speakers popping

For the last 2 weeks my speakers have been popping.  Only when im in idle or driving at low speeds.   On the highway it doesnt pop and while the car is off and the stereo on the speakers dont pop.  

Im just curious to what this could be.  I have 2 amps running highs only.  I also have a new stock battery. 

What do you mean by "pop"?

Its a high pitch pop.  It doesnt sound like a thump.  Its almost like a loud spark.  very loud.   Sometimes the whole system will act like its going to shut down then for a super fast sec then goes back to normal.   But if the car is off and the radio is on no problems.   only when the car is in idle.

This has never ever happened before.     It comes from all speakers.  Its usually each speaker at different times.  Like if it goes in rotation.  sparking all speakers. 

The first thing I'd check are all the grounds making sure the ground return resistance is less than one ohm, including for the head unit.  Make sure no part of the audio system is near the vehicle's ECU... what kind of vehicle is it? 

Its a 2006 dodge charger RT.   The battery is already in the trunk.  I believe i ran all rca's on the oppposite side of the power cable runnin from the front to the rear.

Also i have had the same head unit for 5-6 years now.  Never had this issue.  all grounds are mounted in the same location as the battery neg.  Amps have been in the car for atleast 2 years now with the same setup.    I plan on redoing my whole setup i just hope this wont happen again.   Im going to rip everything out and redo everything!

I ran 14-16 guage speaker wire the first time around.  Plan on doing 12 guage this time or maybe 10 depends if it will fit.