Controls Reference

Complete parameter reference for Pressure. All 43 parameters organized by section, with exact ranges, defaults, and descriptions from source code.

Hero Section

The primary controls you'll use on every session. These are the largest and most accessible controls in the interface.

Input

Range: -12 to +12 dB
Default: 0 dB
Description: Pre-compression gain staging. Drives the detector harder at higher values.

Pressure

Range: 0-100%
Default: 35%
Description: Central compression control. Maps to threshold, ratio, attack, release, and knee per engine.

Output

Range: -12 to +12 dB
Default: 0 dB
Description: Post-compression gain staging. Sets final output level.

Tone

Range: 0-100%
Default: 35%
Description: Sidechain detection tilt. Controls SC HPF (VCA/Drums/VariMu) or emphasis (Opto). No effect on FET sidechain.

Mix

Range: 0-100%
Default: 100%
Description: Dry/wet blend for parallel compression.

Auto

Range: On / Off
Default: On
Description: Program-dependent attack and release.

Mode

Range: MIX / INST / VOCALS / DRUMS / MASTER
Default: MIX
Description: Selects the compression engine topology.

Link

Range: On / Off
Default: Off
Description: Links stereo channels for matched gain reduction.

Gain Link

Range: On / Off
Default: Off
Description: Couples the Input and Output gain knobs to move together (UI: I/O).

Parameter	Range	Default	Description
Input	-12 to +12 dB	0 dB	Pre-compression gain staging. Drives the detector harder at higher values.
Pressure	0-100%	35%	Central compression control. Maps to threshold, ratio, attack, release, and knee per engine.
Output	-12 to +12 dB	0 dB	Post-compression gain staging. Sets final output level.
Tone	0-100%	35%	Sidechain detection tilt. Controls SC HPF (VCA/Drums/VariMu) or emphasis (Opto). No effect on FET sidechain.
Mix	0-100%	100%	Dry/wet blend for parallel compression.
Auto	On / Off	On	Program-dependent attack and release.
Mode	MIX / INST / VOCALS / DRUMS / MASTER	MIX	Selects the compression engine topology.
Link	On / Off	Off	Links stereo channels for matched gain reduction.
Gain Link	On / Off	Off	Couples the Input and Output gain knobs to move together (UI: I/O).

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Precision Controls

Classic compression parameters. These override the PRESSURE knob's automatic mapping when you need manual control.

Threshold

Range: -60 to 0 dB
Default: -20 dB
Description: Level above which compression begins.

Ratio

Range: 1:1 to 20:1
Default: 4:1
Description: Gain reduction amount above threshold.

Attack

Range: 0.1-100 ms
Default: 10 ms
Description: How quickly compression engages. Log-skewed (0.3) for precision at low values.

Release

Range: 10-1000 ms
Default: 100 ms
Description: How quickly compression releases. Log-skewed (0.4).

Makeup

Range: -6 to +6 dB
Default: 0 dB
Description: Fine gain trim (0.01 dB precision). Works with Output for dual gain staging.

Knee

Range: 0-48 dB
Default: 6 dB
Description: Soft knee width. 0 = hard knee, 48 = saturation territory.

Hold

Range: 0-500 ms
Default: 0 ms
Description: Delays release onset to preserve punch. Log-skewed (0.5).

Range

Range: -60 to 0 dB
Default: 0 dB (off)
Description: Maximum gain reduction limit. 0 = unlimited.

HPF

Range: On / Off
Default: Off
Description: Sidechain high-pass filter toggle.

SC HPF Hz

Range: 20-300 Hz
Default: 120 Hz
Description: Sidechain HPF frequency.

Ratio Limit

Range: On / Off
Default: Off
Description: Caps ratio at safe maximum for the current engine.

Parameter	Range	Default	Description
Threshold	-60 to 0 dB	-20 dB	Level above which compression begins.
Ratio	1:1 to 20:1	4:1	Gain reduction amount above threshold.
Attack	0.1-100 ms	10 ms	How quickly compression engages. Log-skewed (0.3) for precision at low values.
Release	10-1000 ms	100 ms	How quickly compression releases. Log-skewed (0.4).
Makeup	-6 to +6 dB	0 dB	Fine gain trim (0.01 dB precision). Works with Output for dual gain staging.
Knee	0-48 dB	6 dB	Soft knee width. 0 = hard knee, 48 = saturation territory.
Hold	0-500 ms	0 ms	Delays release onset to preserve punch. Log-skewed (0.5).
Range	-60 to 0 dB	0 dB (off)	Maximum gain reduction limit. 0 = unlimited.
HPF	On / Off	Off	Sidechain high-pass filter toggle.
SC HPF Hz	20-300 Hz	120 Hz	Sidechain HPF frequency.
Ratio Limit	On / Off	Off	Caps ratio at safe maximum for the current engine.

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Flavor Controls

Tonal character applied after compression. All default to 0% (off) - add to taste.

WIDTH

Range: 0-100%
Default: 0%
Description: Stereo image widening. Enhances the stereo field after compression.

Round

Range: 0-100%
Default: 0%
Description: Transient softening. Rounds sharp edges for smoother dynamics.

Air

Range: -100% to +100%
Default: 0% (center-detent)
Description: Bipolar HF tone shaping. Positive values brighten via a high-shelf exciter; negative values darken via an HF-cut path. Centre is true neutral with a tactile detent for return-to-zero. Pair small positive amounts with bus compression for sheen, or small negative amounts to tame harsh top end without an external EQ.

LF Relax

Range: 0-100%
Default: 0%
Description: Relaxes the detector at low frequencies. Reduces how much bass content drives the compressor - kick and sub trigger less gain reduction, preserving low-end punch while letting mid and high transients dominate. Drawmer 1973 canon at max; pair with the SC Low Gain and Freq shelves for surgical Pro-C-style detector shaping.

