I got a probelm with alternator whining,now i hooked my system up all was good i went to extend my rca jack to give extra space for when i messed with hu i had slack in the trunk so i had to pull rca a little, went back to hu pullit out and BAM feedback so i thought it was the wires in back of hu i messed with them to no help no help plz noise is annoying
check your head unit ground. move it to a different ground location.
the RCA could have been damaged, causing a break in the cable or shielding.
there could be a loose RCA connection at the amp or head unit
the RCA could have grounded out and damaged the head unit causing the noise you're hearing. this happens frequently when people mess around with electronics without pulling the battery cable first.