I am running about 600 watts to it from a diamond 600.2 and I did half ass it with the glue there at the end. I am pretty sure that it is the port that is vibrating, like I said it only does it on deep bass notes and at high volume. The box is almost exactly what the spec sheet says, about 2.1 ft^3 at 29 htz. the 1200.1 diamond is on the way with that kind of power should I just put it in a sealed box? I know I can build one of those.