mdrew, check out the SVS or the HSU... They do have some kick butt bass. I must warn you though the auto on function does not really work good at low level. You have to turn the gain of the sub pretty high before it will kick on at low level. With the gain set at high, the bass becomes overpowering. You just have to experiment with it. With my experience I always turned the volume loud enough to wake up the sub then I turned the volume down to the desired low level listening.
Actually the best bet is to get a Radio Shack SPL meter and calibrate your speakers... I'm pretty sure there will be more knowledgeable people other than Alan that will chime in to assist you. Good luck!
