1,140 Hz Wavelength

How Long Is a 1140 Hz Wavelength?

A 1140 Hz sound wave has a wavelength of 0.3 meters, 30.11 cm, 0.99 feet (0 feet and 11.85 inches) or 11.85 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 = 1140 Hz
which gives a wavelength λ of 0.3 meters, or 0.99 feet.

1140 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 1140 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 1140 Hz wavelength (cm)1140 Hz wavelength (in)
-40-4026.849310.5706
-35-3127.135710.6834
-30-2227.419110.7949
-25-1327.699610.9053
-20-427.977211.0147
-15528.252211.1229
-101428.524511.2301
-52328.794211.3363
03229.061411.4415
54129.326211.5457
105029.588611.6491
155929.848711.7515
206830.106511.8530
257730.362211.9536
308630.615712.0534
359530.867212.1524
4010431.116612.2506

1140 Hz Half Wavelength and Standing Waves

The half wavelength of a 1140 Hz sound wave is 0.15 meters, 15.05 cm, 0.49 feet (0 feet and 5.93 inches) or 5.93 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 1140 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 1140 Hz wavelength = 0.3 meters, or 0.99 feet in air at 20°C (68°F).

1140 Hz Standing Waves Distances

n Distance (m) Distance (ft)
10.150.49
20.300.99
30.451.48
40.601.98
50.752.47

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

Given the relatively small 1140 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 1140 Hz To ms

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

Because a 1140 Hz wave will ocillate 1140 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 = 1140 Hz

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

1 / 1140 Hz * 1000 = 0.88 ms.