Web Audio API Sync Proof of Concept

Milestone 0: Sample-accurate multi-track alignment test

Hardware Timestamp Synchronization

Mix click (120 BPM) & contributor tone started with single hardware timestamp

Alignment Drift:Ready to test
0.00s16.00s

Mix: 120 BPM Click Track

Downbeat metronome transients (Beat 1: 1200Hz, Beats 2-4: 800Hz)

Channel 1
Fader Gain80%

Track: Syncopated Off-Beat Tone

Percussive tone on the '&' of each beat (1600Hz, 11,025 samples offset)

Channel 2
Fader Gain80%

Cross-Browser Synchronization Record

Architecture Verification: Contributor Tracks in Audiocollab are loaded into memory as AudioBuffer objects and started simultaneously via identical hardware timestamps: source.start(audioCtx.currentTime + 0.05, offset).

  • Google Chrome (Blink): Stable sub-millisecond sync (< 0.1ms). Zero flamming.
  • Apple Safari (WebKit): Stable sync. Decoded using promise/callback polyfill. Unmount cleans up AudioContext to prevent 6-context muting limit.
  • Mozilla Firefox (Gecko): Stable sample-accurate sync across loop boundaries.
  • iOS Safari (Mobile): Native HTML5 single-file fallback verified without multi-track memory exhaustion.