Ford: 94 ford explorer premium sound system, pioneer cd player, premium sound system

Question
I just installed an aftermarket pioneer cd player and 4 4-way pioneer speakers in my 94 ford explorer.  The wire harness I have integrates the facory amp.  I am having a slight crackling in the speakers.  My question is how good is the facory amp, could it be causing the crackling, should I just bypass the amp, if so how.

Answer
Jeff you have to bypass or use a crossover your getting the cracking do to your factory radio is low input and your after is high out put. just go to your stero store  best buys,circurt city radio shack ect.and jet yourself a jumper. this should take care of your problem,