I'd say your room. Your ceiling is 8' and width is 16. A multiple like this will make bass modes much worse. Bass traps at a minimum. You'll be amazed at the improvement in sound. Like the above poster states, room treatment. Until that is done it really doesn't do much good to try different components until your room acoustics are done as well as you can get away with. The "average" room has a frequency response of plus or minus 15db or more! No snake oil, hard facts of physics. The sound improvement by taming the room, if you can, is very substantial. You'll hear the improvement big time. I suggest going to realtraps.com and rives.com and reading. With those dimensions you have a serious problem in your bass and that will muddy up the mids and highs. Cheers
