There's a HUGE null in the middle of my room, right where my listening position is. Now, I was using 2 speakers and no sub, so I'm assuming that the speakers were canceling themselves out. Furthermore, it wasn't just on the horrizontal plane, but also on the verticle plane. When I sit down, the bass comming from the speakers is not nearly as loud as when I stand up, the difference is barely 1 foot. So, I'm going to get a sub (parts express DVC 12 in a 2.0 cubic foot box) when I order a pair of HE10.1s. I found the best place for the sub (by moving one speaker, while the other was disconnected, to the center of the room and walking around to see where I get the loudest bass). Would I still have the cancelation problem with the sub? My room is about 14X11X7. Xover would be about 80 hz.