331 Hz Wavelength

How Long Is a 331 Hz Wavelength?

A 331 Hz sound wave has a wavelength of 1.04 meters, 103.69 cm, 3.4 feet (3 feet and 4.82 inches) or 40.82 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 = 331 Hz
which gives a wavelength λ of 1.04 meters, or 3.4 feet.

331 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 331 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 331 Hz wavelength (cm)331 Hz wavelength (in)
-40-4092.472136.4063
-35-3193.458436.7946
-30-2294.434337.1789
-25-1395.400437.5592
-20-496.356737.9357
-15597.303638.3085
-101498.241438.6777
-52399.170339.0434
032100.090639.4058
541101.002639.7648
1050101.906340.1206
1559102.802140.4733
2068103.690240.8229
2577104.570841.1696
3086105.443941.5134
3595106.310041.8543
40104107.169042.1925

331 Hz Half Wavelength and Standing Waves

The half wavelength of a 331 Hz sound wave is 0.52 meters, 51.85 cm, 1.7 feet (1 feet and 8.41 inches) or 20.41 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 331 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 331 Hz wavelength = 1.04 meters, or 3.4 feet in air at 20°C (68°F).

331 Hz Standing Waves Distances

n Distance (m) Distance (ft)
10.521.70
21.043.40
31.565.10
42.076.80
52.598.50
63.1110.21
73.6311.91
84.1513.61
94.6715.31
105.1817.01
115.7018.71
126.2220.41
136.7422.11
147.2623.81
157.7825.51
168.3027.22
178.8128.92
189.3330.62
199.8532.32
2010.3734.02
2110.8935.72
2211.4137.42
2311.9239.12
2412.4440.82
2512.9642.52
2613.4844.22
2714.0045.93
2814.5247.63
2915.0449.33

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

Given the relatively small 331 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 331 Hz To ms

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

Because a 331 Hz wave will ocillate 331 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 = 331 Hz

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

1 / 331 Hz * 1000 = 3.02 ms.