I will repeat once more my solution from turning a mid size (20 x 16) family room with all the acoustics of a Jr. High lunch room into a very quiet and useful space for listening to music.
I covered all the walls with acoustic wallpaper ($700). The stuff is made of fabric about 1/4' thick and goes on like normal wallpaper. Available in a variety of textures and colors and patterns from wallpaper stores. Then I did the ceiling in the lowest cost 1" thick Sonex foam tiles (another $700).
Oh yes, thick carpet over a heavy pad on a concrete floor finished the job.
Now the room is quiet, dead, and you can hear what the system is doing without much in the way of nasty early reflections. It works, it is easy, does not cost all that much, and has a high wife factor.
Frank Van Alstine
Anyone else ever try this, or is it too simple. I have done it to two different listening rooms now with excellent results in both cases.