I just got a fairly nasty sub (woohoo!). However, I'm in a basement with a concrete floor, carpeted in the HT area. Unfortunately, whenever I turn up the volume, the upper floor shakes more than a bit, while the response in my HT is much more ... restrained. Does anybody have suggestions for improving bass response (maybe so that if the upper floor has to shake, that I at least get some of the oomph in my chest?) Thanks in advance.