Understanding Microphone Polar Patterns

Every microphone has something called directionality, which refers to how the microphone picks up sounds. Depending on what you’re filming, you may want a microphone that can pick up sound from one direction, all directions or a combination of directions. These different types of microphones are also useful in specific cases. For example, unidirectional lavalier microphones are great for interviews because the microphone is focused on the speaker’s audio and can reduce background noise that might be distracting to listeners. The three main types of microphones are unidirectional, omnidirectional and bidirectional. Learn more about each to determine which is best for your filming.

The unique polar pattern of a cardioid microphone allows the device to pick up more noise from the front of the mic and less from the back. This helps to focus on the sound coming from one particular direction as the front of the microphone is more sensitive and therefore captures more crisp, clear sound from that direction. The back of the mic is designed to be less sensitive to noise, which helps to eliminate unwanted background sounds. Cardioid microphones feature one of the most popular mic patterns that can be used in many scenarios.

Using omnidirectional microphones will allow you to pick up sounds from all directions which can be useful in some situations but it also can be distracting. These types of microphones are typically used in a situation when the speaker (or speakers) will be moving around the scene a lot without the ability to move the microphone at the same time. These mics are often used when recording music with multiple instruments playing at the same time or live productions with several actors on stage at the same time.

Similar to cardioid microphone patterns, supercardioid devices also pick up sound mainly from the front of the mic, but the area in which it can capture audio is more narrow than a traditional cardioid mic. Although the back of this mic is less sensitive to sound, it can still pick up some noise, making it vital that the microphone is placed in a specific spot in relation to the speaker. Typically, this type of mic is used in situations where there is a single person speaking in an environment with a lot of background noise.

The opposite of an omnidirectional mic, unidirectional microphones capture sound that is emanating from one direction. Many wireless microphones are unidirectional, allowing the device to capture sound from one source and giving the speaker freedom to move around the scene without picking up unwanted background noise. Unidirectional mics can be either cardioids or hyper cardioids which means these devices pick up sound in a heart-shape, eliminating audio coming from the sides of the speaker.

Bidirectional microphones are not used as often as the other two options, but there are some situations in which this type of device could be useful. Bidirectional mics pick up sound in a figure eight-like pattern, meaning audio is captured from opposing sides of the microphone. The most common situation, which requires this type of mic, is an interview with two people facing each other.