Passive Crossover Network Designer
Calculate 1st, 2nd, 3rd, and 4th-order Butterworth & Linkwitz-Riley capacitor and inductor values with live schematic & Bode plot.
How It Works & Acoustic Engineering Principles
Physical Mechanism & Theory
A passive loudspeaker crossover divides the full-range amplified signal into dedicated frequency bands tailored to each driver’s physical piston range. Capacitors block low frequencies and pass high frequencies (reactance X_C = 1 / 2πfC), while inductors pass low frequencies and choke highs (reactance X_L = 2πfL).
While a 1st-order Butterworth filter rolls off gently at 6 dB/octave with perfect transient summation, it forces tweeters to handle dangerous excursion below resonance. Even-order Linkwitz-Riley alignments (2nd-order 12 dB/oct and 4th-order 24 dB/oct) cascade two Butterworth filters in series so both drivers are at -6 dB (half voltage) and 0° relative phase at f_c, producing a ruler-flat +0 dB acoustic sum and symmetrical vertical polar lobing.
Studio Bench Rules of Thumb
- 01.Cross At Least 1 Octave Above Tweeter Fs: Never cross a dome tweeter near its resonant frequency f_s with a shallow slope; aim for f_c ≥ 2 × f_s using at least 12 dB/oct or 24 dB/oct slopes.
- 02.Use Film Capacitors in the Tweeter Signal Path: Choose polypropylene film capacitors (MKP) rather than electrolytic caps for series high-pass filtering to minimize dielectric distortion and ESR.
- 03.Orient Inductors at 90° Angles: Mount adjacent crossover coils perpendicular to one another on the board to prevent magnetic crosstalk.