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Randozi
All wheelsTools

Sound Delay and Wavelength Calculator

Find how long sound takes to travel a distance, how far it goes in a given number of milliseconds, or how long the wave of a given frequency is. The speed of sound is shown and can be changed.

Delay

8.74636 ms

0.20991 frames at 24 fps.

Physical delay in still air, not a setting for your equipment: devices add their own latency. Confirm by listening or measuring. 343 m/s is dry air at about 20 °C; the speed rises with temperature.

How it works

  1. Choose what you want: distance to delay, delay to distance, or frequency to wavelength.
  2. Enter the value and, if needed, a second distance or a frame rate.
  3. Check the speed of sound: 343 m/s is air at about 20 °C.
  4. Read the result and copy it.

What people use it for

  • Aligning speakers

    Work out the delay to set on a rear speaker that is 12 m behind the front ones.

  • Sound and picture

    Express a distance as a fraction of a video frame at 24, 25 or 30 images a second.

  • Bass and room sizes

    Find the wavelength of 50 Hz to compare it with the length of a room.

Questions

What are the formulas?
Delay in milliseconds = 1000 × distance ÷ speed. Distance = speed × delay ÷ 1000. Wavelength = speed ÷ frequency. Frames = delay in seconds × frames per second.
Is 343 m/s always right?
It is a value for dry air at about 20 °C. The speed rises with temperature and changes slightly with humidity, so the result is indicative. You can type another speed.
Does it set the delay on my equipment?
No. It gives the physical delay in still air. Equipment has its own latency and rounding, and the right setting is the one you confirm by listening or measuring.
What are half and quarter wavelengths for?
They are simple fractions of the wave, shown for reference. The page does not claim they give an ideal position for anything.