221 Hz Wavelength

How Long Is a 221 Hz Wavelength?

A 221 Hz sound wave has a wavelength of 1.55 meters, 155.3 cm, 5.1 feet (5 feet and 1.14 inches) or 61.14 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 = 221 Hz
which gives a wavelength λ of 1.55 meters, or 5.1 feet.

221 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 221 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 221 Hz wavelength (m)221 Hz wavelength (ft)
-40-401.38504.5439
-35-311.39984.5924
-30-221.41444.6404
-25-131.42884.6878
-20-41.44324.7348
-1551.45744.7813
-10141.47144.8274
-5231.48534.8731
0321.49914.9183
5411.51284.9631
10501.52635.0075
15591.53975.0515
20681.55305.0952
25771.56625.1384
30861.57935.1813
35951.59225.2239
401041.60515.2661

221 Hz Half Wavelength and Standing Waves

The half wavelength of a 221 Hz sound wave is 0.78 meters, 77.65 cm, 2.55 feet (2 feet and 6.57 inches) or 30.57 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 221 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 221 Hz wavelength = 1.55 meters, or 5.1 feet in air at 20°C (68°F).

221 Hz Standing Waves Distances

n Distance (m) Distance (ft)
10.782.55
21.555.10
32.337.64
43.1110.19
53.8812.74
64.6615.29
75.4417.83
86.2120.38
96.9922.93
107.7725.48
118.5428.02
129.3230.57
1310.0933.12
1410.8735.67
1511.6538.21
1612.4240.76
1713.2043.31
1813.9845.86
1914.7548.40
2015.5350.95

Given the relatively large 221 Hz half wavelength, standing waves will occur at that frequency in small listening rooms.

You can try to minimze the room modes at 221 Hz by trying different speaker positions, listening positions or by placing bass traps. These can absorb frequencies as low as 63 Hz.

How To Convert 221 Hz To ms

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

Because a 221 Hz wave will ocillate 221 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 = 221 Hz

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

1 / 221 Hz * 1000 = 4.52 ms.