I have a Velodyne CHT-15 and yesterday I calibrated to reference, set it to reference, cranked the pod race scene and went to my neighbours. It was cool, you could hear nothing from the movie, but MAN outside and in his home you could feel bass energy it was kind of creepy feeling. Just this VERY low rumble that was just felt (kind of like an earthquake). So he suggested I try spikes, which should decouple the sub from the floor. I was thinking of using a 3/4" sheet of MDF and putting spikes into it. Then attaching the MDF to the bottom of my subwoofer using the rubber feet on the sub or just some blue ticky-tac. Will this help keep the bass in a little? I don't expect to actually watch movies at reference -10db or -5db is usually the max I go, but I figured I would see what I could do so my neighbour wouldn't feel / hear anything. Good news he can't hear it! Next will actually be to see if he can still feel it at -10db if not great!