Polar patterns by Marc Schonbrun

Directionality is an essential aspect of a microphone. To understand this, you must understand a little about polar patterns, because they are critical to picking the right microphone. Polar patterns are best understood by looking at one. Figure 9-1 shows the polar patterns you will encounter when microphone shopping.

Around the outside of the circle are degree markings. These degrees signify the origination of the sound in relation to where the microphone is pointed. Simply, the microphone is pointed at 0 degrees. The shaded areas in the circle show direction and scope of what the microphone can pick up and what it can't. In the case of the cardioid microphone, you can see that it's most sensitive to what's directly in front of it, at 0 degrees. If you were to stand behind a cardioid pattern microphone, at 180 degrees, the microphone would be basically deaf to anything you say. Out of the five polar patterns in this figure, there are only three main polar patterns (cardioid, omnidirectional, and figure-eight), and the remaining two (hypercardioid and supercardioid) are subpatterns.

Figure 9-1: Microphone polar patterns

To repeat, a cardioid microphone is most sensitive to sounds in front of it. The subtypes, hypercardioid and supercardioid, simply change how much it can hear behind. You will see in Figure 9-1 that both hypercardioid and supercardioid have very little shaded areas behind them. This means that you can minimize microphone bleed by close-miking an instrument with a supercardioid microphone, since it rejects sounds from behind it so well. A supercardioid will only hear what's right in front of it. If you point this microphone right at your sound source, you won't experience much bleed from other instruments in other directions.

An omnidirectional microphone picks up everything from all sides. You can see in its polar pattern that the shading is all around the microphone. Omnidirectional microphones are great room microphones and work well with large groups.

A figure-eight microphone hears sounds only directly in front and directly in back of it, rejecting much of the sounds from the sides. Figure-eight microphones are best for recording two vocalists on one microphone, or for recording between two instruments, blocking out the sides.