I'll tell you this much from years of experience, and that's that any of the top rated more accurate audiophile subs out there, properly setup, calibrated, possitioned, integrated, balanced with the seats and rest of the sytem, etc, will sound immensly better than even the most expensive highly touted sub(s) which isn't set up correctly!
There are many many good candidates, as long as the bass output is enough for the room/system it's used with!(e.g., enough bass for the set up). Most of the "A rated" subs', and even "B" for either music(if that's your use) or HT(if subs in that category apply).
I'm sure many people will associate woofers from companies like Rel, Bag End, Entec, or whatever other music sub comes to mind for audiophile playback. But I can easily think of subs like Revel B-15, M&K MX5000, Paradigm Servo 15, Infinity MTS woofers, maybe Velodyne HGS18, Thiel's woofer, Genesis's THX woofer's,
Wilson's way too expensive woofer, Wise Profounder's woofer, Earthquake's Supernova 15, etc, etc, and many others, that would be sonically superb in most any HT/music system when set up/calibrated properly!
I'm in favor of thinking that, at least for music, all things considered, with a good sub with a good high "Q factor"(e.g., tight well damped woofer), set up correctly, you should be able to get some sonically superb results from many of the offerings out there! I think there's not just "one sub" to be had is all I'm saying
