acoustic panels

Hello All, I'm getting ready to build more acoustic panels for my live room. Last time around, I went through the long drawn out process of building wooden frames and stuffing them with rockwool. Ultimately they will be wrapped in fabric. They'll be awesome... whatever... Anyway, this time, I don't have the energy to go through that entire process again. I'm thinking about buying some 2" and 3" yellow compressed fiberglass boards and wrapping them in fabric. Product like OC 703. Anyway, I was calling around trying to track some down and I came across a product that's not exactly the same thing, but the supplier is willing to basically hand the stuff over for free cause they don't stock it anymore... It's a certainTeed product. http://www.certainteed.com/NR/rdonlyres/C41B47AA-C400-4D5C-88A6-C957B43C7067/0/3025021.pdf cb 225 density 1" board. The only problem I see with this stuff is it has a foil backing and it's not as rigid as most board... The grand plan would be to glue several pieces together to get a total thickness of 3" and then wrap them in fabric... I have no idea how they'll perform or if it's worth the trouble... if anyone has any ideas or experience with this stuff, please let me know... Free isn't always trouble Free. over and out, andrew

Moderators: Can/should this thread be moved to the Acoustics forum?

Not as rigid probably because the density is less than 703 - still a useful range, depending on how hard it is to remove the backing. If it's too hard, I'd pass... Steve

So I should definitely take the backing off? I'll give it a shot... Keep ya posted, thank you, andrew

Certainteed also makes other board products that are similar to 703 in density and coefficients. They are available in faced and unfaced.

Andrew, > So I should definitely take the backing off? < Probably not for bass trapping. See my Density Report, which also shows the performance of FRK versus non-FRK rigid fiberglass. --Ethan

Ethan, he's talking about ONE INCH board, EACH with a facing, and using MULTIPLE LAYERS... :wink:

Usually using OC703, to get a rigid frame without a wood frame, you have to spray fiberglass on the thickness side of it and a few inches at the back of the panel, then glue the fabric at the back with 3M 77 contact spray. But for shoothig fiberglass on your panels you will need a shop with good ventilation and a mask to do it, plus compressor, gun and a good cleanup after, and finally some skills to make the fibreglass receipe . :roll:

Steve, > he's talking about ONE INCH board, EACH with a facing < I was replying to this: "I'm thinking about buying some 2" and 3" yellow compressed fiberglass boards" --Ethan

Hello, Sorry I'm a little late to the party... Ethan & Steve, I have 1" faced boards that are available to me at no cost. I'm starting to think it's will be too much trouble to turn these boards into fabric covered acoustic panels... Especially if I have to remove the facing, then glue them together to reach the appropriate thickness. In this case should I remove the facing? Secondly, another possible use is in my control room I already have some nice frames built which I was planning to stuff with 3" mineral wool and cover the frames in fabric. Perhaps I should leave the backing on my 1" panels and just stuff 3 panels in the frames as is, not even glue them together... Do you think this could be just as effective as 3" mineral wool? thank you, andrew:)

Andrew, > I'm starting to think it's will be too much trouble < Not at all. The facing peels off easily, and you don't need or want to glue them together. Just stack 'em up and wrap fabric around the lot. > Perhaps I should leave the backing on my 1" panels and just stuff 3 panels in the frames as is < Yes, exactly. --Ethan

Ethan, if you were taking 3 1" panels and wrapping them in fabric, would you leave the backing on and have it face forward (into the room). Or would you remove all the backing on each panel, then wrap them? thanks:) andrew

Andrew, > would you leave the backing on and have it face forward (into the room) < Yes, but only on the one panel that faces the room. All the other panels should have the paper removed. --Ethan

Hello again, thank you for all the tips about the panels. I'm looking forward to removing the foil from the 1 inch panels and replacing the mineral wool I used in my first panels with the 1" board. I'm trying to track down the right product to use for building fabric wrapped panels without frames. I need to purchase a strong enough fiber glass panel that won't bend when I wrap it and the corners will still look nice and sharp. Will oc 703 do the trick? Or do I need something more rigid? thanks:) andrew

703 will work fine. It's a very good all around solution. If your goal is purely bass absorbtion, try to get 705 and mix 2" unfaced with a piece of 2" FRK with the foil facing the room.

Sorry Ethan, details got a bit fuzzy there. Guess we were each replying to different bits of "fuzz" :lol:

Hey Steve, I'm a bit confused, guess I joined the party late again? Steve do you have any thoughts on this subject? How will the edges of 703 look after it's wrapped? As good as a wooden frame? Or do I need to get something that's 6 pcf instead of 3 to achieve that result? thanks! andrew

Andrew, I'm probably the world's worst "Christmas Present Wrapper", but I don't particularly like the way 703 comes out when wrapped - not as "crisp" as you might like. The denser boards work better, and acoustically seem to work at least as well, especially for lower bass. The other possible work-around is to do as Serge mentioned and "butter" the edges with resin/hardener - this takes a bit of skill/practice to get right, but results in a trap that's a bit better for mid frequency grazing incidence than the heavier batts but with cleaner looking edges when wrapped without a frame... Steve

Hey steve, By denser do you mean 6 pcf 700 series board by oc? Also, do you know the model number of the certanteed product that is the equivilent? The stuff I'm thinking about is yellow, nice and smooth on one side and a bit bumpy on the other. I feel like I might be kicking myself here by trying to avoid building the wooden frames. I'm hoping the 6 pcf boards will work just as nicely without having to apply a resin... thanks again, andrew

I agree. You CAN make the 703 look decent without framing but it's tougher. 705 frameless works better for looks. As for acoustical properties, it depends on what it's for. For reflection panels, I prefer 703 as shallow angles of incidence can cuase high frequencies to graze off of the denser materials - kind of like skipping a rock on water.

Hello Hello, I'm using the panels in hopes to control the crazy amount of reflection/reverb in my live room... At this point, I'm not sure how much of the reflection is low or high freq. The room is empty and it's unbearable to even have a conversation in there... maybe I need to have a mixture of 703 and 705. I'm have a lot of trouble tracking down any 705 because as far as I can tell, suppliers have to buy it by the truckload. andrew

These guys, at least in my area, have a fair variety of products available; any rigid board material with the same PCF will act similarly enough to be interchangeable - IOW, 6 PCF is 6 PCF, more or less - http://www.spi-co.com/servicecenterdirectory.mv Steve

I've actually talked with the folks at SPI. The problem I'm encountering is I'm looking for 4x8 or 4x10 panels. Also, they don't seem to keep 6 pcf oc or certanteed on hand. Is there something else I should be asking for? I'm afraid if I don't get the right kind of board, the face won't look so nice when it's covered in fabric... thanks steve:) andrew