The Decca Tree is a spaced microphone

Microphone

A microphone is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal. In 1877, Emile Berliner invented the first microphone used as a telephone voice transmitter...

 array most commonly used for orchestral recording.

It was originally developed as a sort of stereo

STEREO

STEREO is a solar observation mission. Two nearly identical spacecraft were launched into orbits that cause them to respectively pull farther ahead of and fall gradually behind the Earth...

  A–B recording method adding a center fill. It is the most commonly used spaced-pair technique. The technique was developed in the early 1950s and first commercially used in 1954 by Arthur Haddy, Roy Wallace, Kenneth Wilkinson

Kenneth Wilkinson

Kenneth Ernest Wilkinson was an audio engineer for Decca Records, known for engineering classical recordings with superb sound quality....

, Stan Goodall, and their team at Decca Records

Decca Records

Decca Records began as a British record label established in 1929 by Edward Lewis. Its U.S. label was established in late 1934; however, owing to World War II, the link with the British company was broken for several decades....

, to provide a strong stereo image.

Setup

A Decca Tree setup includes 3 omnidirectional microphones in an upside down "T" pattern. The left and a right mics are placed about 6 feet apart, and the third is placed 3 feet out and centered in front. To mix, the side mics are panned hard left and right, and the output of the middle mic is then sent to both left and right channels.

The Decca Tree was originally used in orchestral situations, fitted on a tall boom and suspended high up in the air, roughly above the conductor. Three separate stands were sometimes used to set individual heights.

Microphones

The technique traditionally uses three omnidirectional microphone

Microphone

A microphone is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal. In 1877, Emile Berliner invented the first microphone used as a telephone voice transmitter...

s, traditionally of the Neumann M-50 small-diaphragm pressure transducer tube

Vacuum tube

In electronics, a vacuum tube, electron tube , or thermionic valve , reduced to simply "tube" or "valve" in everyday parlance, is a device that relies on the flow of electric current through a vacuum...

 condenser type, to record in stereo. These microphones are not truly omnidirectional at the higher frequences, 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

Blumlein Pair

Blumlein Pair is the name for a stereo recording technique invented by Alan Blumlein for the creation of recordings that, upon replaying through headphones or loudspeakers, recreate the spatial characteristics of the recorded signal....

 positioning, in place of the center microphone. The Schoeps M 201 and Neumann KM 56 were also used by the Decca team.

Applications

The Decca Tree is a great sounding stereo miking technique often used in large orchestral or choir performances, but it can also be used as a room miking technique for recordings. When used for room miking 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

Surround sound

Surround sound encompasses a range of techniques such as for enriching the sound reproduction quality of an audio source with audio channels reproduced via additional, discrete speakers. Surround sound is characterized by a listener location or sweet spot where the audio effects work best, and...

 recording. He utilizes a SoundField

Soundfield microphone

The Soundfield microphone is an audio microphone composed of four closely spaced subcardioid or cardioid microphone capsules arranged in a tetrahedron. It was invented by Michael Gerzon and Peter Craven, and is a part of, but not exclusive to, Ambisonics, a surround sound technology...

 MK-V for the center, a pair of Schoeps

Schoeps

Schalltechnik Dr.-Ing. Schoeps GmbH, known as Schoeps, is a German manufacturer of professional studio condenser microphones for recording and broadcast. The privately-owned company is based in Karlsruhe, south-west Germany, and was founded in 1948....

MK21 sub-cardioid condensers for the left and right, and a pair of Schoeps MK41 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.

External links

• Decca Tree Recording with Georg Neumann pressure microphones M 50 - in German — pdf
• Pictures of Decca Tree used in a session at Abbey Road Studios
• The Decca Tree — A classic microphone placement system of the 1950s
• The Decca Tree — It's not just for stereo any more — pdf
• A Decca Tree primer — Wes Dooley, Audio Engineering Associates AEA — pdf
• Stereo Bars and Decca Trees — Wes Dooley, Audio Engineering Associates AEA — pdf
• WikiRecording's Guide to Decca Tree Use and Setup