One essential aspect is what direction a microphone hears. To understand this, you must understand a little about polar patterns, because they are essential to picking the right microphone. Polar patterns are easiest described when 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 to 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 hear and what it can't. In the case of the cardioid microphone, you can see that it hears best 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. By looking at polar patterns, you can tell the direction and scope of what the microphone will hear and what it won't. Out of the five polar patterns you see 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

As we said, a cardioid microphone hears sounds in front of it best. The subtypes, hypercardioid and supercardioid, simply change how much it can hear behind. If you look at FIGURE 9-1, you will see that both hypercardioid and supercardioid have very little shaded areas behind them. 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 use this microphone pointed right at your sound source, you won't experience much bleed from other instruments in other directions.

An omnidirectional microphone hears 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 great for recording two vocalists on one microphone, or for recording between two instruments, blocking out the sides.