What floor-standers do you have? When you put it under your TV, did you angle it up? When you have it on top of your TV, is it in-line with your ears? If not, have you tried tilting it so that it is in-line? Also, place it as close to the front of your TV as possible to minimize diffraction from the top of the TV. Is the level set correctly? There are users on this forum that have huge home theatres (4000 cubic feet+) and manage just fine with a single VP150 so my feeling is that a second one would be a waste of money.