Speaker Crossover Frequency Calculator
Calculate first-order crossover frequencies for high-pass (RC), low-pass (RL), and band-pass (LC) filter networks given speaker impedance and component values.
Results
What is it?
A crossover network splits an audio signal into frequency bands and directs each to the appropriate driver (woofer, tweeter, midrange). First-order crossovers use a single capacitor (for tweeter high-pass) or single inductor (for woofer low-pass). The cutoff frequency (-3dB point) is where the RC or RL time constant equals 1/2p.
How to use
Enter the speaker's nominal impedance and your chosen component values. The calculator gives the -3dB crossover frequency for both the high-pass and low-pass sections. To design for a specific frequency, rearrange: C = 1/(2p � f � R) and L = R/(2p � f). The LC resonance frequency indicates where an LC band-pass filter would peak.
Example scenario
Designing a 2-way with 8O woofer and tweeter, targeting 2,500 Hz crossover. For the tweeter high-pass: C = 1/(2p � 2500 � 8) = 7.96�F ? use 8.2�F standard value ? fc = 2,440 Hz. For the woofer low-pass: L = 8/(2p � 2500) = 0.509 mH ? use 0.5mH ? fc = 2,546 Hz.
Pro tip
First-order crossovers (-6dB/octave) have good phase characteristics but poor driver protection. Tweeters can be damaged by bass frequencies. For better driver protection and steeper rolloff, use second-order (L-C, -12dB/octave) or third-order (-18dB/octave) designs. High-order crossovers also allow acoustic summation adjustments to correct driver time alignment.