[GUIDE] dB crossovers, values, and meaning for car audio

What are car audio crossovers? For car audio enthusiasts, understanding dB crossover values are important for getting the most out of your sound system. In this blog post, we’ll explore dB crossovers & values and what they mean for your car audio installation and overall experience. This is a brief guide, not a how-to, guiding you through this X-over phenomenon.

I will touch-based this on the passive crossover networks since most manufacturers in car audio are still using passive crossovers in 2-way and 3-way setups and suggested x over.

For the pro audio guys, there are more than just “bass blockers” and/or inline sleeve-style crossovers, as you see in most install -6 to -12 dB in their pro audio setup.

DSP tuning stuff will NOT be mentioned in this post. We won’t be looking at active crossovers, electronic crossovers, or other sound processing features; this post is about understanding, range, and hardware for sound frequency points.

What is a dB crossover value, and why is it important for car audio systems?

  • Crossovers play an important role in your car stereo, as they are responsible for the frequency separation of the components, such as speakers and mids, as well as tweeters. The crossover value is a measure of specific frequencies designed to produce steady audio output – too low or too high values may result in distortion or blown speakers. The crossover value will also determine which frequency ranges are sent to different outputs. Your Car speakers can sound amazing in the whole audio spectrum as long as you obey the crossover frequency boundary of the midrange drivers, tweeter drivers, and woofer drivers. Crossover filters are suggestions but should be, in my opinion, taken as law.

Passive Component speakers crossover range suggestions:

  • 2-way and 3-way passive component crossover for most speaker setups to revolve closely around the following numbers, hardware is resistors and either iron core or air core. Most great passive component crossover systems use air core, as they, in my opinion, do the best filtering for unwanted frequencies. The downside is they are bigger than the smaller iron core.
  • Crossover values below 20-250Hz will generally be directed to subwoofers or mid-bass frequencies from the 200-500Hz range. Users today loved subwoofer bass to be tuned to 31Hz and below on the subwoofer end; between 400Hz thru 4-5kHz will often be for mid-range frequencies, and from that set point, 4-5kHz range to 20kHz are typically used for tweeters.  Below is a diagram my mentor, Craig Smith, sent to me. We will cover hardware within the 2-way and 3-way crossovers later this year. All crossover frequencies are within the ranges even for passive crossovers and systems with multiple subwoofer amp (s).
  • Some of the passive crossovers have an easily selectable crossover slope; even some of the higher-end car stereo head units have crossover frequency responses within the volume controls. Use them and obey the gain and volume control when you set the crossover. Overlapping sound waves for the subwoofer’s frequency range and the rest of the speakers in the system is recommended.

Passive crossovers 2way 3way diagram for car audio

Again this is just an idea; installing the application does vary. It shows you where exactly each frequency range should more or less be for both low-pass and high-pass filters.

When tuning your 4-channel amplifier, you must stay within these ranges too, or you will have your speaker,  crossover, and amplifier fighting each other in some way and sounding horrible. Amplifiers with bandpassable crossover frequency tuning are, in my opinion, better control; amplifiers gain and amplifier processes signal.  The auto eq programs are usually only found in DSP. I get that question a lot, so i figured to throw it in here.

How to choose the right crossover values for your PRO audio system?

Having the right values is essential for an optimal car audio system. Crossovers help divide the sound frequencies and manage them according to the user’s preferences and speakers’ capabilities. Midrange speakers and crossover frequency within the component speaker system all play important roles in getting the proper crossover frequency for the perfect tune. Midrange bass capability is also a factor if your midrange speakers can produce a lower-range response. Dynamic range, Bass bump from midrange speakers bring out some amazing sound if your midrange driver can mechanically do so.

Regarding DB crossover values, most people opt for -6 dB or -12 dB, and even more, as seen below, for their car audio systems, as these are ideal for personal listening environments; with pro audio, you like loud and clear (hopefully). You need to see the speaker’s data to pick the ideal crossover point; some manufacturers supply this frequency you should crossover, and some do not, so best of luck. Again crossover points are decided based on the mechanical movement in electrical efficiency. Setting up your dB crossover values in your car audio system knowing the hardware values. The in-line crossover system and the speaker’s frequency range are all balance.

Setting up crossovers in your car audio system is an important part of a high-quality listening experience that is now known; crossovers are filters that divide high and low frequencies, allowing different speaker systems to be used for different types of sound. Set them close to the manufacturer’s recommendation.

By setting a high pass filter on your speakers, high-frequency sounds can be sent to the high-frequency speaker system, whereas a low pass filter will send lower frequencies to the subwoofer system. Installing the crossover with the correct hardware specs will enhance the sound quality in any vehicle and ensure that each speaker system handles its task properly. With this simple step of installing crossovers, you can ensure a high-quality audio experience while using your car’s audio system.

I’ve provided a chart of all the points and values below:

pro audio crossovers


We sell pro audio -12 db crossover,  in both 8 ohms and 4 ohms.


Conclusion with crossovers

Find out everything about the speakers you have, and ensure you know where exactly the best frequency point for the crossover is; remember to refer back to this guide if you forget anything mentioned in this post. It’s all about the system’s tonal response to set the crossover frequency response correctly and then dial it into your listen-to preference. Electronic crossovers are highly recommended for those big powered systems, especially the ones with a bunch of subwoofers; the subwoofer’s frequency response must be dialed into the rest of the system.

Best of luck tuning; I hope this helped.

About The Author aye_jake

CMO & PRODUCT DEV @ Down4sound Shop

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