FOAM: Physical Modeling Synth

FOAM is an attempt at opening new territory in synthesis.

Very few fundamentally new synthesis methods have emerged in the past twenty years — FM, granular, wavetable, physical modeling of struck and bowed things — the paradigms were mostly set by the early 90s. FOAM models something almost no instrument has: the acoustics of bubbles and foam.

Bubble acoustics is one of the most sonically rich phenomena in nature and one of the least explored in synthesis. The sound of a wave receding isn't five or ten things — it is thousands of simultaneous bubble interactions whose aggregate creates the texture. FOAM implements that physics directly. Not samples: actual acoustic modeling of what happens when gas meets liquid, from the initial film rupture through cavity resonance to viscous damping.

HOW IT WORKS

Each bubble is a physics equation, not a recording or a grain. FOAM models 11+ distinct acoustic stages of a bubble's life — membrane rupture, resonance, collapse, decay — and every parameter feeds the formulas live. Turn up viscosity and small bubbles die fast while large ones ring longer in the thicker liquid, as they do in nature.

PLAY BY TOUCH

The iPad edition adds a full-screen touch surface — a tonal pad layout you play directly with your fingers, octave shift built in. Full MPE: per-note pitch bend, slide and pressure map to bubble size, pitch sweep, ring time, emission rate and amplitude.

THE ENGINE

Dense foam is rendered by many voices across multiple CPU cores. A configurable CPU governor sets the ceiling for voice density — open it up on a fast iPad, or dial it back in a busy AUM session. The transition from discrete pops to continuous foam emerges naturally from the sheer number of independent interactions.

RANGE

From single droplets to dense rafts. From water to honey to mercury. From delicate rain to walls of noise — with fantasy-sized bubbles that can dip into sub-bass if you find them.

PARAMETERS

- Bubble Physics: rate, size, ring, cascade

- Realism: shimmer, natural balance, jets, mirror depth

- Texture: stereo width, magic (psychoacoustic intensity)

- Liquid Identity: 10 materials — water, seawater, glycerol, honey, mercury and more — plus manual mass, tension, viscosity

- Foam Topology: coarsening, collapse, wetness, aging

- Modulation: chaos, drift, scatter, with per-knob locking

- Surge: temporal envelope shapes

Also runs as an Audio Unit (AUv3) inside AUM, Cubasis, GarageBand and other iPad hosts.