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What Is the Best Noise Filter for Car Audio?

After installing a new car stereo in my car, I decided to take it for a test drive. I lower my car windows and turn up the volume. Everything is working well.  

When I plugged my iPhone into the aux, a whining and buzzing sound was coming out of the stereo. After doing my research, I have found that it is a very common problem and can be fixed by using a noise filter. 

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Here is the list of the best noise filters that you can use to suppress unwanted disturbances –

  • Best Noise Filter Under 10$ –  RECOIL GLIRCA (check prices on Amazon)

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

In this article, I will provide information about noise filters, why you need them, and will look into some of the best car audio noise filters available online. 

What Is a Noise Filter for Car Audio?

If you have purchased an aftermarket stereo or installed any other audio accessory in your car, you might have heard unwanted noise. 

Therefore if you hear strange whining noises, it’s time to get a car audio noise filter. 

A car noise filter is, also known as a ground loop isolator, is used to block high-frequency current coming out from car audio systems. Removing this unwanted noise ensures that your music gets through the entire system and doesn’t interfere with your listening pleasure.

A car noise filter is a circular magnetic inductor with wire wrapped around it and is usually made from a ferrite magnet.

Car audio noise filters are not expensive, and simple BESIGN Ground Loop isolators will cost you around $10.

In other words, after spending just $10, you can get rid of unpleasant sound and improve audio output even from the expensive car audio system. 

Best Car Audio Noise Filters

In this section, I will show you the best noise filters for your car audio. 

Recoil Glirca – Best Noise Filter Under 10$

It is a two-channel ground loop isolator designed to eliminate noise.

If you experience alternator whine from RCA connections of the head unit, then plug Recoil Glirca into the head unit. You will see that it works like a charm and eliminates noise. 

RECOIL GLIRCA 2-Channel RCA Stereo Ground Loop Isolator Designed for Audio Signals Eliminate Noise

What I Like About This Product:

  • Eliminates noise between radio and audio source.
  • You can use it with all portable head units having RCA audio outputs (including preamps)
  • Better Gain – It provides a gain of around 1.3 dB by using a small audio transformer.
  • It comes with 2 split-pin RCA connectors.

What I Don’t Like About This Product:

  • Eliminates only the ground loop noise of one amplifier.
  • Requires separate male-to-male RCA cable to wire it with another audio device.
  • It does not eliminate the noise coming from speakers.

ZVFOTN Ground Loop Noise Isolator – Best Noise Filter Under 10$

This portable ground loop isolator is specially used to eliminate humming, hissing, or buzzing noise coming specifically from car speakers, home speakers, etc. 

ZVFOTN Ground Loop Noise Isolator, Audio Noise Filter for Car Audio/Home Stereo System with 3.5mm Audio Cable, Eliminate Buzzing Sound, Black

What I Like About This Product

  • It is simple to use. Just plug ZVFOTN Ground Loop Noise Isolator into AUX port of car speaker or stereo. You also need an AUX cable to connect it with another audio source. After wiring it, you will notice an instant reduction of the speakers’ noises.
  • It is compatible. This noise filter can be used with car stereos, car speakers, home speakers, personal computers, Bluetooth receivers, smartphones, etc. Basically, the only requirement for the equipment is to have a 3.5 mm AUX port to plug in this device.
  • It does not reduce the bass and dynamic of the music. It works well with rock music.

What I Don’t Like About This Product

  • You cannot connect multiple audio sources to this noise filter.
  • It is designed for light car audio systems.

Boss Audio B25N – Best Noise Filter Under 20$

Boss Audio B25N helps you in eliminating the interference caused by ground loops. It had two male and two female RCA connectors. 

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

What I like about this product 

  • It is straightforward to install. Just connect the two male RCA connectors into the stereo. You also need a male-to-male RCA cable to connect it with other audio sources like an amplifier. To check the wiring diagram, click here.
  • It reduces background noise without disturbing the bass of your car audio.
  • It can also be used to eliminate the noise from the home and PC speakers.
  • Portable.

What I Don’t Like About This Product

  • If you are using a powerful sound system, this noise filter will not work properly.
  • Need male to male RCA cable to wire it up with amp. This cable is not included with the noise filter. So, you need to purchase it separately.

Kript Hifi Ground Loop Isolator – Best Noise Filter Under 20$

This noise filter is for audiophiles who want to listen to low-frequency signals up to 20Hz without a single distortion.

Kript HiFi noise filter only eliminates humming and buzzing noise due to ground loops.

If you are experiencing noise while playing music from your smartphone from the AUX port, then use this noise filter in between the phone and the car radio. 

Kript HiFi Ground Loop Isolator for Audiophile Low Frequency Can Reach 20hz Music Without Distortion

What I Like About This Product

  • The unique selling point of this noise filter is that it uses a larger permalloy transformer core which effectively eliminates distortion. 

Ground loops usually occur when the speaker and audio source utilize the same power source. This is most common in the case of home and car Bluetooth stereos. In addition, the permalloy design ensures the smooth transmission of sound by eliminating noise, and it outperforms silicon steel designs.

  • Compatible with any device that has a 3.5 mm AUX port.
  • Lightweight, easy to install, and portable.
  • If you hear noise while charging your device from the stereo but not when operating on the battery, this noise filter will solve the problem.
  • It can also be used for headphones to eliminate the noise.

What I don’t like about this product 

  • Only eliminates noise due to ground loops.

HEASEN Audio – Best Noise filter Under 50$

If you are looking for an affordable yet professional noise filter, this product is for you.

It is a four-channel ground loop isolator. It is designed for car stereo with ratings of up to 50 watts which means it is suitable for every car stereo used.

It has 4 RCA cables which means you can connect two audio sources using HEASEN 4-Channel RCA Audio Noise FilterThis noise filter is designed in such a way that shield ground on each audio cable is isolated from equipment ground. 

MagiDeal 4-Channel RCA Suppressor Noise Ground Loop Noise Isolator for Car Audio

What I Like About This Product

  • It is easy to install, compact in size, durable and smooth.
  • 4 RCA cables allow you to connect more than one audio source.
  • Each RCA jack and plugs are gold plated.
  • All the connections are corrosion-free.
  • Completely removes radio static, alternator whine, EMI, or hissing sounds.

What I Don’t Like About This Product

  • It does not eliminate unwanted noise coming from the car speakers.
  • Some customers also complain that after installing this audio filter, they feel a reduction in speaker bass.

MLDSN Universal Noise Sound Eliminator – Best Noise filter Under 100$

This four-channel noise filter eliminates the interference caused by ground loops. It has a nominal input power of 50 watts, and the maximum output power is 100 watts. 

What I Like About This Product

  • The audio impedance of this device is 3.5K ohms at 1 kHzDC, and the DC impedance is 100 ohms. This means it can be used with heavy audio drivers and amps.
  • RCA connections are gold plated which ensures corrosion-free connections.

What I Don’t Like About This Product

  • This noise filter is expensive as compared to other filters.

Yarachel Noise Suppression Cable Clips

Yarachel Noise suppression cable clips effectively eliminate any EMI or distortion.

You just have to put them on the wire close to the electromagnetic source. This will make the electromagnetic field more constant and lower unwanted noise. 

Yarachel 50PCS RFI EMI Noise Suppressor Cable Clip for 3.5mm/ 5mm/ 7mm/ 9mm/ 13mm Diameter Cable

What I Like About This Product

  • These cable clips are made from Ni-Zn ferrite plastic. They help create a uniform electromagnetic field around the wire and filter out high-frequency noise signals.
  • Convenient to use, simple, portable, and easy to install.
  • The performance of noise suppression clips is excellent, and they are very durable.
  • Clips can be used around various cables such as power cables, AV cables, data cables, etc.

What I Don’t Like About This Product

  • Clips are only effective to eliminate noise signals traveling in the wires but not into an individual component.

Why Should You Think About Getting a Noise Filter?

Suppose you have installed a new audio system or an amplifier in your car. When you turn up the volume, you notice a hiss or buzz-like sound. This is called noise. 

A noise filter filters out unwanted signals that spoil car audio output. As a result, noise filters are effective in improving overall sound quality.

Following are the leading cause of noise in car audio systems: 

Improper Grounding

Improper grounding is one of the main causes of noise in car audio systems. In any case, make sure your system is grounded correctly.

  • Is your grounding point near a noise source like an amp, radio, etc.?
  • Is the car radio antenna adequately grounded or not?

In most cases, a car antenna can be a source of noise, and if you suspect this, remove the antenna and play the sound.

If you stop hearing the noise, use a noise isolator or cable clips in between to suppress the noise. 

Alternator Whine or Engine Noise

The noise caused by power and ground wires connected to stereos is called alternator whine. If noise is caused by alternator whine, you will notice that it increases with engine speed. 

In this case, you can install a heavy-duty noise filter between the battery and the car engine. 

Noise Due to New Amplifier

Due to poor grounding or poor amplifier installation, you can start hearing a noise in the car sound system. To remove noise, you can install a good noise filter between the amplifier and stereo. 

Noise in the RCA Cables

RCA cables are used to carry signals between different audio components.

When these cables pass near a power source, the noise signals get transferred through them. This noise signal degrades the primary signal and thus produces unwanted noise. 

To avoid this, you can use noise suppressor cable clips around RCA cables. 

Noise while Connecting External Devices

When you plug your device in stereo AUX input, and it starts producing noise, you can use PAC Noise Filter between car stereo and audio source. 

This plug uses a proprietary audio transformer and filters signals between 2 Hz to 20 kHz. 


Noise problems in your audio system are very frustrating, especially when you have installed a new stereo and can’t wait to hear it.

Noise in a system tells us that something is fundamentally wrong. So it’s better first to figure out the cause of the noise and then use a filter to suppress it.