I have a pair of Infinity Kappas 6.5CS in the front powered by an Alpine 4 channel amp (FV-340) that's bridged to two channels. It's been working fine for months and all of a sudden, I got this very loud popping sound (more like a lot of successive popping sounds) when I was listening to the radio. I quickly turned off the radio ( I have a Pioneer Premier HU) and after it was off, it was still popping for a good second or two.
I noticed if I turned up the volume a bit, the popping would stop BUT, whenever I changed any setting (pressed a button) that required a momentary pause in sound (switching from CD to radio, changing preset EQ shapes, changing high-pass/low-pass filters, you get the picture) it would make a loud popping sound.
I am thinking ground, but I checked all the connections and everything is tightly bolted down. I grounded the amp to the rear deck and made sure I sanded it a bit. Why would it all of a sudden start doing this?