RACK/FILTERS & ENCLOSURES

H(f)

Crossover filters

Shape the handoff. See exactly what your filter does.

Inputs

YOUR SYSTEM

Frequency

2020000

Filter order

Filter type

Result

METER

Asymptotic roll-off

12.0dB/oct

2-order low-pass Butterworth response

Response at cutoff

-3.01dB

Slope per decade

40dB/dec

Cutoff frequency

1,000Hz

Butterworth magnitude response: Ideal Butterworth filter

How it works

The slope is only part of the story.

A Butterworth filter has a flat passband and is down about 3 dB at its cutoff. Increasing the order makes the transition steeper and adds more phase shift.

The formula

L(f) = -10 \log_{10}\left(1 + \left(\frac{f}{f_c}\right)^{2n}\right) \quad \text{(low-pass)}

$f_c$ — cutoff frequency in $\text{Hz}$
$n$ — filter order
High-pass: replace $f / f_c$ with $f_c / f$

Worth knowing

Two Butterworth sections do not automatically make a flat-summing crossover. Linkwitz-Riley filters have different crossover behavior and are not modeled here.

Assumptions

An ideal electrical magnitude response, not the acoustic sum of real drivers. Driver response, phase, polarity, latency and other filter families are not included.

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Phase shift EQ bandwidth Subwoofer spacing