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Dehum

Cut mains hum and its harmonic series.

Visual walkthrough3 configuration controlsSynced audio walkthrough
See how it works ↓

Amount changes notch depth, not a broadband noise level. Zero Amount is unity. Harmonic centers must remain below the graph-rate eligibility boundary.

01 / Understand

The idea, before the settings.

A selected 50 or 60 Hz mains fundamental creates a series of up to eight narrow finite-depth cuts at its harmonics. Amount controls notch depth.

Humming sourceDehumOutput

Use it in AudioRouter

  1. Identify whether the unwanted fundamental is near 50 or 60 Hz.
  2. Set that Frequency, start with Amount 50% and a small harmonic count.
  3. Add harmonics only where higher buzz remains, then compare lower voice notes or bass for damage.

What success looks like

Narrow notches reduce the fundamental and selected multiples while leaving most surrounding sound alone.

If it does not work

If the buzz remains, verify its frequency. Broadband hiss needs a different treatment; more notches can remove wanted low notes.

Select the node to open Properties. Click its name to rename it. While playing, supported parameter-only edits save after a short pause. For structural edits, use Save when the canvas marks a change. Enabled and Bypass are distinct live controls; see the in-app help for their behavior.

02 / Explore

Make the behavior visible.

The input contains a known 60 Hz hum with eight harmonics. Compare 50 versus 60 Hz and change the harmonic count to hear why matching matters.

The example repeats until you press Stop, and control changes are heard immediately. The picture shows the tool's shape rather than time; follow the timing in Follow the sound below. This is not a DSP measurement or control for your running AudioRouter session.

03 / Configure

Every control, with a reason.

01

Mains frequency

frequencyHz

Fundamental of the unwanted hum series.

Range / choices45 Hz → 65 HzDefault60 Hz

↓ Lower / alternativeMoves the series lower.

↑ Higher / alternativeMoves every notch in the harmonic series higher.

Try thisUse 60 Hz for measured 60 Hz hum or 50 Hz for 50 Hz hum.

Keep in mind Match the actual noise; location alone is not a measurement.

02

Amount

amountPercent

Depth of each hum notch.

Range / choices0 % → 100 %Default50 %

↓ Lower / alternativeApproaches exact unity at 0%.

↑ Higher / alternativeMakes the selected narrow cuts deeper.

Try this50% maps to −18 dB at each notch center.

Keep in mind 100% maps to −36 dB per notch; it is not infinite removal.

03

Harmonics

harmonics

Number of selected multiples including the fundamental.

Range / choices1 → 8Default4

↓ Lower / alternativeLimits treatment to fewer hum components.

↑ Higher / alternativeCuts additional higher multiples.

Try thisAt 60 Hz and four harmonics: 60, 120, 180 and 240 Hz.

Keep in mind Only eligible harmonics below the graph-rate boundary are used.

04 / Put it to work

Start with a useful example.

Example 1

Treat a 60 Hz buzz

  1. Select 60 Hz, Amount 50% and four harmonics.
  2. Compare the hum between wanted sounds.
  3. Increase Amount or harmonics only where the unwanted series remains.
Example 2

Treat 50 Hz mains hum

  1. Select 50 Hz.
  2. Begin with two harmonics and listen.
  3. Increase the count if higher multiples remain audible.

These are starting points. Compare at a comfortable monitoring level and adjust for your own source.

05 / Get unstuck

Small details that matter.

  • The wrong fundamental misses the actual hum.
  • More harmonics affect more narrow regions of wanted sound.
  • Dehum is not a general fan-noise remover.