Crossover Calculator

About the Crossover Calculator

A passive crossover splits audio into frequency bands so each driver handles the range it was built for. In a 2-way or 3-way speaker, that usually means keeping low frequencies away from the tweeter and steering upper mids and highs away from the woofer.

This calculator works out the capacitor and inductor values for common passive crossover topologies, including Butterworth and Linkwitz-Riley designs from 1st through 4th order. Enter the target crossover frequency, speaker impedance, and filter order to see the component values for the high-pass and low-pass sections.

It is useful when you are designing a custom speaker, checking a car audio crossover, or comparing how steeper filter orders affect phase and driver protection. The result changes with impedance, frequency, and order, so the calculator makes those tradeoffs visible without manual filter math.

When This Page Helps

Use this calculator when you need component values for a speaker network and want to compare filter orders before buying parts. It is especially helpful for custom builds, speaker upgrades, and crossover experiments where impedance and cutoff frequency both matter.

How to Use the Inputs

1. Select a preset configuration or enter custom values below.
2. Enter the desired crossover frequency in Hz (where the woofer and tweeter transition).
3. Input the nominal impedance of your speakers in ohms (typically 4Ω or 8Ω).
4. Choose the filter order—higher orders give steeper rolloff but require more components.
5. Enter driver sizes for reference and any tweeter level adjustment needed.
6. Review the component summary table for all required capacitors and inductors.
7. Use the order comparison table to understand the trade-offs of each filter topology.

Example Calculation

Tips & Best Practices

• Use air-core inductors for tweeters to avoid saturation distortion.
• Measure actual driver impedance at the crossover frequency—it may differ from nominal.
• Add a Zobel network to flatten impedance rise at higher frequencies.
• Use film capacitors (not electrolytic) for high-pass sections for best sound quality.
• Higher-order crossovers provide more driver protection but add insertion loss.
• Test your crossover on a breadboard before permanent installation.

Crossover Design Notes

Match the calculated parts to the exact driver impedance you plan to use, then compare the resulting rolloff and phase behavior against the rest of the system.

Tuning Mistakes to Avoid

A crossover often looks correct on paper but fails in practice when the driver impedance is only approximate, the capacitor value is rounded too aggressively, or the chosen order creates an awkward acoustic overlap.

Frequently Asked Questions

• What crossover frequency should I use?

  The crossover frequency depends on your drivers. A typical 2-way bookshelf uses 2000–3000 Hz. For subwoofer-to-main crossovers, 60–120 Hz is common. Choose a frequency where both drivers can perform well.

• What is the difference between Butterworth and Linkwitz-Riley?

  Butterworth filters have a -3 dB point at the crossover frequency, while Linkwitz-Riley (4th order) has a -6 dB point, resulting in flat combined response. LR crossovers have better lobing behavior.

• Does speaker impedance matter for crossover design?

  Yes, the impedance directly affects component values. Using the wrong impedance will shift the crossover point. Use the nominal impedance (4Ω or 8Ω) of your driver.

• Can I use standard capacitor values?

  Yes, you can combine standard capacitor values in parallel to reach the calculated value. For example, get 5.6 µF by combining a 4.7 µF and 1.0 µF cap in parallel.

• What order crossover should I choose?

  1st order is simplest with best phase response but poor driver protection. 2nd order is the most popular. 4th order Linkwitz-Riley offers steep rolloff and flat summed power response.

• Do I need an inductor for a 1st order crossover?

  Yes, a 1st order low-pass uses a single inductor in series, while the high-pass uses a single capacitor in series. It is the simplest crossover topology.