ok here's the problem. my g/f bought a 12 and and amp, the sub is a 250w rms 500w max and the amp is a 250 mono. i hooked them up and double checked to make sure everything way right. turned it up green light and all... when u start to turn it up u can hear the sub hit a little bit but when u turn it up some more the sub will just booooommmmmmmm it will steadily rumble w/o ceasing until u turn the headunit completly off. no matter if u turn it down or anything it will just rumble at one steady sound... and then it does it sounds like shit, does anyone have any idea what could be wrong. or anyone ever had this prob ? let me know please!!!!!!!