Figure 1: A 2-way crossover splits the audio signal at the crossover frequency. The low-pass section feeds the woofer; the high-pass section feeds the tweeter. Component values depend on fc and speaker impedance.
Table of Contents
What Is a Speaker Crossover?
A speaker crossover divides an audio signal into separate frequency bands for different drivers. The woofer handles bass, the midrange handles vocals, and the tweeter handles treble. Without a crossover, each driver would attempt to reproduce frequencies outside its optimal range, causing distortion and reduced power handling. The Filter Cutoff Frequency Calculator covers the fundamental frequency calculation that underpins crossover design.
How It Works
A crossover network uses LC filters (inductors and capacitors) to split the signal. First-order crossovers use one component per driver (−6 dB/octave). Second-order Butterworth use two (−12 dB/octave). Fourth-order Linkwitz-Riley (−24 dB/octave) is the professional standard for flat acoustic summing. The RC Filter Calculator shows the individual filter stages.
Worked Example — 2-Way Bookshelf Speaker
1st order: C = 1/(2π×3000×8) = 6.63 µF, L = 8/(2π×3000) = 0.424 mH
The RL Filter Calculator can verify the individual filter sections.
Worked Example — 3-Way Floor Standing Speaker
The woofer gets a 500 Hz low pass, the midrange gets 500-5000 Hz bandpass, and the tweeter gets a 5 kHz high pass.
The LC Filter Calculator handles the bandpass section calculation.
Crossover Order and Slope
First-order (−6 dB/oct) has the best phase response and simplest construction but poor driver isolation. Second-order Butterworth (−12 dB/oct) is a good compromise. Linkwitz-Riley (−24 dB/oct) provides flat acoustic power summing and excellent driver isolation — the industry standard for professional audio. The Low Pass Filter Calculator designs the individual LP and HP stages.
Impedance Matching
Speaker impedance varies with frequency — it is not constant at the rated value. This affects crossover accuracy. Zobel networks (a series RC across the driver) can flatten impedance. L-pads attenuate the tweeter without changing the crossover frequency. The High Pass Filter Calculator covers complementary filter designs.
Impedance Calculator: The Impedance Calculator helps verify speaker impedance at the crossover frequency.
Frequently Asked Questions
How many ways should my crossover be?
Can I use active crossovers instead?
What about time alignment?
What capacitor types should I use?
Related Filter Calculators
Browse all Electronics Calculators →