621 Hz Wavelength

How Long Is a 621 Hz Wavelength?

A 621 Hz sound wave has a wavelength of 0.55 meters, 55.27 cm, 1.81 feet (1 feet and 9.76 inches) or 21.76 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 = 621 Hz
which gives a wavelength λ of 0.55 meters, or 1.81 feet.

621 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 621 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 621 Hz wavelength (cm)621 Hz wavelength (in)
-40-4049.288719.4050
-35-3149.814419.6120
-30-2250.334619.8168
-25-1350.849520.0195
-20-451.359220.2202
-15551.863920.4189
-101452.363820.6157
-52352.858920.8106
03253.349421.0037
54153.835521.1951
105054.317221.3847
155954.794721.5727
206855.268121.7591
257755.737421.9439
308656.202822.1271
359556.664422.3088
4010457.122322.4891

621 Hz Half Wavelength and Standing Waves

The half wavelength of a 621 Hz sound wave is 0.28 meters, 27.63 cm, 0.91 feet (0 feet and 10.88 inches) or 10.88 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 621 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 621 Hz wavelength = 0.55 meters, or 1.81 feet in air at 20°C (68°F).

621 Hz Standing Waves Distances

n Distance (m) Distance (ft)
10.280.91
20.551.81
30.832.72
41.113.63
51.384.53

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

Given the relatively small 621 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 621 Hz To ms

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

Because a 621 Hz wave will ocillate 621 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 = 621 Hz

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

1 / 621 Hz * 1000 = 1.61 ms.