I have a Boston PV1000 sub, 1000 watts continious. For such a small little sub, it'll really reach down and move some air. Only problem with this thing is that its much to happy to dance around and literally jump around when the bass gets heavy(LOTR beginning). I tried the velcro patches, no luck. I tried a bit of cloth under it to soften the thud when it "lands", again this was not cuttin it. I finally bought two bags of lead shot(25 pounds apiece). This worked okay, but when the bass got heavy, the shot would rattle. So, I called my uncle up. He owns a CNC shop and designs and makes progressive dies. He's got gobs of big, thick heavy steel laying around. I asked him to keep an eye out for a 12x12x2 plate of steel that I might have. He called me today and told me to drop by and have a look at a slab of steel. Its 12x12x2, just like I wanted. And its DAMN heavy. 100 pounds or so I'd hazard. Put in on top of the sub(on top of a big slice of craft/paper-cardboard stuff), leveled the sub up and fired up a mp3 called "Bass and Drum Armegeddon". I ripped it at 320kps, so its pretty clean. The sub now transmits much better, no shot buzzin away. And best of all, its not dancing around. My uncle even polished it up for me, and drilled two "grabbers" into the top, so I can attach a rope to lift the slab. I'll attach this thing to the floor with bolts when the new house is done, but for now the big weight does just great. I now have new rattles to find and deal with in the house...YAY!