648 Hz Wavelength

How Long Is a 648 Hz Wavelength?

A 648 Hz sound wave has a wavelength of 0.53 meters, 52.97 cm, 1.74 feet (1 feet and 8.85 inches) or 20.85 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 = 648 Hz
which gives a wavelength λ of 0.53 meters, or 1.74 feet.

648 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 648 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 648 Hz wavelength (cm)648 Hz wavelength (in)
-40-4047.235018.5964
-35-3147.738818.7948
-30-2248.237318.9911
-25-1348.730719.1853
-20-449.219219.3776
-15549.702919.5681
-101450.181919.7567
-52350.656419.9435
03251.126520.1286
54151.592420.3120
105052.054020.4937
155952.511620.6739
206852.965220.8524
257753.415021.0295
308653.861021.2051
359554.303421.3793
4010454.742221.5520

648 Hz Half Wavelength and Standing Waves

The half wavelength of a 648 Hz sound wave is 0.26 meters, 26.48 cm, 0.87 feet (0 feet and 10.43 inches) or 10.43 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 648 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 648 Hz wavelength = 0.53 meters, or 1.74 feet in air at 20°C (68°F).

648 Hz Standing Waves Distances

n Distance (m) Distance (ft)
10.260.87
20.531.74
30.792.61
41.063.48
51.324.34

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

Given the relatively small 648 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 648 Hz To ms

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

Because a 648 Hz wave will ocillate 648 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 = 648 Hz

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

1 / 648 Hz * 1000 = 1.54 ms.