Why Do Car Speakers Make a High Pitched Noise


When it comes to car stereo systems, the quality of sound matters the most.

You can have the best stereo installed in your car but buzz or whine coming from car speakers is the most frustrating and annoying experience.

But why car speakers start making high-pitched noises? Let’s find out.

The most common reason why car speakers make high-pitched noise is because of the alternator whine. Generally, this is caused by incorrectly grounded car stereo, by voltage interference in RCA cables. In addition, high-pitched noise from car speakers increases with an increase of the engine RPMs.

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Tip: Often, you can hear the unpleasant sound from car speakers when you connect your mobile device with a 3.5mm aux. The noise can be in the form of whine or static noise. 

The solution for this is simple, add a 3.5mm aux cable ground isolator to the wire, or use the original charging wire with the ground isolator already installed. 

My favorite wire with the isolator is Besign that allows you to connect the mobile device while keeping the sound without interrupting noises at the same time.  

In this blog, I will share detailed information about why speakers make high-pitched noise and a step-by-step approach to fix it. 

The good news is that you can fix this noisy issue without replacing expensive components like a car stereo, but the troubleshooting process can sometimes be time-consuming. 

What Is High Pitched Sound From Car Speakers?

It is the noise coming from speakers in the form of a whine, buzz, or a cracking sound. But to identify it correctly, you should know what kind of noise you are dealing with. 

There are two types of buzz sounds:

  • One is a low-frequency hum at 60 Hz and is non-irritating. 
  • Another is a high pitched noise ranging from 100-120 Hz, and it isn’t enjoyable to our ears.

The low-frequency hums are mechanically induced noise due to poor shielding. However, they are pretty easy to troubleshoot by just placing an ear close to each piece of equipment and listening to a humming sound. 

Why Do My Speakers Whine When I Accelerate?

The main reason for the speaker whine when you accelerate is an improper grounding of different components and interference in the audio signal. 

Let’s dig deep into them one by one.

Car Alternator Interference 

The leading cause of speaker whine is that the output of the car’s alternator is interfering with the head unit through power cables.

So as you increase the rpm, the output of the alternator increases, which improves interference, and the whine becomes louder. 

Poor Grounding 

Another reason for the speaker’s whine is the improper grounding of different components of the car stereo.

The main equipment that is more prone to poor grounding are amplifiers, car radio, crossovers, and equalizers. 

Grounding Loop Interference in Speakers

Ground loops occur when two components of car stereos are at different grounding potentials. This is the most common cause of speaker whine in the case of car stereos.

The difference in potential between two car stereo components produces an excessive current, leading to signal interference, which creates unwanted noise in speakers.

For example, when one component is grounded to the chassis and the other to the cigarette lighter, it can lead to the formation of a grounding loop. 

With acceleration, the voltage difference increases, and that causes more current and interference. In effect, speakers start producing high-pitched noise. 

Improper Mounting Of Amplifiers

Your car amp can be the source of speaker whine if mounted incorrectly. Here are some examples of improper mounting:

  • If the amplifier is mounted close to any other electrical component, then it can interfere with the amp signal and produce unwanted noises through speakers. 
  • The metal casing of the amp is touching the ground of the vehicle. 
  • Improper setting of gain controls on amplifiers can also cause hiss and buzz sounds. 

Poor Quality Signal Connection Cables

The problem is that the signal cables of low quality can pick up the noise along the signal path.

So the good practice is to move away from the RCA cables of your car from power cables.

In practice, that means, if you run the power wires to the amplifier on one side of the vehicle, run the RCA wires on the other side, not together. 

How to Check Noise in Speaker Wiring?

To test if the noise is coming from car speakers, turn off the car stereo and disconnect the speaker wire from amps.

Now start the car. If the problem persists, then your speaker wiring is good. The problem is with other equipment. 

How Do I Stop My Car Speakers From Whining?

As you already know, the main cause of the whining of car speakers is grounding. Changing the stereo ground location can fix the problem.

To change the location of ground wire, take the following steps:

  • Check behind the car stereo, and you will find 10 to 16 wires coming out of the stereo harness. 
  • Cut the black wire -12V (Ground wire) from the bundle carefully. This will break the connection between stereo and ground. Thus the stereo will not turn on. 
  • Now extend the black wire so that it reaches another grounding location, like a metal dash frame.  
  • To test the ground source correctly, you can use a digital multimeter.

Move the knob of the multimeter to continuity and make sure when you join leads, it produces a beep sound. Now connect one lead of the multimeter to the ground (near the door jam) and look for another grounding point on the dash cavity with the other lead.

When the multimeter beeps, you have found another ground location. Hook up the ground wire to this place either by crimping or any suitable method you can use. 

When you have connected the ground wire to the new place, turn on the stereo and check the whine from the speakers. 

This method usually solves this problem. However, if the problem still persists, you can use “Ground Loop Isolators.”

The ground loop isolators consist of an input, a transformer, and an output. The audio signal enters through input, passes through a transformer, and exists through output canceling interference.

How Do You Fix Alternator Whine in Speakers?

Below are a couple of steps that you can take to stop whining from your car speakers:

  • To eliminate noise from the alternator to the head unit, you can either install a noise filter between the alternator and car battery or install a noise filter in the power cable of the head unit. The alternator will still generate noise in either case, but noise filters block the noise, and speakers won’t produce whine. 
  • To fix the grounding loop interference in speakers, you can use ground loop isolators. 
  • Another method to overcome the grounding loop is to ground all the components at the same place to cancel the voltage difference. 
  • Properly mount the amplifiers away from any other electrical equipment. Isolate the amplifier from the car metal body by mounting it on a plastic amplifier rack or rubber washers. Don’t forget to set the gain of amplifiers correctly. 
  • Use high-quality signal connection cables and properly shield them. Run the signal wires down the opposite side of the vehicle from power wires going to amplifiers. Another practice you can follow is to align power wire and signal wire perpendicular to each other. You can also consider the option of replacing RCA cables with twisted-pair cables. 

Conclusion 

The whining in speakers is just the effect, but the underlying cause can be associated with any car stereo equipment.

The troubleshooting of whine in car speakers is a difficult task, but by following the above few steps, you should fix this unpleasant cracking sound forever. 

Martin

Welcome to ImproveCarAudio! I am Martin, and I love to write about everything related to car sound systems. I strive to provide the most accurate and helpful information about car audio through extensive research, as well as my experience with car audio installations.

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