Audio Crossover Frequency Calculator
Calculate crossover frequencies for passive and active speaker systems.
Find capacitor and inductor values for 1st, 2nd, and 3rd order crossover networks.
A crossover is a filter network that divides an audio signal into separate frequency bands for different speakers. Without a crossover, a tweeter receiving bass frequencies would be damaged, and a woofer receiving high frequencies would produce distortion.
Why Crossovers Are Necessary
Different speaker drivers are optimized for different frequency ranges:
- Subwoofer: 20–80 Hz (very low bass)
- Woofer: 40–500 Hz (bass and upper bass)
- Midrange: 300 Hz – 5 kHz
- Tweeter: 2 kHz – 20 kHz
A crossover filters each driver so it receives only the frequencies it can handle efficiently.
Crossover Orders
1st Order (6 dB/octave): Single capacitor for high-pass, single inductor for low-pass. Simple, phase coherent. Used in simple 2-way systems.
2nd Order (12 dB/octave): More aggressive filtering with better driver protection. Most common in home audio.
3rd Order (18 dB/octave): Better isolation, used in professional and high-performance systems.
4th Order Linkwitz-Riley (24 dB/octave): Flat summed response, excellent isolation. Common in studio monitors.
The Formulas
For a 1st order passive crossover at frequency f (Hz) with impedance Z (ohms):
Capacitor (high-pass): C = 1 / (2π × f × Z)
Inductor (low-pass): L = Z / (2π × f)
For 2nd order Butterworth: C = √2 / (4π × f × Z) L = Z × √2 / (4π × f)
Typical Crossover Points
- Subwoofer to woofer: 80–120 Hz
- Woofer to midrange: 400–800 Hz
- Midrange to tweeter: 2,000–5,000 Hz
- Woofer to tweeter (2-way): 2,000–4,000 Hz
Impedance Note
Nominal impedance for home speakers is typically 4, 6, or 8 ohms. Car audio speakers are often 4 ohms. Use the manufacturer’s specified impedance for accurate component calculations.