You NEED to go check out HSU subwoofers. they are cyclinder in shape and go more vertical than out (if that isn't a problem). Their cost is comparable to both of the above mentioned, but handily outperform them both too.
Sunfire True Sub Jr. VS. M&K VX-100
I need a compact sub and was wondering if people had any thoughts as to which one of these is better? I am mainly interested in finding out which one is better for music, although home theater is a small part of the equation as well. My room is large (cathedral ceilings etc. but the listening position is barely 8 feet from the speakers). My main speakers are PSB Stratus Bronze (which go down to around 40 Hz). Also, because of severe space limitations I CANNOT consider full size subs. Input on the True Sub MK II as well would be useful. THANKS!!