Audio Delay Calculator
Distance ↔ milliseconds ↔ samples converter with temperature-adjusted speed of sound. Essential for speaker alignment, subwoofer delay, and delay tower time-alignment.
Delay Calculator
Convert from any one value — others calculate automatically
Results
Subwoofer Alignment
When mains and subs are physically separated, delay the closer source to align wavefronts at the audience. Based on measurement-based alignment procedure from system processor documentation.
Alignment Delay
Delay the closer source. Positive value = add delay to that source. Based on: Delay (ms) = Distance_diff / Speed_of_sound × 1000
Delay Tower Alignment
Align delay towers to main array using distance + Haas effect compensation. Standard procedure: geometric delay + 5–10 ms Haas margin so main PA arrives first and localizes the image.
Tower Delay Setting
Set delay tower processor to Total Delay. Main arrival first localizes image; tower fills level within Haas window. Verify with transfer function measurement.
Frequency ↔ Distance Converter
Linked converter — type a frequency to get its wavelength, or type a distance (in m or ft) to get the corresponding frequency. Uses your temperature/humidity speed of sound settings above. All three fields are linked — changing one updates the others.
Results — each row shows wavelength (m and ft) and its corresponding frequency
Formula: c = f × λ where c = speed of sound. Half-cycle frequency = the cancellation frequency for that path-length difference (e.g. two sources spaced 1.7m apart cancel at ~200 Hz). Uses your temperature/humidity speed of sound above.
How Speaker Delay Works
Sound travels at approximately 343 m/s at 20°C — but this changes with temperature. Every 1°C change alters the speed by ~0.6 m/s. At 30°C, sound travels ~349 m/s; at 10°C, ~337 m/s. That's a 3.5% difference — enough to misalign a PA by several milliseconds over typical throw distances.
The Formula
Speed of sound (m/s) = 331.3 + (0.606 × °C) + (0.0124 × %RH)
Delay (ms) = Distance (m) / Speed of Sound (m/s) × 1000
Delay (samples) = Delay (ms) × Sample Rate (kHz)Why Temperature Matters
Outdoor festivals: morning soundcheck at 12°C vs show at 28°C = ~10 ms difference at 30m throw. That's a full wavelength at 100 Hz — subs will be out of polarity if you don't recalculate.
Practical Rules of Thumb
- 1 ms ≈ 34 cm (at 20°C)
- 1 ft ≈ 0.88 ms
- 1 sample @ 48 kHz = 0.0208 ms
- Comb filtering starts when misalignment > ¼ wavelength
Subwoofer Alignment
Subs are often physically behind mains (cardioid, end-fire) or in front (ground-stacked). Measure the acoustic center of each source to the primary audience area. Delay the closer source by the path-length difference. For precision, measure with Smaart/SysTune — impulse response gives exact delay.
Delay Tower Alignment
Standard procedure: Measure distance from main PA to delay tower coverage area. Set delay = (Distance / Speed of Sound × 1000) + Haas margin (5–10 ms). The Haas margin ensures the main PA arrives first, localizing the sound image to the stage. If delay >35 ms, the tower is perceived as a distinct echo.
Frequently Asked Questions
What sample rate should I use?
Use your console/interface native sample rate. Most live desks run 48 kHz or 96 kHz. If you're sending delay values to a Dante/AES67 network, the network handles sample rate conversion — just ensure the delay time (ms) is correct.
Does humidity really matter?
Minor effect (~0.1–0.3% across 0–100% RH). Included for precision. At 30m, 100% RH vs 0% RH changes delay by ~0.1 ms. For sub alignment, it's negligible. For precision studio work, it's measurable.
How do I find the acoustic center of a speaker?
For a single driver: the voice coil. For multi-way: the acoustic center is typically between the drivers, weighted by crossover. For line arrays: use the manufacturer's specified acoustic center (usually geometric center of the array). When in doubt, measure with Smaart/SysTune — impulse response gives exact delay.
What about delay towers / fills?
Same principle. Measure distance from main PA to delay tower location. Add 10–20 ms extra (Haas effect) so the main PA arrives first and localizes the image. This tool gives the geometric delay; add your Haas margin manually.
Can I use this for studio monitor alignment?
Yes. Nearfield distances are shorter (1–2m), so errors are smaller, but the principle is identical. Many monitor controllers accept delay in samples — this tool converts for you.
What's the difference between geometric delay and Haas-aligned delay?
Geometric delay = pure distance/speed-of-sound time. Haas delay = geometric + 5–10 ms so the primary source arrives first. For subs aligning to mains: usually just geometric (whichever is closer). For delay towers: always add Haas margin so the stage (main PA) localizes the image.
Recommended Delay Processors & DSPs
Hardware I trust for live delay alignment:
- Behringer DCX2496 — budget crossover/delay, 48 kHz
- dbx DriveRack PA2 — wizard-guided alignment, 48 kHz
- Lake LM44 — touring standard, 96 kHz, linear phase
- Meyer Galileo GALAXY — high-end, networked, 96 kHz
Affiliate links — supports this toolkit at no cost to you.