rumbling sound when voltage changes
I have a 100 watt - 10" black bazooka sub.
All has been fine for the last 2-3 years, but now I'm noticing a rumbling or popping sound, at times.
I thought it was bad connections, so I changed the wiring harness to a new one. Still the same. Then I swapped the 10" for one of my 8" powered units. The sound disappeared.
I put the 10" back in and the sound came back.
Recently I have notice a correlation between voltage changes in the vehicle and the noises occurring.
For example - when I change the fan speed, or when slowing down, or turing on the rear window de-fogger it happens every time.
Does anybody have any info as to what could be causing this?