I have my home theatre set up in a basement in an alcove with concrete back and outer walls that come out about 6-7 feet, then it opens up into the basement. The ceiling is a suspended ceiling. I want to improve the acoustics and secondarily wouldn't mind decreasing sound to the upstairs. I don't want to do dry wall because I prefer not to make the room that much smaller. I had wondered about building a frame to hold somesort of material that could act to improve acoustics, any suggestions/ideas?