321 Hz Wavelength

How Long Is a 321 Hz Wavelength?

A 321 Hz sound wave has a wavelength of 1.07 meters, 106.92 cm, 3.51 feet (3 feet and 6.09 inches) or 42.09 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 = 321 Hz
which gives a wavelength λ of 1.07 meters, or 3.51 feet.

321 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 321 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 321 Hz wavelength (cm)321 Hz wavelength (in)
-40-4095.352837.5405
-35-3196.369837.9409
-30-2297.376238.3371
-25-1398.372338.7293
-20-499.358439.1175
-155100.334939.5019
-1014101.301939.8826
-523102.259740.2597
032103.208740.6334
541104.149141.0036
1050105.081041.3705
1559106.004741.7341
2068106.920442.0947
2577107.828442.4521
3086108.728842.8066
3595109.621843.1582
40104110.507643.5069

321 Hz Half Wavelength and Standing Waves

The half wavelength of a 321 Hz sound wave is 0.53 meters, 53.46 cm, 1.75 feet (1 feet and 9.05 inches) or 21.05 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 321 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 321 Hz wavelength = 1.07 meters, or 3.51 feet in air at 20°C (68°F).

321 Hz Standing Waves Distances

n Distance (m) Distance (ft)
10.531.75
21.073.51
31.605.26
42.147.02
52.678.77
63.2110.52
73.7412.28
84.2814.03
94.8115.79
105.3517.54
115.8819.29
126.4221.05
136.9522.80
147.4824.56
158.0226.31
168.5528.06
179.0929.82
189.6231.57
1910.1633.32
2010.6935.08
2111.2336.83
2211.7638.59
2312.3040.34
2412.8342.09
2513.3743.85
2613.9045.60
2714.4347.36
2814.9749.11
2915.5050.86

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

Given the relatively small 321 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 321 Hz To ms

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

Because a 321 Hz wave will ocillate 321 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 = 321 Hz

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

1 / 321 Hz * 1000 = 3.12 ms.