Below90hz, I too am looking to upgrade my sub. I am currently running a HSU VTF2.3 that is about 4 years old. 12" sub with ports & plug, kinda the VTF-15's baby brother. Weird thing is that they spec out about the same except that the 15 has more power & plays louder. It is rare that I find the VTF2.3 runs out of headroom, but it does happen occasionally. In a 12x20x9 den that is open to the kitchen on a concrete slab floor(No Texas). Considering the VTF-15, CHT, & Epik. 66% movies, 34% music. Don't get me wrong, I love the sub I have, but wonder if I'm missing much down low, or if the alternatives will give me more body slam with movies. BTW, I am running a pair of classic Polk Monitor 10's w/Peerless tweeter & polk center & surrounds. Sorry, just went to a concert & fireworks show last nite! Got the bug all over again.