Decca tree
The Decca Tree is a spaced microphone array most commonly used for orchestral recording. It was originally developed as a type of stereo A–B recording method adding a center fill. The technique was developed in the early 1950s and first commercially used in 1954 by Arthur Haddy, Roy Wallace, and later refined by engineer Kenneth Ernest Wilkinson and his team at Decca Records and its recording studios,[1] to provide a strong stereo image.
The Decca Tree setup evolved from the idea of a minimal recording technique using a pair of microphones. The first system was developed by Roy Wallace. The microphone triangle was placed about 3 to 3.6 m high above the stage level, near the conductor. The microphone system is not properly in front of the orchestra, but more "into" the orchestra.
Two more microphones can be added and placed on the sides (called "outrigger microphones"), approximately at about 2/3 of the stage width, between the conductor and the outer orchestra boundary.
Microphones[edit]
The technique traditionally uses three omnidirectional microphones, traditionally of the Neumann M 50 small-diaphragm pressure transducer tube condenser type, to record in stereo. These microphones are not truly omnidirectional at the higher frequencies, but exhibit some high frequency lift and directionality which is likely to positively affect stereo imaging of the Decca Tree arrangement. Variations have been performed using a coincident pair, in X-Y, Mid/Side (M/S), or Blumlein positioning, in place of the center microphone. The Neumann M 49, KM 53, and KM 56 were also evaluated and used for early sessions by the Decca team, and later the Schoeps MK 2S were used by the team for live productions where the M 50 proved too cumbersome.[1][3]
Applications[edit]
The Decca Tree is a stereo miking technique often used in large orchestral or choir performances, but it can also be used as a room miking technique. When used for room miking of drums, its wide stereo image captures the nuances of bigger environments better than most other techniques. In smaller rooms however, the Decca Tree does not work as well.
Ron Streicher, author of The Decca Tree — It's not just for stereo any more, has also described methods for employing a Decca Tree for surround recording. He utilizes a SoundField MK-V for the center, a pair of Schoeps MK 21 sub-cardioid condensers for the left and right, and a pair of Schoeps MK 41 hypercardioid condensers for the left and right surrounds. The MK-V affords a number of possibilities to the Decca Tree, as it is a four-element transducer that can be decoded into 5.1 and 7.1 sound fields on its own, using the SoundField SP451.