Crossover Calculator

The crossover frequency is the point at which an audio signal is divided between different speakers. Frequencies below the crossover point are sent to the woofer (low-pass path), while frequencies above it go to the tweeter (high-pass path). A common crossover frequency for 2-way speakers is between 2,000 Hz and 5,000 Hz.

The order refers to how steeply the filter rolls off unwanted frequencies. A 1st order filter rolls off at 6 dB/octave, 2nd order at 12 dB/octave, 3rd order at 18 dB/octave, and 4th order at 24 dB/octave. Higher-order crossovers require more components but do a better job of protecting tweeters from damaging low-frequency energy.

Butterworth filters provide a maximally flat frequency response in the passband. Linkwitz-Riley filters are designed so each filter is -6 dB at the crossover frequency, meaning the combined output sums flat — they are popular in professional audio. Bessel filters prioritize phase linearity and time-domain accuracy over amplitude flatness.

A Zobel circuit (also called an impedance stabilization network) is connected in parallel with a speaker to flatten its rising impedance at high frequencies. Without it, the actual crossover frequency can shift because speaker impedance is not constant across the frequency range. It consists of a resistor and capacitor calculated from the speaker's DC resistance and voice coil inductance.

Choose a crossover frequency that falls between the upper limit of your woofer's usable range and the lower limit of your tweeter's usable range. Tweeters typically can't handle frequencies below 1,500–2,000 Hz safely, and woofers start beaming (poor dispersion) above a few kHz. Check each driver's datasheet and aim for a frequency where both operate comfortably.

Use the nominal impedance rating printed on your speaker — most home audio drivers are 4, 6, or 8 ohms. For best accuracy you can measure the actual DC resistance with a multimeter and multiply by approximately 1.25, but the nominal rating printed on the datasheet works well for crossover design purposes.

This calculator computes a 2-way crossover (one crossover point splitting signal between a tweeter and woofer). For a 3-way design with a separate midrange driver, you would run the calculator twice: once for the woofer-to-midrange crossover and once for the midrange-to-tweeter crossover, then combine the resulting component networks.

Capacitor values are given in microfarads (µF) and inductor values in millihenries (mH). These are standard units used when purchasing audio-grade crossover components. When building your crossover, use non-polarized capacitors and air-core or iron-core inductors rated to handle your amplifier's current output.