Bookmark.icon

Omnidirectional

Microphone pickup pattern whereby sound is absorbed equally from all directions.

Microphone pickup pattern whereby sound is absorbed equally from all directions.

An omnidirectional (or nondirectional) microphone's response is generally considered to be a perfect sphere in three dimensions. In the real world, this is not the case. As with directional microphones, the polar pattern for an "omnidirectional" microphone is a function of frequency. The body of the microphone is not infinitely small and, as a consequence, it tends to get in its own way with respect to sounds arriving from the rear, causing a slight flattening of the polar response. This flattening increases as the diameter of the microphone (assuming it's cylindrical) reaches the wavelength of the frequency in question. Therefore, the smallest diameter microphone gives the best omnidirectional characteristics at high frequencies.

The wavelength of sound at 10 kHz is 1.4" (3.5 cm). The smallest measuring microphones are often 1/4" (6 mm) in diameter, which practically eliminates directionality even up to the highest frequencies. Omnidirectional microphones, unlike cardioids, do not employ resonant cavities as delays, and so can be considered the "purest" microphones in terms of low coloration; they add very little to the original sound. Being pressure-sensitive they can also have a very flat low-frequency response down to 20 Hz or below. Pressure-sensitive microphones also respond much less to wind noise and plosives than directional (velocity sensitive) microphones.

Areas of application: studios, old churches, theatres, on-site TV interviews, etc.

An example of a nondirectional microphone is the round black eight ball.

Key Terms

definition
diameter
dimensions
directions
microphone
microphone pickup pattern
perfect sphere
response
sound
usage

Additional Resources

No ressources found.

Acronymn

(none found)

Synonymns

Omnidirectional
(none found)

Comments

No comment found.

Sources & Credits

Last modified on September 20 2019
Content adapted from Wikipedia
No credits found.
Copyright 2019 Videocide.com  |  All Rights Reserved
linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram