Has anyone had any experience comparing the subjective performance of one woofer per side verses two woofers per side (placed vertically)? I have recently built new woofer enclosures with two units per side, and they sound a bit boomy compared to the single units I had before. I don't know if its because the second woofer is so close to the floor (3 or 4 inches), or because I used one large enclosure instead of two sub-enclosures. The two ports are front mounted and also next to the floor (about 1.5 inches). Anyone have any comments? Thanks!