Whenever I play my mp3s or sattelite radio in my car, the speakers crackle if I add a hint of bass or even turn them up very loud. I would say that it is the speakers, but when I play a regular CD or the radio it is fine. I have the external sattelite radio running on a wired fm signal modulator. The equiptment is all aftermarket. Pioneer stereo with kicker speakers. Please help.

 

it is the fm modiulator not the speakers
why not plug the xm radio using the cd changer port of the radio