Identify and Fix Issues With Your Car Stereo Speaker

Alternators are often the culprit—but not always

By
Jeremy Laukkonen
Jeremy Laukkonen
Jeremy Laukkonen
Writer
  • Shoreline Community College
Jeremy Laukkonen is automotive and tech writer for numerous major trade publications. When not researching and testing computers, game consoles or smartphones, he stays up-to-date on the myriad complex systems that power battery electric vehicles .
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Updated on July 8, 2021
Reviewed by
Michael Barton Heine Jr
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Reviewed by Michael Barton Heine Jr
Michael Heine is a CompTIA-certified writer, editor, and Network Engineer with 25+ years' experience working in the television, defense, ISP, telecommunications, and education industries.
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If you hear a whining noise while listening to your car stereo, don't assume your sound system needs to be replaced in the near future. Car speaker whine can often be fixed without replacing any expensive components, such as the head unit. Still, it can be time-consuming and challenging to track down the source of the problem.

Speaker Whine From Alternators

One common cause of speaker whine comes from the vehicle's alternator. If the noise changes in pitch or intensity when the engine RPM changes, it's probably some type of engine noise, and interference from the alternator output is a likely source.

The issue is that noise from the alternator is getting into the head unit via the power cables. You can deal with the problem in one of two ways:

  • Install a noise filter between the alternator and the battery.
  • Install an inline noise filter in the head unit power cable.

In either case, the alternator will still generate noise but it won't be able to get into the head unit and cause the speakers to whine.

A Human Finger Touching Music System In Car
Teerapat Seedafong / EyeEm / Getty Images

Non-Alternator Engine Noise Problems

If you have an external amplifier, you can pick up other engine noises that don't have to do with the alternator. They won't necessarily be whining noises, but they can be.

In this case, the problem almost always has to do with a poor amplifier ground, which can be fixed by ensuring that the amp is properly grounded. In some cases, you may also need to isolate the amp or install a noise filter.

Other Noise Problems

Most of the components and wires in a car audio installation have the potential to introduce unwanted noise, so it can be difficult to track down the culprit. If your speakers only whine when you're listening to the radio, but not when listening to a cellphone, MP3 player, or CD, the problem is somewhere in the antenna or antenna cable.

Patch cables, ground wires, and other components can also pick up unwanted noise. In the case of speaker wires and patch cables, fixing the problem by repositioning them so that they are far enough away from power cables and other potential noise sources. Ground issues are often solved by cleaning the ground location to ensure a solid connection.

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