What impedance value should I enter?

Use the nominal impedance printed on the driver — usually 4, 6, or 8 ohms. For best accuracy, use the impedance at the crossover frequency from the driver's impedance curve, but nominal impedance gives a good starting point.

What is the difference between 1st, 2nd, and 3rd order crossovers?

The order sets the rolloff slope: 1st order = 6 dB/octave, 2nd order = 12 dB/octave, 3rd order = 18 dB/octave. Higher-order crossovers have steeper slopes and better driver protection but use more components and introduce more phase shift.

What filter alignment does this calculator use?

The 2nd and 3rd order designs use Butterworth (maximally flat) alignment. For 2nd order Linkwitz-Riley, multiply the capacitor value by 2 and the inductor value by 1 (the frequency is set to the -6 dB point instead of -3 dB).

Why do the low-pass and high-pass sections use different formulas?

The low-pass section uses an inductor in series with the woofer; the high-pass section uses a capacitor in series with the tweeter. Each topology has its own transfer function, so the component values differ even at the same crossover frequency.

Can I use this for active crossovers?

No. Active crossovers use op-amp circuits whose values depend on resistors, not speaker impedance. This calculator is for passive L-C crossover networks only.

How accurate are these values?

The formulas give ideal theoretical values. Real-world performance depends on driver impedance variation, component tolerances, and enclosure loading. Always verify with measurement software (e.g. REW) after building.

Crossover Frequency Calculator

Name: Crossover Frequency Calculator
Availability: InStock
Author: Nham Vu

Enter speaker impedance and target crossover frequency to compute inductor and capacitor values for 1st, 2nd, or 3rd order passive crossover networks.

Crossover Parameters

Speaker Impedance (ohms)

Nominal impedance of the driver (e.g. 4, 6, or 8 ohms)

Crossover Frequency (Hz)

Target -3 dB crossover point in Hz

Crossover Order

Enter parameters and click Calculate to see component values.

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Summary

Enter speaker impedance and target crossover frequency to compute inductor and capacitor values for 1st, 2nd, or 3rd order passive crossover networks.

How it works

Enter the nominal impedance of your speaker driver (typically 4, 6, or 8 ohms).
Enter the target crossover frequency in Hz (e.g. 3000 Hz for a tweeter crossover).
Select the crossover order: 1st (6 dB/oct), 2nd Butterworth (12 dB/oct), or 3rd Butterworth (18 dB/oct).
The calculator applies standard Butterworth filter formulas scaled by impedance and frequency.
Read off the low-pass inductor and high-pass capacitor values for each section.
Use the computed L and C values to source or wind your crossover components.

Use cases

Designing a DIY 2-way or 3-way loudspeaker crossover.
Verifying existing crossover component values against spec.
Selecting between crossover orders for a target rolloff slope.
Teaching passive filter theory and component scaling.
Prototyping crossover networks before ordering parts.
Calculating component values when upgrading crossover capacitors or inductors.

Frequently Asked Questions

Last updated: 2026-06-10 · Reviewed by Nham Vu