4,040 Hz Wavelength

How Long Is a 4040 Hz Wavelength?

A 4040 Hz sound wave has a wavelength of 0.08 meters, 8.5 cm, 0.28 feet (0 feet and 3.34 inches) or 3.34 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 = 4040 Hz
which gives a wavelength λ of 0.08 meters, or 0.28 feet.

4040 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 4040 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 4040 Hz wavelength (cm)4040 Hz wavelength (in)
-40-407.57632.9828
-35-317.65713.0146
-30-227.73713.0461
-25-137.81623.0773
-20-47.89463.1081
-1557.97223.1386
-10148.04903.1689
-5238.12513.1989
0328.20053.2285
5418.27523.2580
10508.34933.2871
15598.42273.3160
20688.49543.3447
25778.56763.3731
30868.63913.4012
35958.71003.4292
401048.78043.4569

4040 Hz Half Wavelength and Standing Waves

The half wavelength of a 4040 Hz sound wave is 0.04 meters, 4.25 cm, 0.14 feet (0 feet and 1.67 inches) or 1.67 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 4040 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 4040 Hz wavelength = 0.08 meters, or 0.28 feet in air at 20°C (68°F).

4040 Hz Standing Waves Distances

n Distance (m) Distance (ft)
10.040.14
20.080.28
30.130.42
40.170.56
50.210.70

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

Given the relatively small 4040 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 4040 Hz To ms

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

Because a 4040 Hz wave will ocillate 4040 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 = 4040 Hz

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

1 / 4040 Hz * 1000 = 0.25 ms.