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Audio Modulation

Audio Modulation · screenshot coming soon

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What this node does

Audio Modulation applies one of six LFO-driven modulation effects to a track, using the matching FFmpeg filters (aphaser, flanger, chorus, vibrato, tremolo, apulsator). You pick a mode and adjust only the parameters that belong to that mode; the rest are ignored. It takes a COMFYTV_AUDIO snapshot (or a COMFYTV_VIDEO, whose audio track is used) and outputs processed COMFYTV_AUDIO plus an fx_spec. It has a ▶ Run (FFmpeg does the work). If no source is wired, it emits just the fx_spec for chaining. To feed native ComfyUI AUDIO in or out, insert a Bridge — see bridges.md.

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When to use it

  • Add movement and width to a synth or guitar with chorus or flanger.
  • Sweep a psychedelic phaser across a pad or drum loop.
  • Add pitch wobble (vibrato) or volume pulsing (tremolo/pulsator) for rhythmic texture.

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Parameters

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mode

Which effect to apply. Options: phaser (default), flanger, chorus, vibrato, tremolo, pulsator. The parameter groups below apply per mode.

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Phaser (ph_*)

  • ph_delay — sweep delay, 0.0–5.0 (default 3.0).
  • ph_decay — feedback decay, 0.0–0.99 (default 0.4).
  • ph_speed — LFO speed in Hz, 0.1–2.0 (default 0.5).
  • ph_type — LFO shape, triangular (default) or sinusoidal.

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Flanger (fl_*)

  • fl_delay — base delay in ms, 0.0–30.0 (default 0.0).
  • fl_depth — sweep depth in ms, 0.0–10.0 (default 2.0).
  • fl_regen — regeneration/feedback %, -95 to 95 (default 0).
  • fl_width — modulated delay width %, 0–100 (default 71).
  • fl_speed — LFO speed in Hz, 0.1–10.0 (default 0.5).
  • fl_shape — LFO shape, sinusoidal (default) or triangular.
  • fl_phase — L/R phase offset %, 0–100 (default 25).

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Chorus (chorus_preset)

A built-in voicing preset: single (default), double, or triple — one, two, or three delayed voices.

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Vibrato / Tremolo (lfo_*)

Shared by both modes:
  • lfo_f — modulation frequency in Hz, 0.1–20000 (default 5.0).
  • lfo_d — modulation depth, 0.0–1.0 (default 0.5). Vibrato modulates pitch; tremolo modulates volume.

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Pulsator (pu_*)

  • pu_hz — pulse rate in Hz, 0.01–100 (default 2.0).
  • pu_amount — effect amount, 0.0–1.0 (default 1.0).
  • pu_width — pulse width, 0.0–2.0 (default 1.0).
  • pu_mode — LFO waveform: sine (default), triangle, square, sawup, sawdown.

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Outputs

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Tips

  • Only the parameters for the selected mode matter — the rest are harmless but inert.
  • Phaser fixes its gains internally (in_gain=0.4, out_gain=0.74); you control it via delay/decay/speed.
  • For a subtle widening effect, chorus single is the gentlest; triple is the lushest.
  • Audio Echo — discrete delay/echo, a different way to add space.
  • Audio Stereo — widen or narrow the stereo field.
  • FX Chain — renders multiple fx_spec steps (including this one) in a single pass.