I found and solved the problem. And it was not the connector, at least not directly.
I opened my empeg to check the wires attached to the connector, because when I moved it, it would crack and pop.
Behind the connector, under the HD tray, it's the audio output connector. The wires coming out of the plug were bunched in an awkward manner under the tray, so I removed the try to fix them, and found out that one of the shield wires was broken off the connector, and was only making intermittent contact with the terminal. The other shield wire was about to break also, as I was just straightening the wires it broke off. So I decided that the bunching of the wires under the tray and the car vibration had broken off the wires.
So I just soldered the shield wires to their terminals and arranged the wires so they were not pressed by anything and now my problem is gone. I can shake and hit my empeg as much as I want and the sound is crystal clear, when before even by closing the door of my car would cause a terrible rasping sound.
I hope this helps anybody else who may encounter this problem. Check for vibration-weakened or broken cables, or even by vibration-broken wire insulation.

Calvin