Subwoofer recommendations for mostly music

Hi everyone. Well having been a live sound engineer I have bit of a background in sound design and the major obtacle in subs is that what you really want out of them is the lowest octaves but if you seal the box it wont naturally occur without some eletronics because it does not naturally resonate so low, the responce naturally rolls off there unless its huge. The flip side is if you vent or band pass is that your responce is not so smooth and your driver has a tendency to over exert it self on the tuned frequency, making uneven playback. Obviously this effect has been mitigated by crafty designers. The only end around I have heard to this problem, though I havent demo them is by a company called baggend who designed a patented processor to allow for natural effiecient and smooth extension, unfortunately it is a very expensive set up. All in all it is hard to have your cake and eat it too. Maybe some of these passive radiater designs or push pull drivers make most sense?

I'm not sure if this thread is still being used but I came across it because of having the same issue as Oakiris - knowing nothing about subs and not sure if mine is working properly. I've owned the Onix UFW-10 for awhile but only recently hooked it up to my Cary SLI-80. I know I'm not supposed to "hear" the sub, but it just doesn't sound like it's adding much to the bottom end. I'm using it to complement my Silverline Sonatina II's. Any thoughts?

Look into having a custom made cabinet for the TC sounds LMS5400. It will destroy most of the overpriced stuff here.
Its an 18inch woofer that can run over 100db at 20hz with less than 5% thd.
Very linear.

Sub technology has changed alot since the start of this thread. Best subs for the money IMHO are:

Hsu
Sunfire
Martin Logan

In general, sealed subs sound smoother than ported subs. Avoid VMPS.