9,820 Hz Wavelength

How Long Is a 9820 Hz Wavelength?

A 9820 Hz sound wave has a wavelength of 0.03 meters, 3.5 cm, 0.11 feet (0 feet and 1.38 inches) or 1.38 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 = 9820 Hz
which gives a wavelength λ of 0.03 meters, or 0.11 feet.

9820 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 9820 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 9820 Hz wavelength (cm)9820 Hz wavelength (in)
-40-403.11691.2271
-35-313.15021.2402
-30-223.18311.2532
-25-133.21561.2660
-20-43.24791.2787
-1553.27981.2913
-10143.31141.3037
-5233.34271.3160
0323.37371.3282
5413.40451.3403
10503.43491.3523
15593.46511.3642
20683.49511.3760
25773.52471.3877
30863.55421.3993
35953.58341.4108
401043.61231.4222

9820 Hz Half Wavelength and Standing Waves

The half wavelength of a 9820 Hz sound wave is 0.02 meters, 1.75 cm, 0.06 feet (0 feet and 0.69 inches) or 0.69 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 9820 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 9820 Hz wavelength = 0.03 meters, or 0.11 feet in air at 20°C (68°F).

9820 Hz Standing Waves Distances

n Distance (m) Distance (ft)
10.020.06
20.030.11
30.050.17
40.070.23
50.090.29

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

Given the relatively small 9820 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 9820 Hz To ms

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

Because a 9820 Hz wave will ocillate 9820 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 = 9820 Hz

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

1 / 9820 Hz * 1000 = 0.1 ms.