Phase 4 Stereo was a recording process created by the U.K. Decca Records label in 1961.[1] The process was used on U.K. Decca recordings and also those of its American subsidiary London Records during the 1960s.
Phase 4 Stereo recordings were created with an innovative 10-channel, and later 20-channel, "recording console".[2]
The 10-channel and 20-channel console outputs for Phase 4 recordings were originally made on then novel 4-track tape, but the innovation was in the special scoring used to maximize the technology. In recording techniques of the early-to-mid-60s, to get the kind of layered sound realized in Phase 4 recordings, multiple overdubs over multiple reels of tape, bouncing down and bouncing across to different recorders were used. This increased the level of tape hiss on the final master, something which Phase 4 engineers wanted to avoid. They achieved in their scoring techniques in one pass what everybody else was achieving with multiple overdubs.
Approximately two hundred albums were released with the process, including popular music, "gimmick" records engineered to make the sound travel from speaker to speaker, records featuring percussion effects, and historical sound effect records. In 1964, a light classical Phase 4 "Concert Series" was produced. The label was a major financial success for Decca.[3]
- ^ "London Phase 4 Stereo Line Premieres at Meet". Billboard Music Week. 14 August 1961. p. 2. Retrieved 29 December 2024.
- ^ "Endless Groove – London Phase 4 Stereo". Endlessgroove.com. Archived from the original on 28 January 2015. Retrieved 20 August 2015.
- ^ Patmore, David. The Phase 4 Story. Classical Recordings Quarterly, Winter 2014, No.79, p.42-46.