100 Hz Wavelength

How Long Is a 100 Hz Wavelength?

A 100 Hz sound wave has a wavelength of 3.43 meters, 343.21 cm, 11.26 feet (11 feet and 3.12 inches) or 135.12 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 = 100 Hz
which gives a wavelength λ of 3.43 meters, or 11.26 feet.

100 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 100 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 100 Hz wavelength (m)100 Hz wavelength (ft)
-40-403.060810.0421
-35-313.093510.1492
-30-223.125810.2552
-25-133.157810.3601
-20-43.189410.4639
-1553.220710.5668
-10143.251810.6686
-5233.282510.7695
0323.313010.8694
5413.343210.9685
10503.373111.0666
15593.402811.1639
20683.432111.2603
25773.461311.3559
30863.490211.4508
35953.518911.5448
401043.547311.6381

100 Hz Half Wavelength and Standing Waves

The half wavelength of a 100 Hz sound wave is 1.72 meters, 171.61 cm, 5.63 feet (5 feet and 7.56 inches) or 67.56 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 100 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 100 Hz wavelength = 3.43 meters, or 11.26 feet in air at 20°C (68°F).

100 Hz Standing Waves Distances

n Distance (m) Distance (ft)
11.725.63
23.4311.26
35.1516.89
46.8622.52
58.5828.15
610.3033.78
712.0139.41
813.7345.04
915.4450.67

Given the relatively large 100 Hz half wavelength, standing waves will occur at that frequency in small listening rooms.

You can try to minimze the room modes at 100 Hz by trying different speaker positions, listening positions or by placing bass traps. These can absorb frequencies as low as 63 Hz.

How To Convert 100 Hz To ms

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

Because a 100 Hz wave will ocillate 100 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 = 100 Hz

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

1 / 100 Hz * 1000 = 10 ms.