429 Hz Wavelength

How Long Is a 429 Hz Wavelength?

A 429 Hz sound wave has a wavelength of 0.8 meters, 80 cm, 2.62 feet (2 feet and 7.5 inches) or 31.5 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 = 429 Hz
which gives a wavelength λ of 0.8 meters, or 2.62 feet.

429 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 429 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 429 Hz wavelength (cm)429 Hz wavelength (in)
-40-4071.347928.0897
-35-3172.108928.3893
-30-2272.861928.6858
-25-1373.607328.9792
-20-474.345129.2697
-15575.075729.5574
-101475.799329.8422
-52376.516030.1244
03277.226130.4040
54177.929730.6810
105078.627030.9555
155979.318231.2276
206880.003431.4974
257780.682831.7649
308681.356532.0301
359582.024732.2932
4010482.687532.5541

429 Hz Half Wavelength and Standing Waves

The half wavelength of a 429 Hz sound wave is 0.4 meters, 40 cm, 1.31 feet (1 feet and 3.75 inches) or 15.75 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 429 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 429 Hz wavelength = 0.8 meters, or 2.62 feet in air at 20°C (68°F).

429 Hz Standing Waves Distances

n Distance (m) Distance (ft)
10.401.31
20.802.62
31.203.94
41.605.25
52.006.56

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

Given the relatively small 429 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 429 Hz To ms

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

Because a 429 Hz wave will ocillate 429 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 = 429 Hz

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

1 / 429 Hz * 1000 = 2.33 ms.