2,640 Hz Wavelength

How Long Is a 2640 Hz Wavelength?

A 2640 Hz sound wave has a wavelength of 0.13 meters, 13 cm, 0.43 feet (0 feet and 5.12 inches) or 5.12 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 = 2640 Hz
which gives a wavelength λ of 0.13 meters, or 0.43 feet.

2640 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 2640 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 2640 Hz wavelength (cm)2640 Hz wavelength (in)
-40-4011.59404.5646
-35-3111.71774.6133
-30-2211.84014.6614
-25-1311.96124.7091
-20-412.08114.7563
-15512.19984.8031
-101412.31744.8494
-52312.43394.8952
03212.54924.9406
54112.66364.9857
105012.77695.0303
155912.88925.0745
206813.00065.1183
257713.11105.1618
308613.22045.2049
359513.32905.2476
4010413.43675.2900

2640 Hz Half Wavelength and Standing Waves

The half wavelength of a 2640 Hz sound wave is 0.07 meters, 6.5 cm, 0.21 feet (0 feet and 2.56 inches) or 2.56 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 2640 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 2640 Hz wavelength = 0.13 meters, or 0.43 feet in air at 20°C (68°F).

2640 Hz Standing Waves Distances

n Distance (m) Distance (ft)
10.070.21
20.130.43
30.200.64
40.260.85
50.331.07

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

Given the relatively small 2640 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 2640 Hz To ms

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

Because a 2640 Hz wave will ocillate 2640 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 = 2640 Hz

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

1 / 2640 Hz * 1000 = 0.38 ms.