do me a favor... are you tapping it on the sides and such and it rubs? but you push down in the middle lightly and no rubbage. because i can go in the shop pull out an sx from a box and make a scratching noise if i wanted to. especially if it vertical not horizontal
what kind of box do you have and whats the port size/tuning? SX is a good driver
oh and clipping on that amp will blow the sub. make sure ur not cranking it and your source (cd, mp3) stays clean