947 Hz Wavelength

How Long Is a 947 Hz Wavelength?

A 947 Hz sound wave has a wavelength of 0.36 meters, 36.24 cm, 1.19 feet (1 feet and 2.27 inches) or 14.27 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 = 947 Hz
which gives a wavelength λ of 0.36 meters, or 1.19 feet.

947 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 947 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 947 Hz wavelength (cm)947 Hz wavelength (in)
-40-4032.321312.7249
-35-3132.666012.8606
-30-2233.007112.9949
-25-1333.344813.1279
-20-433.679013.2595
-15534.010013.3898
-101434.337813.5188
-52334.662513.6466
03234.984213.7733
54135.302913.8988
105035.618814.0231
155935.931914.1464
206836.242314.2686
257736.550114.3898
308636.855314.5100
359537.158014.6291
4010437.458214.7473

947 Hz Half Wavelength and Standing Waves

The half wavelength of a 947 Hz sound wave is 0.18 meters, 18.12 cm, 0.59 feet (0 feet and 7.13 inches) or 7.13 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 947 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 947 Hz wavelength = 0.36 meters, or 1.19 feet in air at 20°C (68°F).

947 Hz Standing Waves Distances

n Distance (m) Distance (ft)
10.180.59
20.361.19
30.541.78
40.722.38
50.912.97

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

Given the relatively small 947 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 947 Hz To ms

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

Because a 947 Hz wave will ocillate 947 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 = 947 Hz

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

1 / 947 Hz * 1000 = 1.06 ms.