A Brief Summary And Description Of Microphones

Submitted By Paulthollywood11
Words: 2234
Pages: 9

GLOSSARY:

A-B: A stereo microphone array consisting of a spaced pair of omnis. Normal spacing does not exceed about 1.5 meters (5 feet).
Bidirectional : A microphone pickup pattern that is maximum at zero and 1800s, and minimum at plus and minus 900. So called for the resemblance of the polar plot to the figure eight. (see attached summary of first-order cardioid microphones)
Cardioid: A microphone pickup pattern that is maximum at 00, 6 dB down at plus and minus 900, and effectively zero at 1800. So called for the resemblance of the polar plot to a heart shape. (see attached summary of first-order cardioid microphones)
Condenser (Capacitor) Microphone: A microphone that operates on the principle of a variable condenser or capacitor. The sound receptor is one plate of a capacitor that moves in sync with impinging sound waves; the resulting change in capacitance modulates an applied voltage on the capacitor.
Dynamic Microphone: A microphone that operates on the principle of voltage induction by a moving coil of wire in a magnetic field. The coil is attached to a light diaphragm that moves in sync with impinging sound waves.
Hypercardioid: A microphone pickup pattern with high forward directivity. Response at plus and minus 900 is -12 dB, relative to on-axis. There is a minor lobe at 1800 that is -6 dB relative to on-axis. (see attached summary of first-order cardioid microphones)
Image Specificity: The quality in a stereo recording that emphasizes precise positioning of a source on the stereo soundstage.
Image Spatiality: The quality in a stereo recording that emphasizes the acoustical space in which that recording was made.
Off-Axis Coloration: A characteristic of many directional microphones to exhibit erratic frequency response at angles other than the principal axis.
Omnidirectional: A microphone pickup pattern that is essentially equal in all directions. As a practical matter, most omni microphones will exhibit a preference along the principal axis at very high frequencies. (see attached summary of first-order cardioid microphones)
ORTF: Stands for Office of Radio-Television Française, the French national broadcasting company. Refers to a near coincident stereo microphone pickup using two cardioids spaced by 17 cm and splayed at an angle of 1100.
Panning: Refers to the postproduction technique of mixing a signal in relative degrees between two stereo channels, causing the perceived stereo image position to be located at a specific point between the channels.
Polar Patterns: Refers to the typical measurement of microphone directivity in which microphone directional response is plotted with respect to bearing angle. (see attached summary of first-order cardioid microphones)
Presence Peak: Refers to the intentional increase in microphone sensitivity in the 2 to 4 kHz frequency range, useful for adding presence to vocal pickup.
Proximity Effect: Refers to the increase in low frequency response when directional microphones are used at short working distances. Caused by the pressure gradient at low frequencies between the primary and secondary openings to the microphone.
Stereo Soundstage: The virtual soundstage reproduced between a pair of loudspeakers by a two-channel stereo program source. Soundstage accuracy implies a continuum of images (reproduced sources) from left to right.
Supercardioid: A microphone pickup pattern that is mid-way between a cardioid and a hypercardioid. Response at plus and minus 900 is -8.6 dB relative to on-axis. Response at 1800 is -11.7 dB relative to on-axis. (see attached summary of first order cardioid microphones)
Timbre: Refers to the sound quality of an instrument or other source of sound. From the French word meaning "stamp," or characteristic.
X-Y: Refers to any stereo pickup arrangement using a pair of directional microphones that are as closely spaced as possible.



SOME SOUND JOB DESCRIPTIONS
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