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FATHOM · ReverbProcessor parameters

31 parameters across 4 groups.

MODE

ParameterIDRangeDefaultAuto
Mode
Reverb engine: 0 = Algorithmic, 1 = Convolution, 2 = Hybrid.
reverbMode0–20yes
Early Length
Length of the IR-derived early-reflection window used in Hybrid mode.
hybridEarlyLengthMs10–300 ms80 msyes

ALGORITHMIC

ParameterIDRangeDefaultAuto
Mix
Dry/wet balance for the algorithmic reverb engine.
mix0–11yes
Size
Room-size multiplier; 1.0 is the reference room size.
reverbSizeParam0.2–31yes
Decay
Reverb tail decay time.
reverbDecaySeconds0.1–30 s2 syes
Pre-Delay
Delay before the reverb tail begins.
reverbPreDelayMs0–200 ms20 msyes
HF RT Mult
High-frequency decay-time multiplier relative to Decay.
reverbHighRatio0.2–10.6yes
HF Crossover
Crossover point above which HF RT Mult applies.
reverbHighCrossoverHz500–15000 Hz4500 Hzyes
LF RT Mult
Low-frequency decay-time multiplier relative to Decay.
reverbLowRatio0.2–41.3yes
LF Crossover
Crossover point below which LF RT Mult applies.
reverbLowCrossoverHz50–2000 Hz400 Hzyes
Diffusion
Echo density build-up rate — higher smears reflections together faster.
reverbDiffusion0–10.65yes
Density
Density of the late reverb tail's reflections.
reverbDensity0–10.85yes
Mod Depth
Depth of internal modulation applied to the late tank, reduces metallic ringing.
reverbModDepth0–10.35yes
Mod Rate
Rate of the late tank's internal modulation.
reverbModRateHz0.05–2 Hz0.4 Hzyes
Early Level
Level of early reflections in the mix.
reverbEarlyLevel0–10.5yes
Late Level
Level of the late reverb tail in the mix.
reverbLateLevel0–11yes
Roll Off
High-frequency roll-off point for the reverb tail.
reverbRollOffHz80–20000 Hz12000 Hzyes
VLF Cut
Very-low-frequency cut applied to the reverb tail, keeps sub content out of the wash.
reverbVlfCutDb-18–0 dB0 dByes
Character
Reverb voicing preset: 0 = Default, 1 = Plate, 2 = Hall, 3 = Room, 4 = Spring, 5 = Shimmer.
reverbCharacter0–50yes
Shimmer
Amount of a pitch-shifted (+1 octave) feedback tap injected into the late reverb tank.
reverbShimmerAmount0–10yes

CONVOLUTION

ParameterIDRangeDefaultAuto
Impulse
Index into the bundled impulse-response library — 216 real IRs (38 Voxengo + 45 AK + 134 M7, as of 2026-08-31).
irIndex0–2160yes
Conv Pre-Delay
Delay before the convolution IR begins.
convPreDelayMs0–200 ms0 msyes
Conv Mix
Dry/wet balance for the convolution engine.
convMix0–11yes
Conv Width
Stereo width of the convolved signal. 0 = mono, 1 = natural, 2 = extra wide.
convWidth0–21yes
Conv Low Cut
High-pass filter applied to the convolved signal.
convLowCutHz20–2000 Hz20 Hzyes
Conv High Cut
Low-pass filter applied to the convolved signal.
convHighCutHz1000–20000 Hz20000 Hzyes

OUTPUT

ParameterIDRangeDefaultAuto
Width
Global output-stage stereo width, applied after whichever mode ran. 0 = mono, 1 = natural, 2 = extra wide.
outputWidthAmount0–21yes
Freeze Tail
Freezes the current reverb tail indefinitely.
freezeTail0–10yes
Input
Input trim before any mode-specific processing.
inputGainDb-24–24 dB0 dByes
Output
Output trim after all processing.
outputGainDb-24–24 dB0 dByes
Bypass
Host-visible bypass — wired to the plugin's real bypass parameter, so a DAW's native bypass control and Fathom's on-screen toggle drive the same parameter.
bypass0–10yes