what i'm thinking is that the 8in sub in the 533-pt maybe can't pump out the bass in my large room with openings on two sides room (25x14x10), thus buzzing coming from the woofer in the sub. maybe it is more promenient in the left main bacause the sub fires on the side and it is near the corner, where as the right 533pt fires on the side into a open space. could it be that the 533-pt just can't handle big bass for a fairly large space (they can go down to 30hz though). maybe if i crossover the 533-pts at 40hz or 60 hz to a new 10in sub that would help??