Crossover Frequency Calculator

The geometric mean (the square root of the two values multiplied together) sits proportionally between the two limits on a logarithmic scale, which is how humans perceive pitch and how frequency response is normally graphed. A plain arithmetic average would skew the crossover point toward the higher of the two numbers when plotted on that log scale, placing it in the wrong perceptual location.

The slope, measured in decibels per octave, describes how sharply the crossover filter attenuates frequencies outside a driver's assigned range. A 12 dB/octave slope is gentler and preserves more phase coherence between drivers, while 24 dB/octave cuts more aggressively, better protecting a driver when its usable range doesn't overlap much with its neighbor's.

Not on this calculator's say-so alone. A dedicated midrange driver only helps if its own frequency response and dispersion pattern are suited to the range you're handing it — adding a third driver without matching its characteristics to the low-mid and mid-high split points this tool suggests can introduce more problems than it solves.

When two drivers are spaced apart by roughly a quarter wavelength or more at the crossover frequency, their overlapping output can interfere destructively at certain listening angles, a problem called comb filtering. A shorter wavelength at crossover (a higher crossover frequency) gives you less physical room between drivers before that interference becomes audible.

Treat it as a starting estimate rather than a final design value. Real driver frequency response, cabinet diffraction, and baffle step all shift the ideal crossover point away from this simplified geometric-mean estimate, so passive crossover designers typically verify and refine the point with actual impedance and frequency-response measurements before finalizing component values.