Tri T, I really doubt that your an install tech, if you are you much work at best buy; and your answer is probly why because you have no clue to what the hell your talking about.
Remove the sub from the box and check the wiring of your voice coils, they might be wired back wards. Also check all wiring of all and any speaker wire from the amp to the sub. The last thing you will need to check is the rca wires from the stereo to your amp. Make sure they are plugged in all the way.