I bought a 95 Explorer Limited and I am very pleased with it, even though it has 100,000 miles. It has the JBL sound system. However, the right rear door speaker hisses and pops periodically and then clears up. It does it whether I am using the radio, the CD or tape. I can turn the balance and fade to the left front and it still hisses and pops. Even if I turn down the volume all the way down, it hisses and pops. Is it the speaker or amp? What's the best fix? What is the best way to remove the speaker or amp, if necessary? Any assistance would be greatly appreciated.