SVS PC-4000 subwoofer (music only)...

Hi there all I can say is I Have had great experiences with SVS like many people I'm sure... I have always went with the sealed boxes. The particular model you reference I only remember reading bad reviews about. I have zero personal experience but that is what I read about it. As for bass extension under 20hz I have to think the PORTED boxes in the SVS line are the only ones that will reliably do this. When I listen to music I think rap is the only one I think of that would really require digging deep. I dont know that the other genres really make use of it. You're also not necc looking for that rumble you would in music as you do in home theater. I can tell you when I play rap I get to discover all my room modes running dual svs SB ultra 16s

I had an earlier version of one of SVS's cylinder subs.  It was OK, but I couldn't get past how big and ugly it was.  I prefer sealed subs.  Unless footprint is really an issue, I'd look at one of SVS sealed subs, better yet, get at least 2, preferably 4.  For music, I'd look at Rythmik first.  For sheer output, take a look at Power Sound Audio (started by one of the founders of SVS).