Hopefully someone can chime in and help me on this. Currently I am having a issue that is driving me up the wall. Anytime I turn off or on my reciever, I get a pop noise coming from both the subs and door speakers. I have tried troubleshooting this issue by making sure my amp grounds are tight (which is located under my driver seat under the carpet and also sanded down to make great contact with metal). Also also the issue still exists when the RCA cables are unplugged on both the 4-channel and mono amps. I just don't understand it. Currently here is a list of items I am using:

1. Pioneer AVH-P8400BH DVD Receiver
2. Infinity Kappa 680.9CS 6x8 components sets
3. Alpine PDX-M6 mono amp (Pioneer GM-D8500M mono amp died)
4. Pioneer GM-D9500F 4-channel amp
5. All Monster Cable speaker wires (twisted style)
6. High quality Stinger RCA cables

If I left something out please let me know and I will try to clarify or found out. Thank you for anyone who can help...

 

It's possible it could be a grounding issue because both amps pop WITHOUT RCAs is all I can figure. Where does everyone ground their amps at? I have a amp under each seat, but they are both grounded at a central location under the driver seat. There is already a grounding point under the drivers seat that connects to a module of some sort, so I just used that.

 

Try switching the order in which the grounds are stacked on each other. In other words if the lower powered amp is grounded first and the higher powered amp is stacked on top of that ground then switch the order. ground the high power amp first then the low power amp.

if that fails. disconnect one amp at a time and see if it persists

 

There was something wrong with the amplifiers because once switched to a different brand of amplifiers (Rockford Fosgate), then the problem went away.