One way to fix your problem is to completely treat the room with "effective" bass traps, nothing less than 4" thick will do. Treat all 4 corners and the ceiling/wall boundaries as well. The wall behind the speakers would be best treated with bass traps as well. Don't completely cover any surface or you will "deaden" the room too much.
Two bass traps behind the listening position will also help.
You should end up with 10 traps in the room when finished. I have 12 traps (from Real Traps) in a room almost the same size as yours and it really sounds good.
Two bass traps behind the listening position will also help.
You should end up with 10 traps in the room when finished. I have 12 traps (from Real Traps) in a room almost the same size as yours and it really sounds good.