Both condenser and dynamic microphones can be engineered to be sensitive to sound in different ways or patterns, by creating areas the microphone will both pickup and reject sound. This is called the microphones polar pattern. We will look at three different patterns.
Cardioid
Microphones with Cardioid polar patterns have been engineered to pick up sound from in front of the mic capsule, be less sensitive to sound from the side and reject sound as much as possible from behind. This polar pattern makes for a good vocal microphone. Cardioid microphones are prone to an effect called Proximity Effect. This refers to the base tones being exaggerated as the source of sound moves closer to the microphone. It’s a good idea to keep about 6 inches from your microphone when talking.
Omnidirectional
Omnidirectional microphones can pick up sound from all around. They are equally sensitive in all directions. They don’t really suffer from the proximity effect. Omnidirectional characteristics are useful in lavalier microphones. When the wearer moves their head, the tone doesn’t change that much.
Supercardioid
Supercardioid microphones have a much more focused polar pattern to pick up sound from in front of the microphone and reject sound to the sides. You will be able to pick up sound from further away when the microphone is placed to point directly at the source of sound. These microphones are longer in shape and are referred to as shotgun microphones. Because of it’s characteristics, it is this type of microphone that will be used as a boom microphone by filmmakers. Supercardioid microphones will also display the proximity effect.