Audio and Sound Control: Microphones
Audio is important, audio not only conveys information but adds aesthetic energy and structure to video.
How do microphones hear?
Microphones convert sound waves into electrical audio signals.
Microphones are categorized in three different ways, how well they hear, how they are made and how they are used.
Microphones hear sound in different ways.
Pickup Pattern – the zone within which a microphone can hear well.
Most microphones used in video production are either omnidirectional or unidirectional.
Omnidirectional – Mic hears well from all directions.
Unidirectional – Hears well from one direction, the front.
The most common unidirectional pattern is a cardioid microphone pattern. Cardioid pattern mics capture sound in the shape of a small heart-shaped circle in front of the mic.
There are two additional types of cardioid pickup patterns that are common in video production: supercardioid and hypercardioid. These polar patterns are commonly used in shotgun mics.
Microphones are made in different ways.
A Dynamic Mic – Rugged, can withstand rough handling.
A Condenser Mic – More sensitive, needs power/phantom power.
Ribbon – high quality, very sensitive, not used in film production that much.
How mics are used.
Lavalier microphones: Usually omnidirectional, small, rugged, high quality sound, and usually clipped to clothing.
Hand microphones: Unidirectional, handled by talent/performers.
Boom microphone( shotgun mic) : Kept out of the picture. Because it’s further away from talent, usually a hypercardioid or supercardioid mic is used.
Audio Tools
An audio mixer – Amplifies weak signals, and mix two or more sources.
XLR- Cable for professional microphones and camcorders.
