I had the Velo CHT12, went to the STF-2 and now have the SVS-10. The STF-2 was a much better sub than the V-tighter, maybe not louder, but to me, a much better sound. The SVS is even tighter and louder than the STF-2, but not by much. Both are great subs. I would say go for the HSU, either the 1 or the 2.