Passive 3-Way Crossover Calculator (1st Order)
Enter your two crossover frequencies and driver impedances. This calculator returns ideal starting values for a simple 6 dB/octave passive network.
What this 3 way crossover calculator does
A 3-way speaker splits sound into three bands: bass (woofer), midrange (mid), and treble (tweeter). To do that, you pick two crossover points:
- f1 (Low-Mid): where woofer hands off to midrange
- f2 (Mid-High): where midrange hands off to tweeter
This page calculates first-order passive component values. In practical terms, that means a simple network with gentle slopes and fewer parts, useful for quick prototypes and educational design work.
Formulas used (1st-order, ideal load)
Capacitor (high-pass branch)
Where C is in farads, R is driver impedance in ohms, and f is crossover frequency in Hz.
Inductor (low-pass branch)
Where L is in henries.
How they map to each driver
- Woofer (low-pass): one series inductor at f1
- Midrange (band-pass): one series capacitor at f1 and one series inductor at f2
- Tweeter (high-pass): one series capacitor at f2
Example
If you choose f1 = 500 Hz and f2 = 3500 Hz with all drivers at 8 Ω, you’ll get a workable baseline set of parts. From there, you can tune by ear and measurement software (REW, ARTA, SoundEasy, etc.).
Important real-world notes
1) Driver impedance is not flat
A driver labeled “8 Ω” may vary dramatically with frequency. So these results are theoretical starting points, not final production values.
2) Acoustic crossover is different from electrical crossover
Cone breakup, cabinet diffraction, baffle step, and driver roll-off all change final response. Electrical values alone do not guarantee flat summed output.
3) You may need attenuation (L-pad)
Tweeters are often more efficient than woofers. If highs sound too loud, add an L-pad or active DSP level trim.
4) Polarity and phase matter
If you hear a dip near crossover, try polarity inversion on one driver section and verify with measurements.
Choosing good crossover frequencies
- Keep crossover points away from major resonance peaks.
- Use driver datasheets as a safe starting guide.
- Avoid crossing a tweeter too low unless power handling supports it.
- For midrange, choose a passband where distortion stays low.
FAQ
Can I use this for 4 Ω drivers?
Yes. Enter each driver’s nominal impedance directly.
Is this calculator for active or passive crossovers?
These formulas are for passive component values (capacitors/inductors).
Will this produce a perfect speaker?
No single calculator can do that alone. Use this as a launch point, then measure, simulate, and refine.