popping from speakers??

everytime i turn my cd player up there is kinda like a popping/static sound comin from my dash speakers but after a few seconds it goes away but will still do it throughout playin some songs. it also sounds like the right speaker is louder than the left. what could this be? its a sony cd player but an old one. thanks

??????

They are blown. The voice coil sounds like, but I say they are smoked.

TAKE A MULTIMETER ,PUT IT ON OHMS AND SEE WHAT IT READS IF THE OHM MATCHES THEN ITS THE HEAD-UNIT

Are they mainly doing it when there is bass? If so check that you don't have the pos & neg around the wrong way. Short of that it sounds like they are either blown or not far off it. Check also by isolating each speaker off the head unit if it is only one speaker that is doing it or if it is all of them, if it is one or two only check the speaker itself or the wiring, but if it is all of them go straight to the back of the head unit and check the loom connection. If the head unit is a kenwood or a clarion (for example) the looms at the rear not connecting correctly is a common problem.