Auto Gain

Range: On / Off
Default: Off
Description: Automatic makeup gain to compensate for compression.

Drive

Range: 0-100%
Default: 0%
Description: Saturation intensity. Scales per-engine harmonic character - 0% is clean, higher adds warmth and body.

Parameter	Range	Default	Description
WIDTH	0-100%	0%	Stereo image widening. Enhances the stereo field after compression.
Round	0-100%	0%	Transient softening. Rounds sharp edges for smoother dynamics.
Air	-100% to +100%	0% (center-detent)	Bipolar HF tone shaping. Positive values brighten via a high-shelf exciter; negative values darken via an HF-cut path. Centre is true neutral with a tactile detent for return-to-zero. Pair small positive amounts with bus compression for sheen, or small negative amounts to tame harsh top end without an external EQ.
LF Relax	0-100%	0%	Relaxes the detector at low frequencies. Reduces how much bass content drives the compressor - kick and sub trigger less gain reduction, preserving low-end punch while letting mid and high transients dominate. Drawmer 1973 canon at max; pair with the SC Low Gain and Freq shelves for surgical Pro-C-style detector shaping.
Auto Gain	On / Off	Off	Automatic makeup gain to compensate for compression.
Drive	0-100%	0%	Saturation intensity. Scales per-engine harmonic character - 0% is clean, higher adds warmth and body.

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Advanced Controls

Lookahead

Range: 0-10 ms
Default: 0 ms
Description: Anticipates transients. Adds latency equal to the value.

Delta Listen

Range: On / Off
Default: Off
Description: Solos the compression difference signal.

Detector Mode

Range: Peak / RMS
Default: Peak
Description: Peak catches transients; RMS responds to average level.

Ext Sidechain

Range: On / Off
Default: Off
Description: Triggers from external audio (channels 3-4).

Mid/Side

Range: On / Off
Default: Off
Description: Processes mid and side channels independently.

SC Listen

Range: On / Off
Default: Off
Description: Solos the sidechain detector signal. Mutually exclusive with Delta Listen (SC Listen takes priority).

Parameter	Range	Default	Description
Lookahead	0-10 ms	0 ms	Anticipates transients. Adds latency equal to the value.
Delta Listen	On / Off	Off	Solos the compression difference signal.
Detector Mode	Peak / RMS	Peak	Peak catches transients; RMS responds to average level.
Ext Sidechain	On / Off	Off	Triggers from external audio (channels 3-4).
Mid/Side	On / Off	Off	Processes mid and side channels independently.
SC Listen	On / Off	Off	Solos the sidechain detector signal. Mutually exclusive with Delta Listen (SC Listen takes priority).

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Sidechain EQ

Shapes the detector signal independently of the audio output.

SC Low Gain

Range: ±12 dB
Default: 0 dB
Description: Low shelf gain in the sidechain. Cut to prevent bass pumping.

SC Low Freq

Range: 60-400 Hz
Default: 150 Hz
Description: Low shelf corner frequency.

SC High Gain

Range: ±12 dB
Default: 0 dB
Description: High shelf gain in the sidechain. Boost for de-essing.

SC High Freq

Range: 1k-10k Hz
Default: 3000 Hz
Description: High shelf corner frequency.

Parameter	Range	Default	Description
SC Low Gain	±12 dB	0 dB	Low shelf gain in the sidechain. Cut to prevent bass pumping.
SC Low Freq	60-400 Hz	150 Hz	Low shelf corner frequency.
SC High Gain	±12 dB	0 dB	High shelf gain in the sidechain. Boost for de-essing.
SC High Freq	1k-10k Hz	3000 Hz	High shelf corner frequency.

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Metering & Visualization

GR History Window

Range: 1-10 s
Default: 5 s
Description: Time window for the GR history graph.

True Peak Hold

Range: 0-5000 ms
Default: 2000 ms
Description: How long the peak value is held before decaying.

True Peak Decay

Range: 1-60 dB/s
Default: 20 dB/s
Description: Decay rate after hold expires.

LUFS Metering

Range: On / Off
Default: On
Description: ITU-R BS.1770-4 loudness measurement. Disable to save CPU.

Parameter	Range	Default	Description
GR History Window	1-10 s	5 s	Time window for the GR history graph.
True Peak Hold	0-5000 ms	2000 ms	How long the peak value is held before decaying.
True Peak Decay	1-60 dB/s	20 dB/s	Decay rate after hold expires.
LUFS Metering	On / Off	On	ITU-R BS.1770-4 loudness measurement. Disable to save CPU.

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Processing Quality

Oversample

Options: Off / 2x / 4x / 8x
Default: 2x
Description: Realtime oversampling during playback.

Oversample (Offline)

Options: Off / 2x / 4x / 8x / 16x / 32x
Default: 8x
Description: Oversampling for bounce/render. Auto-detected via isNonRealtime.

Oversample Quality

Options: Eco / Standard / Pristine
Default: Pristine
Description: FIR filter precision tier. Eco (~80 dB stopband), Standard (~100 dB), Pristine (~120 dB). Applies to both Realtime and Offline oversampling.

Parameter	Options	Default	Description
Oversample	Off / 2x / 4x / 8x	2x	Realtime oversampling during playback.
Oversample (Offline)	Off / 2x / 4x / 8x / 16x / 32x	8x	Oversampling for bounce/render. Auto-detected via isNonRealtime.
Oversample Quality	Eco / Standard / Pristine	Pristine	FIR filter precision tier. Eco (~80 dB stopband), Standard (~100 dB), Pristine (~120 dB). Applies to both Realtime and Offline oversampling.

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