Microphone Polar Pattern
There are two basic types of microphone — omnidirectional and unidirectional.
Omnidirectional mic. It is sensitive to sounds from all directions.
Best to use when more room ambiance is the goal. Direct and ambient sound can be adjusted by moving the mic closer to or further from the sound source.
These are sensitive to sound coming from only one direction – let’s say from a guitar amplifier.
The most common type of unidirectional microphone is called a “cardioid” because its pickup pattern is heart-shaped. It picks up most sound from the front of the microphone and some from the sides.
Supercardioid / Hypercardioid
Supercardioid or hypercardioid microphones offer even greater sound isolation through narrower pickup patterns.