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Spectral Gate

Gate individual frequency regions against a learned noise profile.

Visual walkthrough3 configuration controlsSynced audio walkthrough
See how it works ↓

Threshold above noise is a relative margin, not an absolute dBFS threshold. Reduction sets how far blocked regions are attenuated. Learn while only the unwanted background is present.

01 / Understand

The idea, before the settings.

Spectral Gate learns a noise profile, then compares each frequency region with a threshold above that profile. Reduction sets how deeply bins below the threshold are attenuated.

Noisy sourceSpectral GateOutput

Use it in AudioRouter

  1. Learn a noise-only interval, then keep the profile before evaluating speech.
  2. Start with Threshold 3 dB above the learned noise and Reduction 40 dB.
  3. Lower Threshold or Reduction if quiet syllables develop holes; relearn when the noise changes.

What success looks like

Frequency regions close to the learned background are attenuated; this differs from closing the entire signal with Gate.

If it does not work

A profile learned during speech can remove wanted frequencies. Correct the profile before applying stronger settings.

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.

A prepared noise layer makes threshold and blocked-region reduction audible. This deliberately simplified separation model does not simulate FFT bins or production artifacts.

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

Threshold above noise

thresholdDb

Required margin above the learned noise in each frequency region.

Range / choices-20 dB → 20 dBDefault3 dB

↓ Lower / alternativeLets more frequency regions pass.

↑ Higher / alternativeBlocks more regions.

Try thisTry 3 dB, then lower toward 0 dB if the voice thins.

Keep in mind This is relative dB above the profile, not dBFS.

02

Reduction

reductionDb

Attenuation of frequency regions the spectral gate blocks.

Range / choices0 dB → 80 dBDefault40 dB

↓ Lower / alternativeKeeps more sound in blocked regions.

↑ Higher / alternativeMakes blocked regions quieter.

Try this40 dB is the default; try less if spectral holes are audible.

Keep in mind Threshold decides what is blocked; Reduction decides how deeply.

03

Learn noise

learning

Runtime learning controlled by Learn and Keep profile actions.

Range / choicesOn / offDefaultfalse

↓ Lower / alternativeStop and keep the measured profile before evaluating speech.

↑ Higher / alternativeStart learning only while the unwanted background is present.

Try thisStay quiet while the fan runs, then keep its profile.

Keep in mind Requires a running enabled non-bypassed tool; the profile is stored by the editor rather than typed as raw hex.

Beyond the controls

Actions & transport

Learn noise

Start while the route is running, the tool is enabled and not bypassed, and only unwanted background is present.

Stop learning and keep profile

Stores the live 64-band profile and leaves learning mode. The editor writes the bounded profile; users do not type its 128-character hexadecimal representation.

04 / Put it to work

Start with a useful example.

Example 1

Create a noise boundary

  1. Start the route and click Learn noise while staying quiet.
  2. Keep the learned profile.
  3. Begin at Threshold above noise 3 dB and Reduction 40 dB, then evaluate quiet speech.
Example 2

Recover a thin voice

  1. Lower Threshold above noise toward 0 dB.
  2. Reduce the attenuation depth if spectral holes remain audible.
  3. Relearn if the noise profile included wanted audio.

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

05 / Get unstuck

Small details that matter.

  • Raising the threshold makes fewer frequency regions pass.
  • A deep reduction can create unnatural gaps in the spectrum.