Why is my car amp humming?
More often than not, when your amp is making a humming sound, it’s caused by dirty power, a bad ground connection, or fluorescent lighting.
How do I get rid of engine noise in my car amp?
If engine noise is your culprit, you may hear a whining or clicking sound. Its pitch will usually vary with engine speed. If this is the case, you can install an alternator noise filter on the power line between the battery and the alternator to minimize the problem.
How do you fix ground loop hum in car audio?
Grounding a head unit to a cigarette lighter instead of the chassis also can introduce a ground loop. The right way to fix the problem is to tear down your sound system and attach the grounds from components like the head unit and amp directly to the chassis in the same place.