I'm looking to update my subwoofer to something that not just go "wooooooo" in the lower regions, but actually has some punch to it. I'm mainly looking for a sub for movies, but since I listen quite a bit to music as well, it'd be good if it could perform really well in this area as well. I live in an apartment and my living room is 13.8"x13.8"x8.8" (hopefully I got those measurements correct - I'm from Sweden and more used to metric values ). One issue that concerns me is the size of the sub. I would rather have a small box giving great sound than a big box giving superb sound. Anyways, I've been looking at some of REL's offerings, namely the Stampede and the Q150E, but since I started reading suggestions on this forum, the BK XLS200 has emerged as a possible winner. Problem is (of course) that I can't test listen this one, so I will have to go on what I read on forums such as this. Therefore I'm looking for as much information and suggestions as possible on which way to go. So if anyone would like to give me some pointers on which sub to invest in, I'd appreciate it a lot. The subs that I'm mainly interested in are: BK XLS 200 - small, good with music, but maybe not so much power with movies? Q150E - small, good with music, also good with movies? Stampede - bigger but still not too big, great with music and pretty good with movies? Is this a reasonable summation? I've also looked at slightly larger subs and there I have two contenders: SVS PB10-IBS - almost worshiped by buyers on forums, but is the power of this sub to much for my apartment? Would I really be able to use the depths from this without being evicted? BK Monolith - better than PB10? Too powerful for my apartment? I know that the prices on all of these are quite different, but since I'm willing to spend up to about £630, I'm looking into all possibilities (as long as the box isn't too big - which it almost is with the PB10 and Monolith). Any comments/suggestions will be read and considered carefully.