If you have to cover your ears because of a whining noise coming from your car stereo, a ground loop may be the culprit. It’s impossible to say for sure without looking at your specific car audio system, but your audio system may be suffering from a classic ground loop problem.

Ground loops occur when two components are grounded at locations with different ground potentials. This can create an unwanted current, which introduces the type of interference often described as a hum or a whine.

The proper way to fix a car audio ground loop problem is to ground everything to the same place. If you can't fix it properly, the solution is to use an in-line noise filter.

While there are many things that can cause unwanted noise in a car audio system, the biggest culprit is ground loops. This noise problem can occur when two audio components in the same system are grounded in different locations.