Skip to Content

Why Does My Car Stereo Make a Buzzing Sound?

Hearing a buzzing sound from your car stereo is such an annoying experience.

On most occasions, this kind of sound mainly comes out when you are playing music loudly or having a lot of bass. So what might be the cause of the buzzing sound out of the car radio? Let’s find out.

TedsWoodworking Plans and Projects

The most common cause of the buzzing sound in the car stereo is the electrical interference within the car audio installation. Another reason can be a blown speaker or poor ground connection to the car stereo.

As an Amazon Associate, ImproveCarAudio will receive a small commission from qualifying purchases made through the links in this article.

Tip: Once you have heard an annoying buzzing sound from your car stereo, you need to quickly identify the cause of the problem and how you can quickly fix it.

Helpful with the investigation is the voltmeter, for example, AstroAI 6000, which you can use to test all electrical connections and find potential shorts or interference.

In this article, I will trickle down through various aspects of why the car stereo produces a buzzing sound.

What Is the Buzzing Sound Produced by a Car Stereo?

The speakers of a car stereo produce sound in the form of vibrating, also known as buzzing, but in normal conditions, you cannot hear this.

When the car stereo is in excellent working condition, the buzz does not go to the loud level. However, when the buzz is generated to levels that can be heard, then there is a problem!

When the stereo is damaged or the connections are interrupted, the buzzing sound is louder than the typical sound of the car stereo. This is considered damage to the membrane of the car speakers.

Note that when the paper cone that forms the speaker develops a tear or a hole, the speaker is likely to produce a loud buzzing sound.

What Are the Causes of the Buzzing Sound in a Car Stereo?

Electromagnetic Interference

Even though this is uncommon on most occasions, if the power cables connecting the stereo to the battery are bunched together or run near the RCA cable, then the stereo is likely to produce a buzzing noise.

The noise comes out because you are mainly casing interference in the car stereo, thus generating a buzzing noise. 

Faulty Speakers 

The car stereo produces sound through the speakers. Besides, this is where the buzzing sound is produced. Therefore, it is advisable that once you hear the buzzing sound, head directly to where the car speakers are located and check if they are in good working condition.

Remember that you need to open up all the speaker coverings and visually check the speakers before you identify whether they are the problem or not.

Take your time and evaluate your speakers’ cones and the surroundings. Even the tiniest holes are likely to cause a buzzing sound in the car stereo.

As you continue using your car stereo, the speakers are exposed to wear and tear when playing music. You also need to understand that once your car speakers have rips, they do not work perfectly as expected.

The speakers’ cones are the most delicate parts that require excellent care to enhance the functionality of the car stereo. Once you identify that the speakers are good enough, you need to identify the possible problems.

To ensure that the speakers are okay, you can test them using a different source and listen to if they will still produce the buzzing sound.

Bad Ground Wires

The ground wires play a significant role in the well-being of the car stereo system.

Also, they have a significant impact on any car stereo that produces a buzzing sound. However, the ground wires need to be perfectly fitted for the operations of the car stereo.

Remember that the ground wires should not be too long and of the same size (gauge) as the power wire.

When the length of the ground wires is longer than expected, it causes an annoying buzzing sound through the car stereo.

Besides, the ground wires facilitate the operations of other essential components of the car stereo, such as the amplifier and the equalizer. This indicates that the system should have proper wiring to operate smoothly.

Note that when the wiring of the ground wires is appropriately done, it adjusts the quality of the sound produced by the car stereo. Conversely, when the connection of the ground wires is disturbed, you should expect the buzzing sound from the car stereo.

How to Fix a Buzzing Car Stereo

Service the Radio

Servicing the receiver is not an easy task, especially for newbies in the industry. However, before you begin doing anything, disconnect all the head unit cables completely. You can start by disconnecting the RCA cables before heading to the stereo.

In some cases, you may need to connect different car stereo to confirm if the buzzing noise is caused by the speakers or the faulty head unit.

Once you change the stereo and realize the buzzing sound is still coming out, the problem is with the speakers, and you have to service them.

If the buzzing sound produced stops, the problem is the head unit, and it requires replacement for you to get the best sound output.

Most people tend to be confused when identifying the cables. If it is hard to locate the speaker wires from the stereo side, pick the cables behind the speakers and try to identify them.

When the speaker wires are in contact with other cables (RCA or power wires), the chances of generating a buzzing sound increase.

Fix the Damaged Speaker Cone

When you identify that the car stereo speakers are damaged, you have no other option than to fix them unless you decide to replace them with new ones.

You can also fix the number of holes and rips in the speakers and ensure that the tears are relatively low.

Always be cautious while fixing the cones since they are very delicate, and you can end up destroying the entire thing.

Install a Filter in the RCA Cables

The best thing to do is install a filter within the RCA cables. The filter will significantly help reduce any noise generated by your car stereo.

It is vital to acquire an excellent filter with high-quality standards to execute the work, and the best I know is the Boss Audio B25N Ground Loop Isolator.

A good RCA cable filter can reduce about 80% of the noise caused by cables interference, especially from the power cables.

BOSS Audio Systems Ground Loop Isolator B25N noise Filter for Car Audio Systems

Upgrade Your Wiring Connectivity

Loose wiring can significantly cause interference that affects the normal functioning of the car stereo.

You need to ensure that every wire is perfectly connected to its exact point and tight enough to transfer the correct amount of electricity.

Check and confirm, especially if the ground wire is securely connected from the negative terminals of the battery to the vehicle chassis.

Also, ensure that all the cables connected to the battery’s positive terminal are firmly connected.


When you are done servicing every point that might result from the buzzing sound in the car stereo, run the speakers and increase the volume to identify if the buzzing sound still comes out.

This will help you determine if you have solved the problem or not.