How Long Is a 693 Hz Wavelength?
A 693 Hz sound wave has a wavelength of 0.5 meters, 49.53 cm, 1.62 feet (1 feet and 7.5 inches) or 19.5 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 = 693 Hz
λ
of 0.5 meters, or 1.62 feet.
693 Hz Wavelength Depending on Temperature
The speed of sound in air depends on temperature. Here is how the wavelenght of a 693 Hz sound wave will vary according to temperature:
Temp (°C) | Temp (°F) | 693 Hz wavelength (cm) | 693 Hz wavelength (in) |
---|---|---|---|
-40 | -40 | 44.1678 | 17.3889 |
-35 | -31 | 44.6388 | 17.5743 |
-30 | -22 | 45.1050 | 17.7579 |
-25 | -13 | 45.5664 | 17.9395 |
-20 | -4 | 46.0232 | 18.1194 |
-15 | 5 | 46.4755 | 18.2974 |
-10 | 14 | 46.9234 | 18.4738 |
-5 | 23 | 47.3671 | 18.6485 |
0 | 32 | 47.8066 | 18.8215 |
5 | 41 | 48.2422 | 18.9930 |
10 | 50 | 48.6739 | 19.1629 |
15 | 59 | 49.1017 | 19.3314 |
20 | 68 | 49.5259 | 19.4984 |
25 | 77 | 49.9465 | 19.6640 |
30 | 86 | 50.3636 | 19.8282 |
35 | 95 | 50.7772 | 19.9910 |
40 | 104 | 51.1875 | 20.1526 |
693 Hz Half Wavelength and Standing Waves
The half wavelength of a 693 Hz sound wave is 0.25 meters, 24.76 cm, 0.81 feet (0 feet and 9.75 inches) or 9.75 inches when travelling in air at 20°C (68°F).
Modes (or standing waves) will occur at 693 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 693 Hz wavelength = 0.5 meters, or 1.62 feet in air at 20°C (68°F).
693 Hz Standing Waves Distances
n | Distance (m) | Distance (ft) |
---|---|---|
1 | 0.25 | 0.81 |
2 | 0.50 | 1.62 |
3 | 0.74 | 2.44 |
4 | 0.99 | 3.25 |
5 | 1.24 | 4.06 |
We typically don't treat rooms for standing waves above 300 Hz.
Given the relatively small 693 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 693 Hz To ms
A Hz (Hertz) is a cycle (or period) per second.
Because a 693 Hz wave will ocillate 693 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 = 693 Hz
The result will be expressed in seconds, so let's multiply by 1000 to get miliseconds:
1 / 693 Hz * 1000
= 1.44 ms.