I am planning to build a media room [home theatre] in ½ of my garage. I have room for up to 15 x 9 size. Due to the garage door tracks the ceiling would have to go from 8' to 7' at the rear or 7' for the entire room. I am leaning toward the sloping ceiling. How will that effect the acoustics? The 2nd question is should I use the concrete block wall on one side of the room or put up a Sheetrock [quiet rock or similar product] wall to match the wall on the other side. How will leaving the concrete block wall uncovered effect acoustics?