I don't use subs with my main listening system as my speakers are 3 db down at 20 hz, but I do augment bass for video use and run a pair of the Hsu VTF15H Mk 2 for home theatre use, and agree that they are excellent. Hard to get more bang for your buck than that.
Strongly suggest that those who can afford it get a matched pair rather than a single.
Strongly suggest that those who can afford it get a matched pair rather than a single.