705 Hz Wavelength

How Long Is a 705 Hz Wavelength?

A 705 Hz sound wave has a wavelength of 0.49 meters, 48.68 cm, 1.6 feet (1 feet and 7.17 inches) or 19.17 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 = 705 Hz
which gives a wavelength λ of 0.49 meters, or 1.6 feet.

705 Hz Wavelength Depending on Temperature

The speed of sound in air depends on temperature. Here is how the wavelenght of a 705 Hz sound wave will vary according to temperature:

Temp (°C) Temp (°F) 705 Hz wavelength (cm)705 Hz wavelength (in)
-40-4043.416017.0929
-35-3143.879017.2752
-30-2244.337317.4556
-25-1344.790817.6342
-20-445.239817.8109
-15545.684417.9860
-101446.124718.1593
-52346.560818.3310
03246.992918.5011
54147.421118.6697
105047.845418.8368
155948.266019.0024
206848.682919.1665
257749.096319.3293
308649.506319.4907
359549.912919.6507
4010450.316219.8095

705 Hz Half Wavelength and Standing Waves

The half wavelength of a 705 Hz sound wave is 0.24 meters, 24.34 cm, 0.8 feet (0 feet and 9.58 inches) or 9.58 inches when travelling in air at 20°C (68°F).

Modes (or standing waves) will occur at 705 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 705 Hz wavelength = 0.49 meters, or 1.6 feet in air at 20°C (68°F).

705 Hz Standing Waves Distances

n Distance (m) Distance (ft)
10.240.80
20.491.60
30.732.40
40.973.19
51.223.99

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

Given the relatively small 705 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 705 Hz To ms

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

Because a 705 Hz wave will ocillate 705 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 = 705 Hz

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

1 / 705 Hz * 1000 = 1.42 ms.