What Are Crossovers For Car Audio? 6 Must-know Information

When it comes to car audio systems, achieving optimal sound quality is a top priority for many enthusiasts. One key component that plays a crucial role is a crossover.

In this article, we will explore detailed information about crossovers and understand their importance, functionality, and different types. Whether you’re a seasoned audiophile or a car audio beginner.

This guide will help you catch the basic of crossovers and make informed decisions for your car audio setup.

Introduction to Sound Frequencies

When we speak of sound frequencies, we’re referring to the speed at which sound waves oscillate or vibrate. This rate of oscillation is measured in Hertz (Hz) and the hearing range of humans is from 20 Hz to 20 kHz. Normally, these frequencies divide into three types: low, mid, and high frequencies.

Low-frequency: You can imagine the bass you feel pulsating through your body when you’re immersed in an EDM or hip-hop track.

Mid-frequency: These fall within the range of 250Hz to 2kHz. They include most musical instruments and vocals.

High-frequency: These usually above 2000 Hz, give the music its clarity and sharpness. For example, you can find them when you hear the twang of a guitar string or in a drum kit.

Explanation of Crossovers and How They Work

Simply put, crossovers are parts in your car’s audio system that split the audio signal into separate bands of frequency. Each band is then directed to the speaker that can best handle it. The main job of a crossover is to ensure each speaker only deals with the specific frequencies it was designed to reproduce. This way, the sound quality of your system is greatly improved.

When used, crossovers allow music enthusiasts to enjoy a more balanced and accurate sound. How does this work? The crossover has built-in circuits that filter out unnecessary frequencies, directing them to the speakers best suited to manage them. This division of frequencies means each speaker can focus on its designated range. As a result, the clarity, sound imaging, and overall audio performance are noticeably improved.

Crossovers are parts of the car's audio system

The Importance of Crossovers in Car Audio

Crossovers are a crucial part of car audio systems, helping to overcome any restrictions due to the car’s interior or speaker positioning. Here’s why they are so important:

Frequency segregation: Crossovers make sure each speaker gets only the frequencies it can correctly handle. This stops any distortion and keeps the audio signal pure and clear.

Protecting the speakers: They work like a guard, blocking any unwanted frequencies. This critical function keeps your speakers safe from potential harm that could occur if they had to handle frequencies outside their designed range.

Boosting the soundstage: When used correctly, crossovers help create a richer, more life-like soundstage in your car. This means that each instrument and voice can be heard from its intended location, making your listening experience more enjoyable.

Balancing the sound: They help maintain a balanced sound by controlling the loudness and intensity of different frequency bands. This ensures that no frequency band overpowers or is drowned out, leading to a pleasing and natural sound.

Different Types of Crossovers

Crossovers are generally available in three main forms – passive, active, and digital.

  • Passive crossovers: These are the most common type, usually built directly into most speakers. They operate without an additional power source and function post-amplification in the audio system.
  • Active crossovers: These are a bit more complex and require a separate power source for operation. They split the signal before it’s boosted, giving you a greater handle on the sound but need additional equipment.
  • Digital crossovers: Operating in the digital domain, these offer a higher degree of control and flexibility over your sound system. However, they need a digital signal to function effectively.

Choosing the Right Crossover For Your Car Audio

The best crossover for your car audio largely depends on your specific needs, the complexity of your system, and your budget.

In detail, for a simple system, a passive crossover might be enough. However, if you want more control over your sound, so, an active or digital crossover would be a better choice. Remember, the quality of the crossover will significantly affect your audio system’s sound quality.

Car audio system

Setting the Crossover in Your Car Audio

You’re in luck if your car is equipped with a modern AV receiver that includes an auto EQ feature. Cars with this feature will automatically assign the right crossover frequency, so it’s usually best to keep these settings as they are, given they’re specifically adjusted for your car’s audio system.

For cars lacking a modern AV receiver, doing this task manually may require a bit of time and effort. So, it needs a lot of listening and fine-tuning to achieve the optimum sound.

Here are the steps you can follow to set a crossover frequency:

  • Step 1: Start by playing a song you’re familiar with, one that covers a good range of frequencies, including bass, mid-range, and high-range sound. Listen carefully and figure out which range sounds the best at the moment.
  • Step 2: Set the crossover point around 10 Hz lower than the lowest frequency your speakers can handle without a hitch. Note that the most commonly recommended frequency is 80 Hz.
  • Step 3: You continue to check for distortion. In detail, you play some more music and gradually increase the volume on your receiver. As soon as you hear the sound start to distort, reduce the volume until the sound is clear again. Take note of the volume level on your receiver at this point, as it represents your receiver’s volume threshold.

If the sound seems distorted or unbalanced, adjust the crossover points. If the bass sounds too loud or distorted, you might want to increase the frequency of the low-pass filter. Similarly, if the treble seems harsh, consider lowering the frequency of the high-pass filter.

  • Step 4: Now, we come up with adjusting the subwoofer amp. Lower your subwoofer amp’s gain to the smallest value possible (fully counterclockwise). Then, activate the low-pass filter and set it as high (turn it fully clockwise).

Once you’ve made these adjustments, it’s time to give your system another listen. Play some more audio and focus on how smoothly the sound switch from the speakers to the subwoofer. Ideally, the bass signal should blend perfectly with the rest – it should seem like the whole audio is playing in sync.

  • Step 5: About the bass, if you perceive a bass bump when adjusting the crossover frequency, you may need to fine-tune the volume control to match the output of your main speakers. To do this, push the volume of your receiver up to its highest level which doesn’t produce distortion. From this level, start to slowly turn up the gain on the subwoofer amp until the bass sounds in harmony with the rest of the audio spectrum.
Adjust the volume in the car audio system


Crossovers are vital to enhancing your car audio experience. Understanding their role, types, and correct setup can significantly influence the sound output of your audio system.

It may seem like a lot to take in, but with the right knowledge and approach, you can optimize your car’s audio system for the ultimate music experience.


  1. Is the sound quality enhanced by a crossover?

    Yes, of course. A crossover is a device that helps make the sound in your car better. It tells which sounds go to which speakers in your car. Now, if your crossover is designed well, it can really improve how the music sounds in your car. But if the crossover is not well designed, it doesn't matter how good your speakers are, the music won't sound as good.

  2. What would be the optimal crossover setting for car audio?

    Generally, for speakers that handle the middle range of sounds, setting a crossover frequency around 80 to 120 Hz is often recommended. For subwoofers, which deal with a lower range of sounds, a setting between 40 to 80 Hz is typically considered suitable. The best setting will depend on your personal choice and the specific acoustics of your car.

  3. Is a crossover necessary if my amplifier already has one?

    For simpler setups with just a single amplifier, you may not require an additional crossover. However, for more complex systems, an active crossover can be quite beneficial. For example, in cases where you have multiple amplifiers, a 3-way crossover, which is wired between your head unit and amplifiers, can make a significant difference.