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Essaim — Design Specification

Overview

Essaim (French: swarm) — 32-voice rhythmic oscillator swarm for Ableton Move. Each of the 32 pads activates an independent self-triggering rhythmic oscillator. Voices layer into polyrhythmic textures. Each voice is unique on load: randomized SVF mode (LP/BP/HP) and Q, slight parameter drift.

Architecture

  • Component type: sound_generator
  • Voices: 32 (one per pad, notes 36–67)
  • Trigger model: Toggle — first press activates rhythmic pulsing, second press silences
  • Pad → knob focus: Pressing a pad switches the 8 knobs to that voice's parameters
  • Self-triggering: Each voice has an internal clock at speed rate; on each cycle the decay envelope retriggers

Per-Voice Parameters (8 knobs, shown when pad selects voice)

Knob Param Range Description
1 Speed 0.1–40 Hz Rhythmic retrigger rate
2 Mod 0–1 Envelope → frequency modulation depth
3 Decay 5ms–2s Amplitude envelope decay time
4 Timbre 0–1 Oscillator shape morph: sine→tri→saw→square
5 Frequency 0–1 Pitch (quantized to Root Note + Scale)
6 Noisiness 0–1 Noise blend (equal-power crossfade)
7 Cutoff 0–1 SVF filter cutoff (30–18000 Hz, squared mapping)
8 Volume 0–1 Per-voice output level

Hidden/Random Per-Voice (set on create_instance, not user-controllable)

  • SVF mode: random LP (0), BP (1), or HP (2)
  • SVF Q: random 0.3–0.95
  • Initial param scatter: each voice starts with slightly randomized defaults

Global Parameters (Global page via jog wheel)

Knob Param Range Description
1 Root Note 0–11 enum C, C#, D, D#, E, F, F#, G, G#, A, A#, B
2 Scale 0–5 enum Chromatic, Major, Minor, Pentatonic, Whole Tone, Harmonic Minor
3–8 — — Reserved

UI Hierarchy

Root → Global (Root Note, Scale)
     → Voice  (Speed, Mod, Decay, Timbre, Frequency, Noisiness, Cutoff, Volume)

Voice page knobs dynamically reflect the most-recently-pressed pad's voice.

DSP Details

  • Oscillator: Phase accumulator with shape morphing (timbre param)
    • 0.0 = sine, 0.33 = triangle, 0.66 = saw, 1.0 = square
  • Envelope: Instant attack, exponential decay (decay param)
  • Filter: State-variable filter (SVF), mode/Q fixed per voice at load
  • Noise: Xorshift white noise, equal-power crossfaded with oscillator
  • Mod: Envelope output modulates oscillator frequency (FM percussion character)
  • Output: All 32 voices summed, soft-clipped via tanh, stereo (slight random pan per voice)
  • Scale quantization: Frequency param (0–1) maps to ±24 semitones from root, snapped to scale