Member # 4006) on 07-27-2010, 10:35 PM:

I am converting the front room of the house my wife and I just bought to a theater room. I am looking to cover the walls in a 'soundfold' like fabric, but on the cheap. I have looked up soundfold, and it looks like the composition is not as important as the thickness, as they have a variety of materials available (cotton blend, polyester blend, etc). I thought of going with cheap burlap, but that may not look too good.

For those of you who build theaters (commercial and home), what have you used, and what were your opinions on it? What will work, and be found cheap?

Posted by Martin McCaffery (Member # 37) on 07-28-2010, 01:35 PM:

One important point about Soundfold, or any commercial grade wall covering, is that it is fire resistant. You may want to consider flammability before covering the walls of your home with fabric.

The effectiveness of Soundfold is partially based on the way it is installed - with the brackets to give it that corragated effect which helps block and breakup sound at may frequencies - not just the fabric.

It all defends on what effect you are shooting for.

Posted by Robert Minichino (Member # 3495) on 07-28-2010, 02:17 PM:

The techniques used in commercial theatres really don't apply to small rooms very well. If you just put up absorptive material everywhere, you'll be left with a very boomy sounding room that lacks spaciousness.

There are many DIY techniques and materials for creating acoustic absorbers and diffusers that are as effective or better than expensive commercial materials. As Martin mentioned, it is important to use fire retardant materials. You can always use acoustically transparent cloth to cover up an ugly treatment, too.

For information on laying out the acoustic treatments in your home theatre, I recommend reading Chapter 22 of "Sound Reproduction" by Floyd Toole.

Posted by Frank Angel (Member # 248) on 07-28-2010, 02:34 PM:

I saw an on-the-cheap setup where the back wall was covered with regular household attic fiber insulation. I think it was fiberglass, although I can't be sure of that -- it was that yellowish fiber cotton candy type stuff with a metalic looking backing; he put the backing against the wall and stapled it leaving the fiber facing the room. Then he covered all of it with a very lightweight china silk which is pretty much acoustically transparant. The combination makes a very good sound absorbing surface, which is important for the rear wall especially. Sound travels thru the fabric into the very good sound absorbing insulation material. In this particular case the china silk was pleated and two different shades of color were used, alternating in panels. It was very attractive. I suppose you could treat all three walls that way, but that probably wouldn't be a good idea as you can deaden a room TOO much.

It's the back wall that is the one most in need of a good absorbing surface. Usually if you have speech intelligibility problems, you need to look at the back wall first. Hanging heavier velour curtains on one side or on both sides of the room (but without the need for insulation behind it) would usually be more than enough deadening for movie sound. A room that is too dead will cause the sound to have a lifeless, artificial quality.

In this same insulation, he also used simple corrogated egg cartons -- the ones made with pulverized cardboard that is moulded into the common dozen eggs carton. The surface is very rough and the egg "indentations" make great sound dispersing hills and valleys. He stapled the cartons to ceiling from the screen proscenium to about 1/3rd the way back. He claimed those simple egg cartons made a definate improvement on the overall sound.

That's about as cheap a way you can go, although this was quite a few years ago; today you would probably be hard pressed to find a supplier of those cheap corrogated cardboard egg cartons because now in the supermarket all you find is styrofoam or plastic.

As for the fire issue -- you can buy lots of fabric that is flame retardant; the Rose Brand Theatrical fabric line is almost all Flame Retardant, or you can buy a chemical that you dip fabric into (as well as cardboard egg cartons too, I guess) that renders the fabric FR.

Posted by Joe Elliott (Member # 4006) on 07-28-2010, 03:09 PM:

1. "One important point about Soundfold, or any commercial grade wall covering, is that it is fire resistant."

noted

2. "The effectiveness of Soundfold is partially based on the way it is installed"

Actually, I was looking for the look of a theater as much as sound absorption. The room was lathe and plaster on the rear wall, and plaster over drywall on the remaining 3. I've replaced soundfold before, both with the brackets, and (and the way I would be installing it) pleats simply folded over and stapled to a 1x2. I was still just an usher back then, so I don't know what the difference between the sounds of those two installation methods.

3. "I recommend reading Chapter 22 of "Sound Reproduction" by Floyd Toole."

Will do.

4. "It's the back wall that is the one most in need of a good absorbing surface."

Good, because I think the back wall will be acoustically the worst.

As for the ceiling, I don't know if it will be a problem, as it has 4x8 wooden beams every 4 feet, parallel to the screen. This may break up the sound enough, but I can cross that bridge when I come to it. My first hurdle is the walls, and surround system. The projector is currently in place, but we are projecting on a flat grey wall. It works for now. I will try to post a picture of what I have in mind, but it won't be for a couple of days, as I am heading off to work now, and tomorrow . . well we all know how fun Thursdays can be.

Posted by Bruce Hansen (Member # 281) on 07-28-2010, 08:42 PM:

Sometimes just glueing a rug to the wall will be enough. The "outdoor" type of rug comes in a number of colors (not the "grass" stuff).

Posted by Mike Blakesley (Member # 26) on 08-02-2010, 08:47 PM:

Dirty little secret: Soundfold is just burlap that's been treated with anti-flammability chemical and dyed. I haven't priced it out in years but it's nothing magical. As stated, it's the pleats that do the work. Just about any thick cloth would work the same way.