How to Set Crossover Frequency for Car Audio System

Last Updated on January 17, 2023

Most drivers are challenged by setting a crossover frequency, especially if it is a new car audio system. To solve that puzzle, you have first to understand what crossovers are and how they function. The crossover is responsible for filtering unwanted sound waves so that they don’t transfer frequencies. With a crossover, you will send different speakers with the ranges they are most efficient with. 

Setting your crossover frequency for your car audio system will require you to use your ears to get the frequency of your liking. You also have to set the HPF and LPF for your main speakers and tweeters, respectively. Set the switch to individual positions, starting with HP, then moving to the LP. The frequencies should range from 60-80 Hz for both.  

Every speaker will get a frequency at which it will reproduce the best sound. That will overall improve the whole system’s sound quality and volume. How the filters are set depends on your sound system. However, three general settings determine the outcome of the crossover. They include:

• Frequency: This is measured in Hertz (Hz); it is the level at which the filter starts functioning.
• Bandpass, high-pass, low-pass: This will determine whether some ranges will pass the filter or block.
• Q-factor or slope: determines the audio system volume rate to diminish when the frequency extends past the crossover point. It is measured using (dB) decibels per octave. The most common slope range is between 12dB and 24dB per octave.

A 12 dB slope is considered a more gradual cutoff. It is used in coupes and sedans with subwoofers in their trunks. The car’s rear seat acts as a filter and can minimize upper bass range amplitude to counter that the 12dB slope will increase the bleed-through frequencies.

For a 24 dB slope, it is more of an abrupt cutoff. It is best used in open vehicles like hatchbacks, wagons, and SUVs. For open cars, it is hard for the bass to filter through the seat material. The 24dB slope is more abrupt, and users can use a slightly lower crossover between midrange and tweeter.

General rules to follow to guide you on how to set the crossover frequency for the audio system of the car: 

• For a subwoofer, it can only handle a frequency as high as the filter settings can go.
• For a speaker, the lowest frequency it can control is the lowest setting on its crossover.

Now that you’re familiar with how to set crossover frequency for a car audio system, let’s jump to the topic of the day.  

How to Configure Crossover Frequency for Car Audio Systems 

Today, most car systems come with built-in low and high-pass crossovers you can use to improve your car’s audio system sound to your liking. And you know what? Setting up your crossover frequencies is simpler if you have the know-how. 

What’s more, when setting your car audio system crossover frequency, you don’t need the exact frequency; an approximation will be just right. 

How to Set High-Pass Filters (Main Speakers)

The high-pass crossover feature helps reduce distortion, get you more volume, and prevent bottoming out. It’s set to control your main speakers, the small speakers. How do you set its frequency?

• Turn all the EQ functions and the bass boost off before making any adjustments. 
• Set your crossover switch to the High-Pass (HP) position – if provided. 
• Using a small screwdriver, turn the frequency setting to its lowest setting. 
• Tune the frequency up slowly to your liking. Mostly it’s around 60-70 Hz – at times, you might want to keep it higher than bass to get a clear sound. 

How to Set Low-Pass Filters (Sub-Woofers)

The low-pass crossover filters can help you send pure bass to your car audio system subwoofers. It keeps the vocals and the instruments out of your subwoofer channels while eliminating distortion. How do you set the frequency? 

• Turn all the EQ functions and the bass boost off before making any adjustments. 
• Set your crossover switch to the Low-Pass (HP) position – if provided. 
• Using a small screwdriver, turn the frequency setting to its lowest setting. 
• Tune the frequency up slowly to your liking. Mostly it’s around 70-80 Hz. It would be best if you got enough pure bass at this frequency.

Having set the low and high-pass frequencies, you still need to master how to set subwoofer crossover frequency options. Continue reading this document to outline the settings you need to be familiar with and the recommended crossover frequencies. 

Front components (subwoofer (s) and passive crossovers)

You can use a high pass filter in this kind of audio system. The filter will be able to split the frequency between tweeters and midrange drivers efficiently. 

For the midrange drivers, low bass will be blocked out as they will not effectively play them. A low pass filter will be used for a subwoofer so that high ranges are not sent to subwoofers. 

If the slope options are adjustable, you can switch them to achieve the quality of sound you like. 12Db is the most common slope option used by many car audio systems in green and 24dB for orange.

Front Components (passive), Subwoofer (s), and Rear Coaxial Speakers

Since the coaxial speakers have been added, the system slightly changes from the one above. If the added speaker uses a crossover network, the settings will remain how you set them using the component speakers. Both coaxial speakers and component speakers should use a high pass filter with a 12 or 24Db per octave slope. With subwoofers, you will use a low pass filter with the type of slope that you prefer. 

