01 ford expedition

Is this problem appearing after you listened to the stereo for awhile or did you just get it and that's how it sounded when you bought it? In any event I would check at the subwoofer wiring to see if anything was disconnected and back trace to the fac. amp and to the radio. That may solve your problem. Otherwise I would just go aftermarket if your budget allows it, you'lll get much better sound. Maybe start by upgrading your fact. speakers including the sub and then maybe the next step should be a deck but definately speakers first. That's my $.02. 1 luv!