Stereo systems feature two playback channels – Left and Right. Each channel will have different signals. A microphone array is a collection of microphones that perform together as a unit in order to record the physical width of a sound source, and render it as having a width between the loudspeakers or headphones(Corbett, 2015). Stereo microphone arrays consist of two or more microphones in an organized arrangement. They are designed to record audio in such a way that upon playback a certain sense of the spatial relationships of the sound sources that are present during the recorded performance is reproduced(Moylan, 2012).
Types of stereo microphone techniques:
Spaced pair(AB) technique:
In spaced pair, two microphones face directly in a forward direction and are positioned with their capsules 40 to 60 cm apart. Omnidirectional microphones are generally used for spaced pair technique but there are many applications such as the drum overheads when spaced directional microphones can be used(Corbett, 2015).
X/Y coincident pair technique:
It uses two cardioid or hyper-cardioid microphones positioned so their capsules are as close to each other as possible. The microphones are arrayed between 90 degrees and 130 degrees, with their pickup patterns crossing in front of the array. The midpoint between the two microphones is pointed towards the source, and the microphone outputs are panned equally to left and right(Huber & Runstein, 2014).
X/Y coincident pair technique
M-S or mid-side microphone technique:
It offers superior imaging by using microphones arranged in an upside-down “T” pattern. The mid microphone which is often a cardioid or hyper-cardioid but sometimes can be an omnidirectional microphone, is aimed at the sound source, and the side microphone usually a bi-directional microphone is placed parallel to the sound source and at a 90 degree angle to the mid microphone to pick up the sound to the left and right(Reese, Gross & Gross, 2009).
M-S microphone technique
Blumlein pair technique:
In this technique, the stereo microphone pattern controls are both set to bi-directional or figure-8 microphone, and the capsules are oriented at an angle of 90 degrees to each other(Kefauver, 2001).
Blumlein pair technique
Corbett, I. (2015). Mic it!. Burlington: Focal Press.
Huber, D., & Runstein, R. (2014). Modern recording techniques (8th ed.). Abingdon: Focal Press.
Kefauver, A. (2001). The audio recording handbook. Middleton, Wis.: A-R Editions.
Moylan, W. (2012). The Art of Recording. Hoboken: Taylor and Francis.
Reese, D., Gross, L., & Gross, B. (2009). Audio production worktext. Amsterdam: Elsevier.