mtx jackhammer

Ive had this build for a while now. 2 MTX JackHammer JH4512-04 12" 4-ohm subwoofer and a Pioneer 800w GM-7300M Mono subwoofer amplifier 360 watts RMS x 1 at 2 ohms. I was told to get this by some people so thought it was good at the time and for my wallet. I put it in a 02 focus had some...