The polar pattern of a microphone is the sensitivity to sound relative to the direction or angle from which the sound arrives, or easier worded how well the microphone “hears“ sound from different directions. The most common types of directionality are: Omnidirectional, Cardioid and Supercardioid
A cardioid microphone has the most sensitivity at the front and is least sensitive at the back. It isolates from unwanted ambient sound and is much more resistant to feedback than omnidirectional microphones. That makes a cardioid microphone particularly suitable for loud stages.
Supercardioid microphones offer a narrower pickup than cardioids and a greater rejection of ambient sound. But they also have some pickup directly at the rear. Hence it is important to place monitor speakers correctly. Supercardioids are most suitable when single sound sources need to be picked up in loud environments. They are the most resistant to feedback.
The omnidirectional microphone has equal output or sensitivity at all angles, this means it picks up sound from all directions. Therefore the microphone has not to be aimed in a certain direction which is helpful especially with lavalier microphones. A disadvantage is that an omni cannot be aimed away from undesired sources such as PA speakers which may cause feedback.
A microphone with a figure of eight polar pattern picks up the sound from in front of the microphone and from the rear but not the side (90 degree angle). Microphones with this Figure of Eight polar pattern are typically ribbon or Large Diaphragm Microphones.
|Figure of Eight|
|INFO: Proximity Effect|
|Every directional microphone (i.e. cardioid, supercardioid) has a so-called proximity effect. This is created when the microphone moves closer to the sound source resulting in an increase in bass response and, hence, warmer sound. Professional singers often work with this effect. To test this out, experiment with bringing the microphone closer to your lips when singing and listen for the change in sound.|