660 Hz Wavelength

How Long Is a 660 Hz Wavelength?

A 660 Hz sound wave has a wavelength of 0.52 meters, 52 cm, 1.71 feet (1 feet and 8.47 inches) or 20.47 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 = 660 Hz
which gives a wavelength λ of 0.52 meters, or 1.71 feet.

660 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 660 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 660 Hz wavelength (cm)660 Hz wavelength (in)
-40-4046.376118.2583
-35-3146.870818.4531
-30-2247.360318.6458
-25-1347.844718.8365
-20-448.324319.0253
-15548.799219.2123
-101449.269519.3975
-52349.735419.5809
03250.197019.7626
54150.654319.9426
105051.107620.1211
155951.556820.2980
206852.002220.4733
257752.443820.6472
308652.881720.8196
359553.316120.9906
4010453.746921.1602

660 Hz Half Wavelength and Standing Waves

The half wavelength of a 660 Hz sound wave is 0.26 meters, 26 cm, 0.85 feet (0 feet and 10.24 inches) or 10.24 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 660 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 660 Hz wavelength = 0.52 meters, or 1.71 feet in air at 20°C (68°F).

660 Hz Standing Waves Distances

n Distance (m) Distance (ft)
10.260.85
20.521.71
30.782.56
41.043.41
51.304.27

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

Given the relatively small 660 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 660 Hz To ms

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

Because a 660 Hz wave will ocillate 660 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 = 660 Hz

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

1 / 660 Hz * 1000 = 1.52 ms.