Subaru Whining Noise Over Radio, Ray was almost right


After years of installing high power car audio systems, I have run into several new and used cars that produce a similar whining noise. The noise originates from the alternator and enters the car audio system at the amplifier inputs, not from the radio. The noise is not Radio Frequency, it is in the audio range similar to the 60 cycle hum from florescent light fixtures.

There are several inexpensive alternator noise filters available on the market that are placed on the radio or amplifier.

It can be heard even when the radio or CD player is not running since the amplifier is still running idle.