Hey everyone. Due to some echoing problems my space has, I'm going to be making 8 absorption panels for my living room in the next few weeks. I've watched countless videos on youtube, and there's one technique that I think will work best for me. It's seems to be the simplest, cheapest, and quickest. I'll be using 47"x23"x3" Roxul Safe n' Sound that I had to special order from Lowe's. I would've preferred to use Rockboard, but it's just not available in my area I guess. Anyway, the guy in the video seems to be using 2" thick material, in a 4" thick panel. He attaches a 2" thick spacer inside of the frame for the Roxul to rest on, so while the Roxul is flush with the front of the panel, the recommended 2" air gap is still in place behind the panel. This is my problem... Where I live, the Lowe's not only does not carry the Roxul I need, they don't a 5" thick piece of lumber for the 3" thick Roxul, to allow my 2" air gap between the wall and the back of the Roxul. So, since I'll have to use 4" thick framing for the 3" thick Safe n' Sound, would only a 1" air gap be sufficient? I really don't want to get into all kinds of weird cuts that need to be made, or have to buy extra materials to make it work. Simpler is better. Also, I'd really prefer not to have 8 panels sticking out from the walls more than 4" all over the room.