Acoustic panels...diy plus l+r wall different

[jeff5347]

Ok so I'm looking into making some acoustic panels. My first question is the insulation. I've seen ppl say OC 703 and watched a video with rockwool safe and sound. Curious on the safe and sound as it looks like 6 pieces 24x48 for 56 bucks but says for "interior walls and inside ceilings". Is this stuff ok to be in the open and breathed in. My other question is making them, I guess more due to the walls. My left wall is all paneling and my right wall consists of a bookshelf with doors under and then a fireplace followed by a panel wall. Do I make the panels for just my left side. I think this may muck up the acoustics. Curious on thoughts

 

[NBPK402]

Supposedly the Rockwool is not as bad to breathe, but when we used Roxul rockwool for our last HT I still covered it with fabric on all sides. I do know that Roxul is easier to handle as I did not have any itching from installing it like I would with fiberglass.

 

[Mike-48]

You might put panels on the R wall also at the fireplace, to help prevent slap echo in the back of the room. Also, some treatment of bare walls on both sides behind the listening seat. Untreated parallel walls cause slap echo, which can make the sound more irritating.

Consider looking for plans for panels that incorporate sound diffusion or reflection, not just absorption. ASC uses a few mylar strips under the fabric of their panels to avoid over-absorption of high frequencies. GIK has a plate on the face of their Alpha line; RPG puts plates under the fabric of their BAD panels. The only time I ever felt I had overdone acoustic treatment was when I used a lot of purely absorptive panels. So while I'm not an expert on panel design, I think that is definitely something to consider.

 

[j.man1503]

I had the same question when building the panels for my theater. I ended using rockwool, given how cheap it was, although I did opt for the rigid rockwool and not the Safe n' Sound you're referring to. I covered all front and sides but not the back, as the back was up against the wall. In terms of safety, should be the same though. Rockwool is safer than cotton, see the studies listed here.

I agree with Mike-48 about slap echo. The main problems that you should be looking to eliminate, in this order, is
1. Bass trapping (treating corners)
2. First order reflections (treat F.O.R. of the LCR esp.)
3. Slap echo (as Mike-48 said, treat parallel walls)