Collapse User Manual

Version 1.0 • Predictive Sidechain Ducking Plugin

1. Introduction

What is Collapse?

Collapse is a sidechain-driven ducking plugin that allows for predictive attenuation. It ducks the track it is placed on in response to a sidechain signal, with precise control over depth, envelope shape, lookahead, and hard muting.

Transparent Ducking

Shape the ducking envelope with independent Attack, Hold, and Release controls and six release curves for natural or aggressive recovery.

Broadband & Spectral Modes

Broadband ducks the full spectrum. Spectral only attenuates the frequencies actually present in the sidechain, leaving the rest of the signal untouched.

Pre-Transient Muting

A dedicated mute window fires a hard silence at the begining of the ducking envelope, giving you full silence that a volume envelope alone cannot accomplish. This can be combined with lookahead to enable pre-transient ducking.

Lookahead

Up to 25 ms of lookahead so the envelope can begin descending before the sidechain transient arrives.

System Requirements

  • macOS 10.13+ or Windows 10+
  • VST3 or AU compatible DAW with sidechain routing
  • 64-bit processor

2. Quick Start

  1. Instantiate Collapse on the track you want to duck (the target).
  2. Drag and drop the sidechain source onto the plugin UI.
  3. Adjust the envelope (Amount, Attack, Hold, Release), Lookahead, and Mute to taste.
  4. Choose Broadband (default) or Spectral mode depending on whether you want full-spectrum or frequency-selective ducking.
The default settings produce audible ducking the moment a sidechain source is dropped in. Start there and adjust only what you need.

3. Interface Overview

Header

  • Mode toggle: Broadband (default) or Spectral
  • Sidechain node — lights up when a sidechain signal is detected

Sidechain Drop Zone

  • Drag any track from your DAW onto this area to assign it as the sidechain source
  • Per-sidechain highpass and lowpass filters shape which frequencies trigger the duck

Envelope Controls

  • Amount, Attack, Hold, Release knobs
  • Lookahead and Mute controls

Output

  • Output Gain for makeup adjustment after ducking

4. Control Reference

1 Amount

Purpose: Controls how far the signal is attenuated when the sidechain triggers.

Range: 0–100%

  • 0% — no ducking
  • 100% — full reduction to silence at peak

2 Attack

Purpose: Time for the ducker to reach full depth once the sidechain triggers.

Range: 0–10 ms

  • 0 ms — sample-accurate instantaneous attack
  • Longer values soften the onset of the duck

3 Hold

Purpose: Holds the envelope at full depth after the sidechain stops triggering, before release begins.

Range: 0–50 ms

4 Release

Purpose: Time to return to unity after the hold stage.

Range: 10–2000 ms

Release Shapes

Click the release label to pick a curve shape:

Shape Character
LinearStraight-line recovery
ExponentialFast initial release, slowing into unity
LogarithmicSlow initial release, accelerating
S-CurveSmooth at both ends, steep in the middle
Hold + ReleasePlateau at depth before releasing
Punch (default)Ultra-tight recovery for maximum transient punch-through

Tempo Sync

Click the release value to lock it to host tempo. Available divisions: 1/32T, 1/32, 1/16T, 1/32D, 1/16, 1/8T, 1/16D, 1/8, 1/4T, 1/8D, 1/4, 1/4D.

5 Lookahead

Purpose: Pre-delays the target signal so the envelope can begin descending before the sidechain transient.

Range: 0–25 ms

Lookahead is cumulative across nested routing. See Key Concepts before applying it to multiple instances.

6 Mute

Purpose: Inserts a hard silence window at the peak of the duck with short fade-in/out ramps to prevent clicks.

Range: 1–50 ms (default 5 ms)

  • Click the Mute label to enable or disable
  • Drag the knob to set duration
Mute is the most effective way to get full pre-transient space. See Key Concepts for why.

7 Broadband / Spectral Toggle

Purpose: Selects the ducking algorithm.

  • Broadband (default) — attenuates the whole spectrum equally. Near-zero processing latency.
  • Spectral — attenuates only the frequencies actually present in the sidechain. Introduces ~46 ms of FFT latency.

8 Sidechain Filters

Purpose: Shape which part of the sidechain signal triggers ducking.

Ranges

  • Highpass: 20–2000 Hz (default 100 Hz)
  • Lowpass: 20–20000 Hz (default 10 kHz)
  • Slopes: 12, 24, or 48 dB/oct

9 Output Gain

Purpose: Global makeup gain at the output stage.

Range: −12 to +12 dB

5. Key Concepts

Lookahead Is Cumulative Across Instances

Lookahead works by pre-delaying the target signal so the ducking envelope can begin before the sidechain transient. Your DAW compensates for this latency on the track where Collapse is placed, but the compensation adds up through nested routing.

If you have multiple instances of Collapse on tracks that feed each other (for example, a bus that is itself routed through another bus), the total reported latency stacks. This can pull audio out of time with the rest of the project.

Rule of thumb: apply lookahead at only one level of the routing chain per project. Leave lookahead at 0 ms on all other Collapse instances in the same nested path.

Use Mute for Full Pre-Transient Ducking

Even at maximum lookahead, the ducking envelope still takes time to reach full depth (set by Attack). That means the envelope can only precede the sidechain transient by a few milliseconds of meaningful reduction — not full silence.

The Mute window bypasses this by inserting a hard silence at the peak of the duck. If your goal is complete space in front of a transient (for example, tight kick-on-bass ducking), Mute is the correct tool. Pair it with enough lookahead to position the silence where you need it.

6. Broadband vs. Spectral

Mode Behavior Latency Best For
Broadband (default) Attenuates the full spectrum equally ~0 ms Kick-on-bass, pumping effects, general ducking
Spectral Only ducks frequencies present in the sidechain ~46 ms (FFT) Vocal-over-music, surgical frequency clearing
Use Broadband unless you specifically need the sidechain to carve its own frequencies out of the target. Spectral is a scalpel; Broadband is the workhorse.

7. Troubleshooting

No ducking is heard

  • Confirm a sidechain source has been dragged onto the UI and the sidechain node is lit
  • Check that Amount is above 0%
  • Verify the sidechain filters aren't rejecting the frequencies present in your source

Timing feels smeared or off

  • Check for multiple Collapse instances in a nested routing chain — lookahead stacks across them
  • Apply lookahead on only one instance per routing path
  • Confirm your DAW's plugin delay compensation is enabled

Ducking does not fully precede the transient

  • The envelope is limited by Attack time even at maximum lookahead
  • Enable the Mute window for a hard silence at the peak of the duck

Clicks at the edge of the mute window

  • Collapse applies a 0.5 ms fade at each edge automatically — if clicks persist, reduce the Mute length slightly and let Attack/Release handle the surrounding transition

License & Copyright

Collapse is copyright Enzyme Technologies LLC 2026. All rights reserved.

This manual reflects Collapse version 1.0.0.