427 Hz Wavelength

How Long Is a 427 Hz Wavelength?

A 427 Hz sound wave has a wavelength of 0.8 meters, 80.38 cm, 2.64 feet (2 feet and 7.64 inches) or 31.64 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 = 427 Hz
which gives a wavelength λ of 0.8 meters, or 2.64 feet.

427 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 427 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 427 Hz wavelength (cm)427 Hz wavelength (in)
-40-4071.682128.2213
-35-3172.446628.5223
-30-2273.203228.8202
-25-1373.952029.1150
-20-474.693329.4068
-15575.427429.6958
-101476.154329.9820
-52376.874430.2655
03277.587830.5464
54178.294730.8247
105078.995331.1005
155979.689731.3739
206880.378131.6449
257781.060731.9137
308681.737632.1801
359582.408932.4444
4010483.074832.7066

427 Hz Half Wavelength and Standing Waves

The half wavelength of a 427 Hz sound wave is 0.4 meters, 40.19 cm, 1.32 feet (1 feet and 3.82 inches) or 15.82 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 427 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 427 Hz wavelength = 0.8 meters, or 2.64 feet in air at 20°C (68°F).

427 Hz Standing Waves Distances

n Distance (m) Distance (ft)
10.401.32
20.802.64
31.213.96
41.615.27
52.016.59

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

Given the relatively small 427 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 427 Hz To ms

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

Because a 427 Hz wave will ocillate 427 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 = 427 Hz

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

1 / 427 Hz * 1000 = 2.34 ms.