Slight pitch offset between two identical synth voices creates beating and perceptual thickness

Playing two copies of the same synth at almost-but-not-identical pitches creates amplitude modulation via beating — the two slightly different frequencies reinforce and cancel periodically. At detune values near 0 this sounds thick and double-tracked; at larger values it sounds out of tune. This technique is built into synths like :dsaw, :dpulse, and :dtri which expose a detune: opt. Detuned unison is the source of the classic supersaw sound used in trance and EDM.

Examples

synth :square, note: :e3 synth :square, note: :e3 + 0.1 # slight detune produces beating/thickness

Assessment

Describe what you hear as detune increases from 0 to 1. Identify the perceptual boundary between ‘thick’ and ‘out of tune’. Then use the :dsaw synth’s built-in detune: opt.