Microphone Polar Patterns
Some microphones can be aimed at a source and focus in on it, while other microphones are designed to pick up sounds from all directions evenly. The direction in which the microphone picks up sound is called its polar pattern.
There are 3 main polar patterns, although it is also possible for a polar pattern to be somewhere in between the 3.
The 3 main polar pickup patterns are omnidirectional, typically just called omni, Cardioid, and Figure 8.
Omnidirectional has the most even frequency response, and picks up all sounds from all directions evenly. Omni tends to be the most natural sounding. The reason omni is not used very often in home studios is because it will pick up the room more, and all the sounds in the room. Other pickup patterns can focus more on the source.
This leads us into the cardioid pickup pattern. It rejects sound from the rear of the microphone, and is most sensitive to sounds directly in front of it. It will also pickup sounds from the sides, but with less volume than from the front.
The figure 8 pickup pattern is the most focused, and picks up sound from the front and rear. It has the best rejection of any pickup pattern, providing excellent rejection from the sides at 90 degrees.
Halfway in between cardioid and figure 8 is super cardioid. This has a more focused area of pickup directly in front of the microphone, with a small amount off pickup directly from the rear. It has its best rejection at 270 degrees from its front axis.
The super cardioid pattern is popular to use in live settings, because it focuses on the sound in front, and rejects sound from the sides, making them less prone to feedback.
Next we’ll talk about proximity effect, because this coincides directly with the polar pattern.
Proximity effect is a boost in low frequencies that happens from being closer to the microphone, and is more prominent as the polar pickup pattern becomes more directionally focused. So, proximity effect will be the greatest with a figure 8 pickup pattern, because figure 8 is the most focused.
The omni pick up pattern has no directional focus, and therefore is not effected by proximity effect.