I bought two brand new 12'' alpine type r subs. I have a rockford 700x which gives me 350 watts to each sub. 2 weeks after i bought the subs one of my sub kept rattling and the blew. and now 2 days ago my other sub is now rattleing? why is this happening? is it the connection or just overpowering the subs? I listen to trance and Drum and Bass . what do you recommend? What can it be?