816 Hz Wavelength

How Long Is a 816 Hz Wavelength?

A 816 Hz sound wave has a wavelength of 0.42 meters, 42.06 cm, 1.38 feet (1 feet and 4.56 inches) or 16.56 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 = 816 Hz
which gives a wavelength λ of 0.42 meters, or 1.38 feet.

816 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 816 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 816 Hz wavelength (cm)816 Hz wavelength (in)
-40-4037.510114.7678
-35-3137.910214.9253
-30-2238.306115.0811
-25-1338.697915.2354
-20-439.085915.3881
-15539.470015.5394
-101439.850415.6891
-52340.227215.8375
03240.600515.9844
54140.970416.1301
105041.337016.2744
155941.700416.4175
206842.060616.5593
257742.417816.6999
308642.772016.8394
359543.123316.9777
4010443.471717.1149

816 Hz Half Wavelength and Standing Waves

The half wavelength of a 816 Hz sound wave is 0.21 meters, 21.03 cm, 0.69 feet (0 feet and 8.28 inches) or 8.28 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 816 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 816 Hz wavelength = 0.42 meters, or 1.38 feet in air at 20°C (68°F).

816 Hz Standing Waves Distances

n Distance (m) Distance (ft)
10.210.69
20.421.38
30.632.07
40.842.76
51.053.45

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

Given the relatively small 816 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 816 Hz To ms

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

Because a 816 Hz wave will ocillate 816 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 = 816 Hz

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

1 / 816 Hz * 1000 = 1.23 ms.