A suspended floor makes a HUGE difference. When I had my HT set up in my main floor family room, all the subs I tried out (SVS PB10-NSD, Energy S10.3 and even my first sub, a relatively modest DefTech ProSub 200TL) gave good massages.
Based on experiencing my PB12-NSD together with my buddy's MFW-15 in my basement set-up, I'm pretty sure that what I really need are dual ported subs, and I would love to get my hands on either the PSA V1500 or the RA Echo 15, but until the CDN dollar gets closer to par, that ain't gonna happen.
Anyway, enough side-tracking about me. Congrats again on the new sub! I'm looking forward to reading about the next one...
Never gave a cement slab floor a thought. I guess many people on here have some wood floors suspended. Here in south Florida we have concrete floors and no basement. So I guess that's why it's harder to shake stuff with no floor movement.
To the OP, nice sub you will enjoy 2 much better.