I have read bad things about the Velodyne VX line. I believe the CHT is better and then you get to their good subs. But the consensus seems to be if money is not an issue - go with SVS or HSU.

I have a Velodyne CHT-8 ($175 with shipping). It is ok but I haven't really worked at positioning it. It is supposed to be decent. The VX line was supposed to be poor.

M22s, QS4s, M2 center, Hsu stf-1.