Originally Posted by pilsnick
Appreciate the link. I have thought of putting family pictures over acoustic panels in my living room to help with room reflections. Ever since I installed hardwood flooring, I noticed how much sound travels around the house.
My theater (11' x 16' x 7.8') is on the narrower side (11' wide) so I've been looking for ways to make the panels so they don't stick out too much from the side walls. I've been reading up on frameless acoustic panels. I found a discussion on gearslutz where someone used Roman PRO-543 on the edges to stiffen them and then wrapped fabric like GOM around it; using 3M adhesive spray to hold the fabric to the panel. I've also been looking at different diffusion options. Also on gearslutz, I saw a suggesting on copying a BAD example. I was thinking of blowing up a picture of a BAD, overlaying it 4 layers of 2' x 4' x 1/4" MDO panels and drilling a bunch of holes. Then I was was going to use spray adhesive to hold the BAD panel onto OC703/705. Do you see anything wrong with this approach? Thanks.
Yeah, acoustics get tougher and tougher as the space gets smaller, but that is where treatments can help, as you know.
I guess I haven't seen many people trying to apply something to harden the edges. OK, I haven't seen anyone try to do that. I understand the concept of a frameless panel, but what is your objective with it? To save 1.5" of width and height? To make the panel thinner somehow?
The absorption material performance increases the thicker it is, we know that, but if you take some material and add an air gap behind it, it performs almost as good as if it was full insulation thickness (2" of OC703 plus 2" air gap is almost as good as 4" of OC703, but at a lot less cost).
I'm not saying that you need to put something 4" thick on your walls, but you are going to want at least 2" of OC703 equivalent absorption material for a broadband panel, and at that point you could frame it with 1x3 poplar for pretty cheap, have something with crisp edges that could also be rounded over, beveled, or whatever if desired, be just 2.5" thick, have a small bump of "free" air gap performance, and have something rigid to attach mounting hardware to.
BAD panels are a fun experiment in being able to make precision drill holes. You could make a couple and stick the acoustic insulation to the back using spray adhesive. Just be careful with how much you put on the insulation as you can end up with an unintended frequency blocker at a high frequency. Possibly not noticeable to the ear, but just something to be careful with. If it were me, I would apply a full spray over the back of the BAD and a light spray to the insulation. It will still bond, but the insulation behind the holes won't be as coated. Or again, use some 1x# and just attach the BAD to the frame and friction fit the insulation.
Again, I'm not sure what the purpose of the frameless panel is for your specific case.
I haven't looked at building BAD panels for a while, but shouldn't it be 1/8" thick HDF or equivalent instead of 1/4" MDO? I guess BAD panels aren't Helmholtz, so maybe that doesn't actually matter. Are you planning on making square-ish 31 x 33 panels (1/2" holes with 1/4" between the holes with spaces that obviously won't have holes) or try to cut the "BAD" layout to something more rectangular? If you want to mimic the true BAD panel, you will want OC705 behind it since it is the spec'd 6lb density. Then again, the panels have somewhat evolved to some degree with a lot of DIY personalizations over the years.