Skip to guide
← Tool guides

Audio, explained · 07 / 36

Gate / Expander

Turn down quiet gaps between wanted sounds.

Visual walkthrough7 configuration controlsSynced audio walkthrough
See how it works ↓

Attack opens the gate. Hold keeps it open briefly after the level falls. Release closes it gradually. Hysteresis separates opening and closing thresholds to reduce chatter.

01 / Understand

The idea, before the settings.

A gate follows level, not word meaning or frequency. Set its threshold above room noise and below your quietest intended speech. Ratio makes the transition stronger; Range limits the maximum attenuation.

MicrophoneGate / ExpanderCompressor → Output

Use it in AudioRouter

  1. Measure the background while quiet, then the quietest speech you want to keep.
  2. Set Threshold between those levels and start with a modest Range such as 20 dB.
  3. Increase Hold or Release if word endings disappear; lower Threshold if quiet words never open the gate.
  4. Use Hysteresis to stop rapid reopening near the boundary; use Ratio for gentler downward expansion.

What success looks like

Background drops during pauses while wanted phrases open the gate. A gate cannot remove noise underneath speech.

If it does not work

If it chatters, increase Hysteresis/Hold before deepening Range. If the first consonant is cut, shorten Attack or lower Threshold.

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.

Voice-like synthetic phrases sit above a quiet bed. Listen to the pauses and word tails; compare Input with the attenuated Output.

The example repeats until you press Stop, and control changes are heard immediately. The traces are drawn from that audio, and the line marks the moment you hear. This is not a DSP measurement or control for your running AudioRouter session.

03 / Configure

Every control, with a reason.

01

Threshold

thresholdDb

Opening threshold for the overall signal level.

Range / choices-80 dBFS → 0 dBFSDefault-45 dBFS

↓ Lower / alternativeOpens for quieter sound and potentially room noise.

↑ Higher / alternativeRequires louder sound to open; may remove quiet words.

Try thisPut it between measured room noise and quiet speech.

Keep in mind Hysteresis defines a lower closing boundary.

02

Range

rangeDb

Maximum gate attenuation below the open level.

Range / choices0 dB → 80 dBDefault60 dB

↓ Lower / alternativePreserves more background; 0 dB disables attenuation.

↑ Higher / alternativePermits deeper quiet-gap reduction.

Try thisTry 20 dB for a gentle expander-like result.

Keep in mind Range is a cap on reduction, not the opening threshold.

03

Attack

attackMs

How quickly the gate opens once the wanted signal crosses the opening threshold.

Range / choices0.1 ms → 100 msDefault5 ms

↓ Lower / alternativeMakes engagement faster.

↑ Higher / alternativeMakes engagement slower.

Try thisTry 2 ms; shorten it if initial consonants are being cut.

Keep in mind For Gate this is opening; for Compressor and Duck this is increasing attenuation.

04

Hysteresis

hysteresisDb

Distance below the opening threshold at which the gate may close.

Range / choices0 dB → 12 dBDefault3 dB

↓ Lower / alternativeMakes opening and closing thresholds closer.

↑ Higher / alternativeKeeps it open through larger level dips.

Try thisAt threshold −45 dBFS and hysteresis 3 dB, the closing boundary is −48 dBFS.

Keep in mind Hold and Release also affect the eventual closing motion.

05

Ratio

ratio

Downward expansion below threshold, capped by Range. Higher ratios suppress quiet material more strongly.

Range / choices1 → 20Default4

↓ Lower / alternativeApproaches unchanged dynamics at 1:1.

↑ Higher / alternativeApplies stronger level reduction.

Try thisAt 2:1, a steady input 6 dB below threshold is pushed about another 6 dB down, until Range limits reduction.

Keep in mind Gate uses reduction below its threshold; Compressor uses reduction above it.

06

Hold

holdMs

How long the gate stays open after the signal drops below its closing threshold.

Range / choices0 ms → 1000 msDefault50 ms

↓ Lower / alternativeAllows disengagement sooner.

↑ Higher / alternativeBridges longer gaps.

Try thisTry 100 ms to bridge small gaps between syllables.

Keep in mind Release follows the hold interval.

07

Release

releaseMs

How gradually the gate closes after Hold expires.

Range / choices10 ms → 2000 msDefault150 ms

↓ Lower / alternativeMakes recovery faster.

↑ Higher / alternativeMakes recovery slower.

Try thisTry 200 ms to preserve natural word tails.

Keep in mind Extremely quick changes can sound like pumping or distortion.

04 / Put it to work

Start with a useful example.

Example 1

Reduce room noise between phrases

  1. Observe room noise and quiet speech.
  2. Place threshold between the two rather than blindly using −45 dBFS.
  3. Try Range 20 dB for a gentle reduction before using deeper attenuation.
Example 2

Preserve word endings

  1. If endings disappear, increase Hold from 50 to 100 ms.
  2. Try a longer Release, such as 200 ms.
  3. Lower Threshold if quiet words never open the gate.

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

05 / Get unstuck

Small details that matter.

  • A gate cannot remove noise while your speech keeps it open.
  • A very high threshold can remove entire quiet words.
  • Range 0 dB removes attenuation while retaining gate state reporting.