What Are Omnidirectional Microphones?

Omnidirectional microphones have a polar plot which is circular, because it records sound from all directions, 0º to 360º, with equal gain. The polar plot image shown is a typical polar plot response of an omnidirectional microphone. You can see the circular pattern. So whether a user speaks into the microphone from any direction or angle, the same gain will be achieved.

Omnidirectional microphones are advantageous over undirectional microphones in that they allow greater flexibility in the directionality of sound pick-up. Stated again, a user can speak into any side of the microphone and it will still pick up good gain from all sides. This can be very useful in applications where sound needs to be recorded from multiple directions. An example of this may be a musical performance where there is a band of musical instruments in front and a choir singing behind. A undirectional microphone would only be able to pick up one of the two with good gain while recording the other very lowly, if at all.