218 Hz Wavelength

How Long Is a 218 Hz Wavelength?

A 218 Hz sound wave has a wavelength of 1.57 meters, 157.44 cm, 5.17 feet (5 feet and 1.98 inches) or 61.98 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 = 218 Hz
which gives a wavelength λ of 1.57 meters, or 5.17 feet.

218 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 218 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 218 Hz wavelength (m)218 Hz wavelength (ft)
-40-401.40404.6065
-35-311.41904.6556
-30-221.43384.7042
-25-131.44854.7523
-20-41.46304.8000
-1551.47744.8471
-10141.49164.8939
-5231.50584.9401
0321.51974.9860
5411.53365.0314
10501.54735.0764
15591.56095.1210
20681.57445.1653
25771.58775.2091
30861.60105.2526
35951.61425.2958
401041.62725.3386

218 Hz Half Wavelength and Standing Waves

The half wavelength of a 218 Hz sound wave is 0.79 meters, 78.72 cm, 2.58 feet (2 feet and 6.99 inches) or 30.99 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 218 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 218 Hz wavelength = 1.57 meters, or 5.17 feet in air at 20°C (68°F).

218 Hz Standing Waves Distances

n Distance (m) Distance (ft)
10.792.58
21.575.17
32.367.75
43.1510.33
53.9412.91
64.7215.50
75.5118.08
86.3020.66
97.0823.24
107.8725.83
118.6628.41
129.4530.99
1310.2333.57
1411.0236.16
1511.8138.74
1612.6041.32
1713.3843.90
1814.1746.49
1914.9649.07
2015.7451.65

Given the relatively large 218 Hz half wavelength, standing waves will occur at that frequency in small listening rooms.

You can try to minimze the room modes at 218 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 218 Hz To ms

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

Because a 218 Hz wave will ocillate 218 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 = 218 Hz

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

1 / 218 Hz * 1000 = 4.59 ms.