Ruulbreaker

Hey guys, I'm having issues with my 06 Cobalt. Very randomly when i am listening to my stereo, the volume will suddenly jump up as if someone cranked it up to 11, and then it will just go back to normal 1 second later. It seems the car is satisfied with scaring the crap out of me.
does anybody know where i can start to attack the issue? I'm thinking maybe a ground, but i am open for ideas first.

2wd-K5

do u happen to be driving? cobalts have a feature that turns up the radio as you go faster down the road to cover up the road noise

truckboy

check what your alternator is putting out 2nd what gauge is the wire between your alternator positive/ground of battery and power to trunk (did you sand the metal around your ground??) also what temp is the outside where you live all of these factor could be causing your problem