Geoffrey Barton

British audio engineer and inventor (b. October 1953), best known for collaborating with Michael Gerzon (1945—1996) on "Ambisonics" surround sound technology. Geoffrey Barton designed hardware for downmixing multitrack studio masters to UHJ Ambisonic in the '80s and collaborated with Gerzon on a custom "2,2,3"-decoder to reproduce conventional two-channel stereo via three Left/Center/Right speakers. He established Trifield Productions Ltd company in 1992 (later "Trifield Audio Ltd") and patented the technology. A few companies that licensed and implemented "Trifield" include Meridian Audio, with native UHJ Ambisonic and Trifield 3D support in AV processors and Jaguar Land Rover car audio systems, and German vendor AGM Digital that supplies professional software and hardware encoders. In the early 1980s, Geoff Barton worked for Audio & Design (Recording) Ltd in Reading, Berkshire, a company that manufactured professional studio equipment. Together with Michael Gerzon, he designed a hardware system to "Ambisonically" mix conventional multitrack stereo recordings. Before that, the only way to produce a UHJ Ambisonic album was by capturing the sound source with a Soundfield microphone (SFM) array (invented by Gerzon's team and Dr. Jonathan Halliday at Nimbus Records). The "Ambisonic Mastering System" consisted of four outboard rack-mounted units and streamlined the production of Ambisonic records. Barton and Gerzon presented the system in May 1984 at the Audio Engineering Society's 2nd International Conference in Anaheim, California. The idea behind Barton's best-known invention, using a central loudspeaker to enhance the soundstage, is about as old as the stereo reproduction itself, leading to the early 1930s experiments by Bell Laboratories in New Jersey and Alan Blumlein's group at EMI in London. Paul Klipsch revived the concept in the late 1950s, solidifying the fundamental "2, 2, 3" configuration: two recording channels, two transmission channels, and three loudspeakers. These early attempts, however — which Gerzon promptly mentioned in his "Optimal Reproduction Matrices for Multispeaker Stereo" paper in October 1991 — designed the center channel by merely "bridging" Left/Right, with only volume-based attenuation. Instead, Michael proposed "frequency-dependent matrix coefficients" that established relations between vector sums of the loudspeaker signals and the squares of those signals, achieving a significant improvement in sound quality and performance. Geoffrey Barton assisted Gerzon in developing the next generation of Ambisonic decoders optimized for HDTV, which they presented in March 1992 at the 92nd AES Convention in Vienna, Austria. The improved design provided an enhanced and more stable frontal sound image and more realistic alignment with on-screen movement. Barton had just established Trifield Productions Ltd at that point, crediting Gerzon as its "Technical Consultant" in the conference paper. Michael has already made several unsuccessful attempts to commercialize Ambisonics technology before. His original research in the 1970s began under the National Research Development Corporation (NRDC), which held all the patents and had very sluggish, bureaucracy-ridden management. Back in 1979, for instance, when Gerzon's team demonstrated the Ambisonics prototype to Dolby Laboratories, Inc., NRDC refused to sell intellectual property rights. Barton's initial attempt to acquire the entire stack of Ambisonics patents from NRDC's successor, British Technology Group, failed. However, they managed to spin off at least the 2,2,3-decoder design, rebranding it as "Trifield." Geoff Barton's '98 patent "Surround sound apparatus" was filed after Gerzon's death but listed him as co-inventor.