Polar Pattern (Cardioid / Omni / Fig-8)
Definition
The polar pattern of a microphone describes its sensitivity according to the direction of the sound. An omnidirectional microphone picks up equally in all directions and, as a pressure microphone, shows no proximity effect. A cardioid pattern is most sensitive at the front and rejects the rear, with its null at 180°. Supercardioid and hypercardioid patterns are narrower at the front and have a small rear lobe; according to Shure, their nulls lie at about 125° and 110° respectively. A figure-8 (bidirectional) microphone picks up front and rear equally, has its nulls at 90° to the sides, and is used in mid-side and Blumlein stereo techniques.
In the field
Because a supercardioid rejects most at about 125° off axis, Shure recommends placing wedges at that angle, on either side of the rear, rather than directly behind the microphone. For a hypercardioid, the corresponding angle is about 110°.
Related lessons
Sources
- Shure, « Specialist Polar Patterns: Hypercardioid and Subcardioid » : annulations à 125° (supercardioïde) et 110° (hypercardioïde), placement des retours · shure.com
- Shure, « Microphone Directionality and Polar Pattern Basics » : omni, cardioïde, figure-8 · shure.com
- Microphone (Wikipedia) : micros à pression sans effet de proximité, figure-8 et stéréo Blumlein · en.wikipedia.org