Almost all coaxial speakers have basic filters instead of passive crossovers. The filter blocks the tweeter from getting low sound waves. The midrange will then roll off the frequency depending on the tweeter, but you should use a high pass filter to block the lower groups. 

The above two stereo systems that have been discussed are the common types of configurations in cars. It is assumed that the speakers have a diameter of not less than 5.25 inches for the recommendations given. 

If it is a small speaker, the high pass filter frequency should be set higher than 80Hz. Start from 300Hz, then go down while listening to the sound quality until you are satisfied. If the midrange seems stressed, tune up the filter or go down until the stress is no longer. 

The below systems are called active systems and come with a more advanced configuration. When it comes to them, you have to use electronic crossovers. Below are the systems and their recommended filter settings.

Subwoofer (s) and Active Front 2-Way Components 

Electronic crossover is used here to 500Hz high pass the tweeter, low pass the subwoofers (80Hz), and bandpass the midrange at 80 Hz. The slope can be set as either 12dB or 24 dB

Subwoofer (s) and Active Front 3-Way Components 

The above system uses a three-way active front stage together with a pair of tweeters. That is because they have big woofers and small midrange speakers. The front stage is even more efficient when reproducing sound than when using a two-way component set. Below are some recommended settings.

HPF and LPF Settings on Head Unit: Woofers to bandpass are 80Hz HPF and 500 Hz LPF, tweeters are equal to 5000 Hz HPF while midrange to bandpass is equal to 500Hz HPF and 5000 Hz LPF. When it comes to subwoofers, it is equal to 80 Hz LPF. With the slope options, you can set them at 12 dB or 24 dB

To understand how to set car audio systems’ crossover frequency, you must first know how it is configured. You have to be familiar with the system’s rear and front speakers, as it will determine the type of frequency and filter you will use. 

The recommendations given in this post may differ from others, so you have to learn to fine-tune. The given recommendations can be used as guidelines, and your fine tuning will determine the final set. It will also depend on the quality of sound that you like the most.

Who Needs Installing a Crossover for their Car Audio System?

A crossover for your car audio system can bring the best sound quality you’ve been yearning for. Even though modern coaxial speakers and stereos have inbuilt crossovers, adding a standalone system can enhance your crossover frequency output. 

But if your car uses coaxial speakers only, there is no need for a crossover. The use of full-range coaxial speakers with inbuilt crossovers can filter the frequencies as most people would like. 

However, consider installing a crossover system if you’re planning or if you already have a subwoofer, amplifier, and other component speakers. 

Remember, if you need individual amplifiers to power specific speakers in your car, you might need to install more than one crossover. 

Suppose you have one amp powering subwoofers and another powering the tweeters and component speakers; you need two crossovers for each amp. 

If you’re looking for a more straightforward setup, investing in a car amp that comes with an inbuilt crossover will be the best idea. 

The low-pass filters with an inbuilt crossover will drive the subwoofers, while the high-pass filters drive the tweeters.

That way, there is no need to install a standalone crossover, thus keeping your system more straightforward and easy to install. 

Do You Need A Professional?

It might sound mildly complex, but a crossover frequency setup for a car audio system isn’t that complicated. If you have the proper knowledge and skill in handling audio systems, you can control the setup. 

The passive crossovers are the simplest as they require you to wire the crossover system between the speakers and the amplifier. 

However, active crossovers will need some additional steps and some level of expertise. They require separate power, which means you must run power and ground wires to each crossover.

If you want to DIY the setup, it’d be best to ground the crossover at the same spot where you grounded the amplifier. 

If you have little to no practical experience with car audio system installations, the best idea is to hire a professional. 

An expert can install the systems and set up the crossover frequency for your car audio system as you like it, saving you time and the hassle involved. 

Frequently Asked Questions (FAQ)

Does a Crossover improve sound quality?

Yes, of course. When you set the crossover frequency for your car audio system, you should get clear sound and high-quality bass with zero distortion. Every frequency has its own setting, meaning you can control the primary speakers’ frequency and subwoofer bass separately for improved sound quality. 

What is a good Crossover Frequency for Car Audio?

The best crossover frequency for car audio is between 60 Hz and 80 Hz, depending on the two HPF and LPF settings. The High-Pass Filters frequency should be between 60 and 70 Hz, while the Low-Pass Filters frequency should be between 70 and 80 Hz. 

Crossover Frequency Setting: Improving Car Audio System Sound Quality

And now you know how to set crossover frequency for a car audio system. As previously stated, the entire setup is simple for a handy DIYer with some practical experience in setting crossover frequency for car audio systems. Everything you need to set up the crossover frequencies ultimately is in this guide. Remember, this guide provides steps to setting up generalized crossover frequencies; you can make a few tweaks to match your personal preferences. Use the ears to configure them to your liking.