Definately something to look into

You can build a sub wall about 2 feet out, and place all the speakers (sub included) back there. Use an a/t fabric on the rest of the wall where there is no screen, and you're golden.

I was going to go this route, but you really need to put sound absorbing material in the cavity between the walls and it was just a bigger project than I wanted to take on. It is a great way to do it though.