[jeffman2121]

while the resistance on the the sub might not be set right with the amp, say you have a 2 ohm sub and you have your amp wired at one ohm, that would be bad, that or if its more of a popping sound that does means its being pushed to hard, so you could fine tune the adjustments on your deck or you could fine tune and or unbridge your amp if it is bridged or put it in a sealed box