831 Hz Wavelength

How Long Is a 831 Hz Wavelength?

A 831 Hz sound wave has a wavelength of 0.41 meters, 41.3 cm, 1.36 feet (1 feet and 4.26 inches) or 16.26 inches when traveling in air at 20°C (68°F).

The formula for the wavelenght is λ = c/f where:

  • c is the celerity (speed) of sound = 343.21 m/s or 1126.03 ft/s in air at 20°C (68°F).
  • f is the frequency = 831 Hz
which gives a wavelength λ of 0.41 meters, or 1.36 feet.

831 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 831 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 831 Hz wavelength (cm)831 Hz wavelength (in)
-40-4036.833014.5012
-35-3137.225914.6559
-30-2237.614614.8089
-25-1337.999414.9604
-20-438.380315.1104
-15538.757515.2589
-101439.131015.4059
-52339.501115.5516
03239.867615.6959
54140.230915.8389
105040.590815.9806
155940.947716.1211
206841.301416.2604
257741.652116.3985
308641.999916.5354
359542.344916.6712
4010442.687016.8059

831 Hz Half Wavelength and Standing Waves

The half wavelength of a 831 Hz sound wave is 0.21 meters, 20.65 cm, 0.68 feet (0 feet and 8.13 inches) or 8.13 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 831 Hz in rooms where two opposing walls (axial mode), edges (tangential mode) or corners (oblique mode) are spaced by a distance d = nλ/2 where:

  • n is a natural (positive integer greater than or equal to 1)
  • λ is the 831 Hz wavelength = 0.41 meters, or 1.36 feet in air at 20°C (68°F).

831 Hz Standing Waves Distances

n Distance (m) Distance (ft)
10.210.68
20.411.36
30.622.03
40.832.71
51.033.39

We typically don't treat rooms for standing waves above 300 Hz.

Given the relatively small 831 Hz half wavelength, you can treat your room by using thick acoustic foam. This will absorb frequencies as low as 250 Hz, and all the way up to 20,000 Hz.

How To Convert 831 Hz To ms

A Hz (Hertz) is a cycle (or period) per second.

Because a 831 Hz wave will ocillate 831 times per second, we can find the time of a single cycle (or period) with the formula p = 1/f where:

  • f is the frequency of the wave = 831 Hz

The result will be expressed in seconds, so let's multiply by 1000 to get miliseconds:

1 / 831 Hz * 1000 = 1.2 ms.