Audio Delay, Lip-Sync & Speaker Time-Alignment Calculator
Acoustic Flight Time & Lip-Sync Formula
At room temperature (68°F / 20°C), sound travels at 1,125 ft/s (343 m/s) — meaning 1 foot = 0.889 ms and 1 millisecond = 1.125 ft (13.5 in). To lock in lip-sync, set your AVR audio delay to Video Display Lag (ms) − Audio DSP Latency (ms) so sound and picture arrive within the ±10 ms ITU/SMPTE imperceptible window.
27 ms AVR Lip-Sync Delay • 2.22 ms Speaker Time-Alignment
0.65 frames at 23.976 fps • 2.5 ft (0.76 m) speaker offset at 1,125 ft/s
27 ms
AVR Lip-Sync Setting
0.65 fr
Video Frame Equivalent
+2.22 ms
Closer Speaker Delay
2.5 ft
Distance Offset (0.76 m)
9.77 ms
Ref Speaker Flight Time
1,126 ft/s
Speed of Sound (343 m/s)
Video Frame Rate & Acoustic Distance Timing Reference Table
| Frame Rate / Standard | 1 Frame Duration | Acoustic Distance / Frame | Your Lip-Sync in Frames |
|---|