Purpose

Reactor listens to audio and extracts reactive signals for driving visuals and parameters: level and peak, onset and transient detection, spectral features, four energy bands, and beat tracking. The audio passes through unchanged, so you can drop it inline and tap its analysis.

TouchDesigner Use

Wire audio into in and out onward as usual. Set the Reveal menu to view the reactive signals as named channels, then bind those channels to whatever you want to move. Set the band crossovers and the attack, release, and smoothing so the signals respond the way the visual needs.

Inputs And Outputs

• Input 0: in accepts mono or stereo PCM. It is required.
• Output 0: out passes the input through unchanged.

The reactive signals are read from the operator’s Reveal surface as named channels, including: level, peak, onset, onset_strength, transient, centroid, flux, flatness, rolloff, the four energy bands sub / low / mid / high, and tempo / beat_phase.

Main Controls

• Fftsize: analysis window: 512, 1024, or 2048. Larger gives finer frequency detail, smaller responds faster.
• Sensitivity: how readily onsets are detected.
• Subcross, Lowcross, Highcross: crossover frequencies that set the four energy bands.
• Attack: how fast the level signals rise.
• Release: how fast they fall.
• Smoothing: smooths the reactive signals so they do not jitter.

Notes

• Reactor is an analysis tap, not an effect: it does not change the sound.
• Use Attack, Release, and Smoothing to shape how punchy or smooth the reactive signals feel.
• The four energy bands follow the crossover settings, so tune them to the material you are reacting to.

Parameters

This operator does not expose user parameters in the extracted schema.

Catalog metadata

Roles

• transform
• analysis
• feature_extraction
• reactivity

Tags

• reactor
• analysis
• onset
• beat
• envelope
• spectral
• reactive
• vj
• visualization
• control

Search groups

• audio
• analysis
• control