The Polar Pattern of a microphone determines how the microphone perceives sound 360 degrees around the capsule and ultimately helps engineers decide on a microphone’s use and application. Some microphones have multiple polar patterns while others are designed for one specific pattern. Understanding the sound of any microphone is very important, especially when harnessing that knowledge on a session that has a multi-mic’d instrument.
How to read these patterns
These graphs are read from the top down. 0 degrees is the front of the microphone and 180 degrees is the back of the microphone. The graph displays angle over the decibel level.
Cardioid microphones reject the most when the microphone’s back is facing a sound source, that’s why the pattern curves into the center of the diagram showing more than -25dB of rejection. In contrast, the front of the microphone is ideal spot (obviously) for the sound source. As the sound moves to either 90 degrees or 270 degree it gradually reduces in volume.
This type of microphone can be used in various formats and can be especially useful in environments where sound rejection is key like small practice spaces and rooms with walls made of drywall.
Bidirectional (also called Figure 8) microphones capture sound equally from both the front and back of the microphone. The most rejection happens at 270 degree and 90 degree angles where the microphone captures less than -25dB. Some specific techniques using Bidirectional microphones include Mid-Side configurations like the one outlined in this article where the Bidirectional microphone is used to pick up the ambient sounds from a 90 degree angle. I’ve also used this configuration on Snare Bottom to reduce bleed from the sound of the beater hitting the kick drum.
Hypercardioid and Supercardioid
Hypercardioid is more or less a the same as a Bidirectional pattern except that it has more rejection from the back of the microphone – making the front more sensitive. Supercardioid is effectively even more directional in that it rejects more sound from the back of the mic. These microphones are great for live use because of their frontward sensitivity and extreme rejection from the back. This helps live engineers reduce feedback and other issues during a show.
Omnidirectional microphones pick up sound from 360 degrees around the capsule. They are a great choice for group vocals, gang vocals, and room microphones. It’s easy to use them in environments where it is the only microphone needed like a conference room or listen-microphone in a studio live room. Creative applications for these microphones can include a mono-drumkit setup where the microphone is placed in front of the kick aimed upward at the snare. For the most part these are not ideal for live applications where there is bleed from other instruments.
The shotgun polar pattern has tons of frontward sensitivity at long distances. Onset dialogue for Video, TV, and Film is typically recorded with shotgun microphones because of the extreme distances used. This is to ensure that the microphone does not dip into any shot. Some manufacturers now have mountable shotgun microphones for both iPhone and DSLR cameras – completely eliminating the need for handheld microphones during interviews.
Check out more Microphone Tips on The Cakewalk Blog: