Ableton/Live/UG/31 Instrument Reference/02 Collision
- Collision models mallet percussion with physical modeling, made with Applied Acoustics Systems. It can model real objects or ones that couldn't exist.
- Two exciters, Mallet and Noise, feed two stereo resonators that can be independent or linked. The exciters start the sound; the resonators shape most of its character. With both exciters off there is no sound.
- The interface has Mallet and Noise sections; Resonator 1 and Resonator 2 tabs; an LFO tab with two LFOs; a MIDI/MPE tab for pitch bend, mod wheel, aftertouch and their MPE versions; and global settings for voices, retrigger, resonator structure and volume.
- Turning off unused sections saves CPU.
- Simulates a mallet striking a surface; the controls set the mallet's physical properties. The Mallet button turns it on.
- Volume — output level.
- Stiffness — soft mallets give fewer highs and a longer, blurrier hit; harder ones a shorter, brighter hit.
- Noise — impact noise in each strike, like the "chiff" of a felt mallet.
- Color — noise frequency; higher removes lows. No effect when Noise is 0.
- Volume, Stiffness and Noise can follow pitch and velocity through the Key and Vel sliders in the MIDI tab.
- A second exciter: white noise through a multimode filter with its own envelope, usable instead of or with the Mallet. The Noise button turns it on.
- Filter types LP, HP, BP and LP+HP. Freq sets cutoff or center; Res sets resonance, or bandwidth in LP+HP. Cutoff can follow note pitch, velocity or the envelope.
- Volume — output level, modulated by pitch and velocity in the MIDI tab.
- Env Amt with A, D, S, R — an ADSR envelope on the filter. S at 0 removes sustain; at 100 removes decay.
- The resonators define most of the sound. Each tab has an on switch; with both off there is no sound.
- Resonance Type:
- Beam — beams of various materials and sizes.
- Marimba — a Beam variant with the overtone tuning of arch-cut marimba bars.
- String — strings of various materials and sizes.
- Membrane — a rectangular membrane like a drum head.
- Plate — a flat rectangular plate.
- Pipe — a tube open at one end with an adjustable opening at the other.
- Tube — a tube closed at both ends.
- Quality — Eco to High, trading overtone detail for CPU. Not on Pipe or Tube.
- 1 → 2 / 2 → 1 — copy one resonator's settings to the other.
- X-Y Controller — horizontal sets decay, vertical sets Material or Radius.
- Decay — internal damping.
- Material — low values let lows ring longer (wood, rubber, nylon); high values let highs ring longer (glass, metal). Pipe and Tube use Radius instead: larger means longer decay and more sustained highs, and at extremes a pitch change.
- Ratio (Membrane, Plate) — proportion of the object's two sides.
- Brightness — louder highs at higher values. Not on Pipe or Tube.
- Inharm — negative compresses partials downward, positive stretches them upward. Not on Pipe or Tube.
- Opening (Pipe) — 0% closed at one end, 100% open at both.
- Hit — strike point, center at 0% toward the edge at higher values; Rnd randomizes it. Not on Pipe or Tube.
- Note Off — how much note-off mutes the resonance; 0% ignores it like a real marimba, 100% mutes at once.
- Pos. L / Pos. R — where vibrations are picked up on each side, center to edge. Pipe and Tube are always measured at the open end.
- Decay, Material/Radius, Inharm and Opening can be modulated in the MIDI tab.
31.2.4.1 Tuning Section
- Tune in semitones and Fine in cents, up to ±50.
- Key in the MIDI tab sets keyboard tracking: 100% is equal temperament, 200% makes each half step a whole step, negative values fall in pitch as you play higher.
- Pitch Env and Time — a starting pitch that glides to the final pitch; velocity can scale the start.
31.2.4.2 Mixer Section
- Gain and Pan per resonator; pan can follow note pitch.
- Bleed — mixes in the dry exciter signal, which helps restore highs lost at low tuning or quality.
- Two LFOs modulate Mallet, Noise and resonator parameters, and each other.
- Waveforms: sine, square, triangle, saw up, saw down, stepped noise and smooth noise.
- Offs. — phase offset, used when Retrigger restarts the LFO on each note.
- Two Destination choosers per LFO, each with an amount relative to the LFO's Amount.
- Rate in Hz or synced divisions; Rate can follow pitch and Amount velocity in the MIDI tab.
- Maps pitch bend (including per-note), mod wheel, pressure and slide to two destinations each, with amounts.
- Key and Vel sliders let note pitch and velocity modulate further Mallet, Noise, resonator and LFO parameters.
31.2.6.1 The Global Section
- Voices — maximum polyphony.
- Retrig. — retriggers a playing note instead of adding a voice, saving CPU.
- Structure — 1 > 2 (serial): both exciters feed Resonator 1, whose mono mix also feeds Resonator 2 while Resonator 1 reaches its own mixer in stereo. 1 + 2 (parallel): the exciter mix feeds both resonators.
- Volume — overall output.
- For a realistic marimba, follow the physical chain: the Mallet strikes a tuned bar (Resonator 1), and a tube (Resonator 2) amplifies it, in serial 1 > 2.
- For unrealistic sounds:
- Use the Noise exciter with long envelopes for washy, near-granular textures, or effects like bowed vibraphone and crystal glasses.
- Try the parallel 1 + 2 structure.
- Modulate with the LFOs and MIDI or MPE controllers.
- The models are idealized and can respond far more strongly than real objects. Some settings jump sharply in volume, so keep levels low while experimenting.
