631 Hz Wavelength

How Long Is a 631 Hz Wavelength?

A 631 Hz sound wave has a wavelength of 0.54 meters, 54.39 cm, 1.78 feet (1 feet and 9.41 inches) or 21.41 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 = 631 Hz
which gives a wavelength λ of 0.54 meters, or 1.78 feet.

631 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 631 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 631 Hz wavelength (cm)631 Hz wavelength (in)
-40-4048.507519.0975
-35-3149.024919.3011
-30-2249.536919.5027
-25-1350.043619.7022
-20-450.545319.8997
-15551.042020.0953
-101451.533920.2889
-52352.021220.4808
03252.504020.6709
54152.982320.8592
105053.456421.0458
155953.926321.2308
206854.392221.4142
257754.854121.5961
308655.312121.7764
359555.766421.9553
4010456.217022.1327

631 Hz Half Wavelength and Standing Waves

The half wavelength of a 631 Hz sound wave is 0.27 meters, 27.2 cm, 0.89 feet (0 feet and 10.71 inches) or 10.71 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 631 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 631 Hz wavelength = 0.54 meters, or 1.78 feet in air at 20°C (68°F).

631 Hz Standing Waves Distances

n Distance (m) Distance (ft)
10.270.89
20.541.78
30.822.68
41.093.57
51.364.46

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

Given the relatively small 631 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 631 Hz To ms

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

Because a 631 Hz wave will ocillate 631 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 = 631 Hz

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

1 / 631 Hz * 1000 = 1.58 ms.