Well, I don't know about any of you but I am certainly confused!
I have only 1 place to place my M80's. It sounds like to me that the bass you are now hearing is from the ports out of the back of the M80's now that they are closer to the walls. I understand sub placement having an effect because it picks up the walls and floor differently in different places. Seems to me a 300 watt ported sub should be heard WELL even if the mains are placed on your head.
I'm NOT convinced!
Bob, I thought the same as you. But since I have Google'd subwoofer placement and watched axiom video on subwoofer placement, seems to me (although, I'm proof I don't know alot) that speaker placement is absolutely critical.
Also Bob, since you're a PA guy, I did find this article by Peavey,
http://www.peavey.com/support/technotes/soundsystems/boundarycancellation.cfm
