Audio bands & triggers
Every reactive behaviour in SlopMotion starts from the same place: the incoming audio is split into bands, each band is watched by an adaptive threshold, and threshold crossings become binary hit events. Effects then consume those bands and events through a shared control model.
The bands
The analyser separates the signal into spectrum bands plus a few derived channels:
| Band | What it follows |
|---|---|
| Kick | Low-frequency transients — the drum that moves the floor |
| Snare | Mid-band cracks and claps |
| Hat | Short, bright transients |
| Bass | Sustained low-end energy (longer than a kick hit) |
| Vocals | Mid presence typical of vocal lines |
| Low / Mid / High | Broad spectrum thirds, for effects that want energy rather than drums |
| Beat / Rhythm | Tempo-derived pulses built from detected kick/snare onsets |
| Master | Overall level — used by gates and fades |
Thresholds are adaptive: they track the recent energy of each band, so a quiet intro and a loud drop both produce usable hits without manual re-tuning mid-set.
Each hit also carries a character — its intensity and how long the band stayed hot — so a short snare crack and a long bass swell can drive an effect differently.
The shared control model
Almost every FX parameter is audio-aware through three controls:
- Base — the resting value when the music is quiet. This is what you hear-nothing-see-something with.
- Audio depth — how much the synced band pushes on top of Base in real time. Zero means the slider is static; higher values ride the band's energy.
- Trigger — an optional band selector that makes the effect fire on hits instead of (or on top of) following energy continuously.
Order matters too: effects run as a chain, so an audio-pushed effect early in the chain changes what every later effect sees.
Trigger-only effects
Some playback effects have no meaningful "amount" — they either fire or they don't. These expose a single trigger gate instead of a Base slider:
Jump Cut, Boomerang, Stutter Back, Clip Peek, Zap, Slowmo, Accelerate, Neon Grid, Electric Noise.
Slowmo and Accelerate are a special case: the hit shapes a sustained envelope (ramp in, decay out) rather than a one-frame edge, so they feel like a push instead of a switch.
Cue Layer goes further — it is trigger-native: each cue row maps a band to a clip index and frame seek, so the trigger drives which video plays and where it lands.
Beat-driven playback
Beyond per-effect triggers, playback itself can follow the music:
- Auto-Mix trigger mode ignores the timer and advances the clip on band hits, with a configurable required hit count (e.g. every 4 kicks).
- Video Speed audio offset adds band energy on top of the base playback speed, so motion breathes with the track.
Tuning detection
The Trigger Debug overlay (Labs) shows the beat highway, live band triggers, and an event log — use it to check what the analyser hears before blaming an effect. It's a developer tool, not a show effect.