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How to Install a Noise Filter on Car Stereo?

If you want to reduce the amount of noise that comes through your car stereo, you can install a noise filter.

A noise filter is a simple device that goes between your stereo and the speakers, and it helps reduce static and other forms of interference, but how to install a noise filter in the car? Let’s find out.

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To install a noise filter, remove the car radio and connect the noise filter to the power and the battery wire. Some noise filters also have ground wire that needs to be connected to the chassis behind the stereo. After the noise filter is connected, install the car stereo back in place and test it out.

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

Tip: As a first step, you can try to reduce noise using a ferrite core filter. 

These filters are relatively inexpensive and can be found at most electronics stores. But, more importantly, they do not require any cutting or disconnecting of the stereo wires.

If the ferrite core filter does not eliminate the noise, install an inline noise filter. For example, Install Bay with either 30 or 50 amps. Do not use 10 amp because this is not enough for the car stereo.

In this article, I will show you how to install a noise filter on your car stereo to reduce static and other forms of interference.

How do I install a noise filter in my car?

The first step is to pick the most appropriate type of noise filter for your vehicle. There are two different types of popular noise filters, and both may need different setups.

The first type of audio isolator is super easy to install in your vehicle, and there is no extra setup needed. It is small and black and looks a little like a battery. It needs to be plugged between your car stereo and whatever device you are using to play music out of, whether a phone or a speaker. This is literally all that needs to be done. Easy enough!

If you listen to music from the phone like I often do, you may need to use Besign Noise Isolator. I am using it as an additional filter and do not have problems with strange sounds.

Besign noise filter is really cheap, and it works well for its price.

BESIGN Ground Loop Noise Isolator for Car Audio/Home Stereo System with 3.5mm Audio Cable

The second type of noise filter is a little more complicated to install and may differ between different car models, so be sure to have your handbook ready.

These filters come with red, blue, and black wires. The red and blue wires plug into the ignition wire that is inside the car stereo, while the black connects to the ground wire. And there you have it, crystal clear sound!

One noise filter that in my opinion is the best and can be installed permanently in the vehicle, and I recommend, is the BOSS Audio Systems B25N Noise Filter. It is especially good if you have installed an amplifier or weak ground connection.

Although it requires a little more wiring work and is a little more expensive, its installation is easy, and the results are great. I have added a Boss filter to my car before, and all weird buzzing noises have disappeared. It is also available on Amazon, and if you would like to get rid of annoying sounds forever, click the above link and check the latest price.

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

The function of a noise filter is simple enough. They come in a variety of different forms and shapes, and some require different methods of setup. For this reason, it can be a confusing bit of a kit to get the hang of using. It is really crucial to fit them correctly, or they will not have the desired effect, and you will still hear that pesky interference behind your audio.

But what actually is a noise filter for a car stereo?

A noise filter, also known as a noise isolator, works to eliminate background and engine noise to achieve a clear, uninterrupted sound.

Buzzing noises and whining noises can be heard when several audio sources use the same power source. The unwanted noise is able to travel through the ground wire and manifests itself as a white noise that can be heard through your speakers.

The noise filter is used to reduce this interference, in order to leave clean sounding audio behind.

The noise filter blocks the current of the loud, buzzing noises, which leaves only the pleasant sound of your music to play through your speakers!

How does a noise filter work?

Time for some science. A noise filter, or EMI filter, is fitted with components that allow only low-frequency currents to pass through. The buzzing, whining noise is of a high frequency, so it is blocked by the filter and unable to make any sound. The reason the sound exists, to begin with, is because of an excess of energy. The noise filter sends this excess of energy into the ground wire, rather than letting it out through your speakers.

After the noise filter has completed its task, you are left with crystal clear audio, so sit back, relax and crank that radio up!

When do I need a noise filter for my car?

So, we know what a noise filter is and how it works, but how do you know when you need one. It is true that there can be a variety of reasons why your car stereo is producing unwanted background noise, so it is important to identify what the problem is straight away.

If you go to your car, turn on your radio, and there it is! It could be a buzz, a whine, or a crackle. The audio in your vehicle is being compromised by static and noise.

You have created a ground loop in your car. When the car stereo is connected with an auxiliary cable to an audio device, such as a phone or speaker, and also to the same power source this is when the problem occurs.

But luck is at hand! A noise filter is a quick, easy fix for this problem, and you will be back to having high-quality sound playing from your car stereo in no time.

Related Questions

What if the noise filter does not stop the interference?

If a noise filter does not stop the interference, then either the noise filter has been installed incorrectly, or your problem is not with the car sound system but something external.

First, check that you have installed the noise filter correctly, making any necessary adjustments for the type of noise filter you have purchased and the make and model of your car.

It may be helpful to look over your car’s handbook and thoroughly read any instructions that may have come with the noise filter itself.

Secondly, if you are certain that the noise filter has been installed correctly, then it is time to further investigate the problem and try to locate where the excess noise is coming from. The best thing to do is to turn your engine off.

Can you still hear the noise?

If you are able to still hear a whining, buzzing noise, then unfortunately you have a problem that will not be fixed with a noise filter.

Your next step will be to really listen to the noise and find out where it is coming from. It may be difficult to locate exactly where the noise is coming from.

To aid with this, noise deadening material may be used to help you pinpoint exactly where the problem is. Once you have found the problem area, you can either kit it out with the material to mask the sound or conduct further research into how to fix this problem.

Does a noise filter only work with car speakers and stereo?

No, definitely not. Noise isolators can be used in exactly the same way for your home audio devices as for your car stereo.

The exact same method of installation is needed. Simply plug the device in between the AUX cable and the power source, and it should solve any audio problems.

Will a noise filter affect the quality of sound?

A noise filter will not affect the quality of sound coming from your car audio. This is what makes them so useful. It will only improve the quality as it gets rid of any background interference and white noise.

It has no adverse impact on sound quality, so you can install your noise filter without any trepidation about comprising quality!

Overall, a noise filter is the quickest and simplest solution for fixing interference on your car stereo. And as you have seen, they are relatively simple to install with little setup required. So next time you hear that pesky buzzing sound, you know exactly what to do!