How this calculation works
Two audio paths can reach a listener at different times because of both acoustic travel and processing latency. The faster path is delayed to meet the slower one; a causal delay cannot make the slower path arrive earlier.
Arrival ms = 1000 × distance/sound speed + electronic latency; add the positive arrival difference to the faster pathA worked example
At the model’s zero-degree reference, sound speed is 331.3 m/s. A 3.313 m distance difference with equal electronic latency produces ten milliseconds of arrival difference. The shorter path needs ten milliseconds added. At 48000 Hz that is 480 samples. Entering ten extra milliseconds on the longer path would increase the mismatch rather than fix it.
Good to know
Two-path straight-line dry-air timing only; no room reflection, latency detection, broadband phase match or multi-seat alignment. Use appropriate measurements for an installed system. This page calculates a timing scenario and does not certify acoustic performance.
Reference: OpenStax — sound speed and temperature (opens in a new tab) ↗
What this calculation answers
Two audio paths can reach a listener at different times because of both acoustic travel and processing latency. The faster path is delayed to meet the slower one; a causal delay cannot make the slower path arrive earlier.
This page keeps acoustic and electronic contributions separate for two paths to one selected receiver. It does not measure latency or determine where a microphone or loudspeaker is located.
The Speaker distance and combined sound level calculator estimates direct levels under an incoherent-source assumption. Arrival alignment can make coherence important, so this timing result does not validate that incoherent level sum.
Use the right input conventions
Distances are straight-line path lengths in metres. Electronic latencies are supplied milliseconds, measured or justified for the relevant devices and settings. Use a common reference for both paths.
Sound speed uses a dry-air ideal temperature relation with 331.3 m/s at zero degrees. Humidity, wind and reflections are not modeled. Sample rate converts the final time difference to a nearest whole-sample command.
Interpret the result
Only one of the two additional-delay metrics is positive unless the arrivals already match. Changing electronic latency can reverse which acoustic path is effectively faster, even when its speaker is closer.
Time alignment at one receiver is not the same as matching broadband phase or arrival at every seat. Frequency-dependent processing and spatial geometry can require a fuller measurement-based approach.
Work through the example
At the model’s zero-degree reference, sound speed is 331.3 m/s. A 3.313 m distance difference with equal electronic latency produces ten milliseconds of arrival difference.
The shorter path needs ten milliseconds added. At 48000 Hz that is 480 samples. Entering ten extra milliseconds on the longer path would increase the mismatch rather than fix it.
Where the model stops
Two-path straight-line dry-air timing only; no room reflection, latency detection, broadband phase match or multi-seat alignment.
Use appropriate measurements for an installed system. This page calculates a timing scenario and does not certify acoustic performance.
A few questions, answered
Which path gets delayed?
The path with the earlier total arrival, after adding its acoustic and electronic terms.
Does equal arrival guarantee equal phase at every frequency?
No. Frequency-dependent response and spatial interference are beyond this timing-only model.