velodyne dd12 or jl audio fathom?

The SVS PB 13 looks awesome - for movies the ports can be left open and the 20Hz output is outstanding - no compression WOW, however the group delay is a wee bit high for my liking for music (may sound plodding or muddy in kick drum). No worries though - stuffing the ports (changing to sealed) will make it more musical (lowers group delay at the expense of higher cone travel and distortion - but I prefer sealed subs to get a tighter sound which is better on transients).

Actually any of these subs look good on paper...now how will they match to your speakers....that is tough question...only you can tell that.

Yes the JL has impressive performance data - not perfect - some compression at 20 Hz but overall great value for money. Check out the HT Shack Subwoofer tests results I don't think you'll find a direct comparison with the DD12 but you can get the idea if you do a bit of research/reading.