I have never bought a sub. I do have some observations over the years having built quite a few on what to pick:
I find low Q sealed subs to blend with the room gain better than ported. Less group delay, no port noise. To me, they sound more precise and better controlled for music. If a HT or with DSP, the response can be mitigated somewhat and for a HT and si-fi special effects, maybe better to go ported to get below 25 or so. If you don't already have some DSP for the sub, I recommend looking at the DSPeaker Antimode products. I don't want DSP in my mains, but for the sub it is invaluable. I find smaller subs 10's or 12's blend with mains better. The more the easier to tune the room.
SVS and Rel seem to own the market right now. Rhythmic I think maybe should get more attention. Subs are actually not very difficult so I wonder how much better the above are over maybe a Monoprice? ( or Rel S over T) Several cheaper ones so each does less excursion may have lower distortion that one otherwise better one. Just a thought.
