How to fix a crackling noise sound on a car subwoofer

If you noticed your car subwoofer is make loud crackling noises when cranking up the volume, you probably have a bad ground. A bad ground always causes this problem with the car amplifier. To resolve this issue, find a good grounding spot on your car's chassis and get sandpaper and sand down the metal. Sanding down the car's bodywork will remove the paint, that can cause a bad ground. Also clean the ground terminal connections, using a damp cloth to get rid of any electrical static.