How Long Is a 4 Hz Wavelength?
A 4 Hz sound wave has a wavelength of 85.8 meters, 8580.37 cm, 281.51 feet (281 feet and 6.1 inches) or 3378.1 inches when traveling in air at 20°C (68°F).
The formula for the wavelenght is λ = c/f where:
cis the celerity (speed) of sound = 343.21 m/s or 1126.03 ft/s in air at 20°C (68°F).fis the frequency = 4 Hz
λ of 85.8 meters, or 281.51 feet.
4 Hz Wavelength Depending on Temperature
The speed of sound in air depends on temperature. Here is how the wavelenght of a 4 Hz sound wave will vary according to temperature:
| Temp (°C) | Temp (°F) | 4 Hz wavelength (m) | 4 Hz wavelength (ft) |
|---|---|---|---|
| -40 | -40 | 76.5206 | 251.0520 |
| -35 | -31 | 77.3368 | 253.7296 |
| -30 | -22 | 78.1444 | 256.3793 |
| -25 | -13 | 78.9438 | 259.0019 |
| -20 | -4 | 79.7351 | 261.5983 |
| -15 | 5 | 80.5187 | 264.1691 |
| -10 | 14 | 81.2948 | 266.7151 |
| -5 | 23 | 82.0634 | 269.2370 |
| 0 | 32 | 82.8250 | 271.7356 |
| 5 | 41 | 83.5796 | 274.2113 |
| 10 | 50 | 84.3275 | 276.6650 |
| 15 | 59 | 85.0688 | 279.0970 |
| 20 | 68 | 85.8037 | 281.5081 |
| 25 | 77 | 86.5323 | 283.8986 |
| 30 | 86 | 87.2549 | 286.2692 |
| 35 | 95 | 87.9715 | 288.6204 |
| 40 | 104 | 88.6823 | 290.9525 |
4 Hz Half Wavelength and Standing Waves
The half wavelength of a 4 Hz sound wave is 42.9 meters, 4290.18 cm, 140.75 feet (140 feet and 9.05 inches) or 1689.05 inches when travelling in air at 20°C (68°F).
Modes (or standing waves) will occur at 4 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:
nis a natural (positive integer greater than or equal to 1)λis the 4 Hz wavelength = 85.8 meters, or 281.51 feet in air at 20°C (68°F).
4 Hz Standing Waves Distances
| n | Distance (m) | Distance (ft) |
|---|---|---|
| 1 | 42.90 | 140.75 |
| 2 | 85.80 | 281.51 |
| 3 | 128.71 | 422.26 |
| 4 | 171.61 | 563.02 |
| 5 | 214.51 | 703.77 |
Given the relatively large 4 Hz half wavelength, standing waves will occur at that frequency in small listening rooms.
You can try to minimze the room modes at 4 Hz by trying different speaker positions, listening positions or by placing bass traps. These can absorb frequencies as low as 63 Hz.
How To Convert 4 Hz To ms
A Hz (Hertz) is a cycle (or period) per second.
Because a 4 Hz wave will ocillate 4 times per second, we can find the time of a single cycle (or period) with the formula p = 1/f where:
fis the frequency of the wave = 4 Hz
The result will be expressed in seconds, so let's multiply by 1000 to get miliseconds:
1 / 4 Hz * 1000 = 250 ms.