BROADCAST AUDIO · TIME ALIGNMENT

Propagation Calculator

Throw distance to arrival time, corrected for the air it travels through — temperature and humidity drive the math; altitude logs your local pressure.

Throw & Conditions

Fills temperature, humidity, altitude & pressure from live conditions where you're standing.
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50%
Est. barometric pressure — ISA model 1013.3 hPa
ARRIVAL TIME
104.9ms
Speed of sound
344.6 m/s
 
1130.8 ft/s
Feet per ms
1.131 ft
Ms per foot
0.884 ms
Rule-of-thumb (1 ms ≈ 1.13 ft, 70°F/50% RH) is spot on for these conditions.

Delay List

No positions added yet — name a distance above and hit + Add. Every row recalculates live as conditions change.

Saved Sites

No sites saved yet — conditions save locally to this device.
About the math

Speed of sound uses the Bohn (1988) formula standard in AES live-sound literature: c = 331.3 + 0.606×T + 0.0124×RH (T in °C, RH in %). Temperature dominates; humidity adds up to a few tenths of a m/s at typical stage conditions.

Barometric pressure has a negligible direct effect on the speed of sound in air — it cancels out in the ideal-gas relationship, a well-documented result in acoustic physics. Altitude here estimates your local station pressure via the International Standard Atmosphere model (P = P₀(1 − 0.0065h/288.15)^5.2559) purely so you can log real site conditions alongside a preset; it does not feed the timing math. Enter a live station reading to log the true value instead of the ISA estimate.

Arrival time is simply throw distance ÷ corrected speed of sound.

Sources: D. Bohn, “Environmental Effects on the Speed of Sound,” J. Audio Eng. Soc, 1988 · ICAO Standard Atmosphere, 1993.