I can either do 22'l x 12w x 6.5-7'h or I can reduce the length to 17' x 12w x 6.5-7'h. I prefer the longer room, but I was curious which one would be better acousticaly and how much better would it be? Would putting on (22') or taking off the 5' (17') be a huge difference either way? My ceiling has two air ducts that run lengthwise across the whole ceiling on each side. Each air duct is 3' feet wide and the height from floor to ceiling at this point is 6.5 feet. The remaining 6' of width inbetween the two ducts on the ceiling is 7' in height. I would prefer to put the room at 22' in length, but if it will be that much better acousticaly at 17' in length considering the other dimensions I might consider doing that. What are some opinions on this?