(term) Cardioid

The most common unidirectional microphone is a cardioid microphone, so named because the sensitivity pattern is heart-shaped. A hyper-cardioid microphone is similar but with a tighter area of front sensitivity and a smaller lobe of rear sensitivity. A super-cardioid microphone is similar to a hyper-cardioid, except there is more front pickup and less rear pickup. These three patterns are commonly used as vocal or speech microphones, since they are good at rejecting sounds from other directions.

A cardioid microphone is effectively a superposition of an omnidirectional and a figure-8 microphone; for sound waves coming from the back, the negative signal from the figure-8 cancels the positive signal from the omnidirectional element, whereas for sound waves coming from the front, the two add to each other. A hypercardioid microphone is similar, but with a slightly larger figure-8 contribution. Since pressure gradient transducer microphones are directional, putting them very close to the sound source (at distances of a few centimeters) results in a bass boost. This is known as the proximity effect.



Mar 20, 2000
Nanaimo BC, Canada
A microphones pickup characteristic, notably strong sensitivity to material presented to the front of the microphone, while sensitivity falls off from sources arriving at an angle of 90° or greater away from the front, and good rejection from the rear. The name derives from a representation of the polar pattern, which loosely resembles a heart shape. Prone to exhibit pronounced proximity effect, where bass frequencies are accentuated the closer the source to the microphone.
(See Hypercardioid)