Re: Rumbling from stereo need help!
( regarding the humming noise) Is the 2 subs powered by a aftermarket amp? If so, Double check your ground off the amp and make sure it is good, clean ( on raw metal, no paint) and tight and also make sure the power lines to the amp are not next to the RCA leads, at least 8 inches apart or preferably run on the opposite side of the power lines. As for the rumbling, it could be the crossover is adjusted improperly or a blown speaker. If its all factory then it could be a bad amp and speaker. Hope that helps.