I just built 6 DIY panels like the ones on GIK accoustics. I have 1 4"2X4 panel in each corner and 2 panels for the first reflection point. I actually graphed the room's response showing before and after. The results are striking, in my opinion. I could send you them if you like. I could also hear the difference as well. Listening to 2 channel stereo is a whole new experience now.
My dedicated room is about 13'X30'. I was told that the optimuum number of traps in a room my size could be up to 16!! I am not that obsessed, but I might want to add a couple of more in the furture.
If budget is a consideration, go the DIY route. It would probably cost you only $30 per panel. Also, be sure to check out AVSfourm - Glenn, the owner of GIK, is a frequent poster in the "Dedicated Theater Design" room.
