During the early 1970′s, and while the battle between SQ, QS & CD-4 was underway (and long before CBS’s ‘Ghent Microphone), a small British company called Calrec were devoloping what was to become known as the Soundfield microphone. This, along with other design developments, was the start of Ambisonics. The name now given to this early system is 45j.
Only one LP using this system was know to have been released (by Calrec themselves in 1974), but as there were no commercial decoders available, few copies were sold and to this day, only one copy is known to exist. Not even Calrec themselves have a copy, or knowledge of its existence.
Unfortunately this ground breaking work went largely un-noticed until late 1978 when the BBC & Denon merged their knowledge with their various quadraphonic systems with the developers of 45j, and under the auspice of the N.R.D.C. (National Research Development Council) developed UHJ.