Editing Quadraphonic sound (section)

==Radio broadcast formats==

There were some experiments done with [[radio]] broadcasts (e.g., a [[Cliff Richard]] concert by the [[BBC]],<ref name="genome1">{{cite web|url=http://genome.ch.bbc.co.uk/863cca179e104e9eaacb3f7ad6628fe0|title=Cliff Richard|work=BBC Genome at [[BBC Online]]|date=24 March 1978 |access-date=18 November 2014}}</ref><ref name="genome2">{{cite web|url=http://genome.ch.bbc.co.uk/9383f9bb4cc342248d91c45767b16b42|title=Cliff Richard|work=BBC Genome at [[BBC Online]]|date=2 January 1978 |access-date=18 November 2014}}</ref> whose earliest quadraphonic broadcast was in July 1974<ref name="genome3">{{cite web|url=http://genome.ch.bbc.co.uk/5c91d7ea06f6456092a8f9f158bb044d|title=BBC in quad|work=BBC Genome at [[BBC Online]]|date=5 July 1974 |access-date=18 November 2014}}</ref>), but they were short-lived.

One of the longest-lived radio broadcasts was [[WHPT|WQSR]]-FM "Quad 102½" in [[Sarasota, Florida]].<ref>{{Cite web|url=http://www.radioyears.com/other/details.cfm?id=864|title=Radio Years.com|website=www.radioyears.com}}</ref> Throughout most of the 1970s this station broadcast a signal which could be tuned as two separate stations with conventional stereo receivers.

[[San Francisco]] classical music station [[KGMZ-FM|KKHI-FM]] broadcast the [[San Francisco Opera]] in "compatible" (that is, matrix-encoded) quadraphonic format during the 1970s,<ref>{{cite news|work=Napa Valley Register|title="Opera Concertante" at Mondavi's|first=Bernice|last=Dunn|url=https://www.newspapers.com/clip/59243547/|page=7D|date=March 17, 1973|access-date=September 13, 2020}}</ref> as did [[Chicago]] station [[WFMT]]'s live "Chicago Lyric Opera" broadcasts.

[[KRMH]]-FM ("Good Karma Radio")(San Marcos/Austin, Texas) broadcast in "Quad Stereo" in the early 1970s from its studios and transmitter near [[Buda, Texas]].<ref>{{Cite book|url=https://books.google.com/books?id=8hkiDAAAQBAJ&dq=KRMH-FM+Quad+Stereo+-wiki&pg=PT202|title=Sweet Dreams and Flying Machines: The Life and Music of James Taylor|first=Mark|last=Ribowsky|date=June 1, 2016|publisher=Chicago Review Press|isbn=9781613733790 |via=Google Books}}</ref>

[[WLLZ (FM)|WWWW-FM]] (W4-QUAD 106.7) (Detroit) broadcast QS encoded quadraphonic sound in 1974.<ref>{{Cite magazine |date=November 9, 1974 |title=Live 'Q' Airings Set for N.Y.'s Newest FM Rocker |pages=24 |magazine=Billboard |url=https://books.google.com/books?id=rQcEAAAAMBAJ&dq=%22WWWW-FM%22+quad&pg=PA6}}</ref>

[[KEXL]]-FM ("KEXL 104.5") (San Antonio, Texas) broadcast in "Quadraphonic" in the early to mid 1970s from its studios in a high-rise office building off Main Plaza.<ref>{{cite web|url=http://www.penningtontechnicalarts.com/KEXL/|title=KEXL 104.5|url-status=dead|archive-url=https://web.archive.org/web/20161013093340/http://www.penningtontechnicalarts.com/KEXL/|archive-date=October 13, 2016}}</ref>

Seattle station KIRO-FM 100.7 later branded as KSEA 101 broadcast several hours daily between 1973 and early 1976 encoded SQ quadraphonic music.<ref name="auto">{{Cite magazine |last=Hall |first=Claude |date=July 31, 1971 |title=Vox Jox |pages=30 |magazine=Billboard |url=https://books.google.com/books?id=uggEAAAAMBAJ&dq=KIRO-FM+++quad&pg=PA30}}</ref> Sunday morning's "Music and the Spoken Word" from Salt Lake's Mormon Tabernacle was in SQ quad.<ref name="auto"/>

[[File:Audio & Design's Ambisonic Mastering System.jpg|thumb|Ambisonic mixing equipment]]
''[[Matrix H]]'' was developed by [[BBC]] engineers in 1977 to carry quadraphonic sound via [[FM radio]] in a way which would be most compatible with existing mono and stereo receivers.<ref>{{Cite web |url=http://beophile.com/?page_id=9532 |title=Quadraphonic Sound |access-date=2014-09-21 |archive-url=https://web.archive.org/web/20141211085126/http://beophile.com/?page_id=9532 |archive-date=2014-12-11 |url-status=dead }}</ref>

Quadraphonic test programmes were made for [[BBC Radio 3]] and [[BBC Radio 4]], including plays and [[The Proms]].<ref>{{cite journal |author=Ratcliff, P.A. |author2=Meares, D.J. |title=BBC Matrix H: Compatible system for broadcasting |journal=Wireless World | pages=41–45 |date=May 1977}}</ref>

The existing matrix formats were tested first. The "H" does not stand for a word; they called the first matrix they assessed Matrix A, and then worked through the alphabet.<ref>{{cite journal |author=Crompton, T. W. J. |title=The subjective performance of various quadraphonic matrix systems |journal=BBC Research Department Report 1974/29 | date=November 1974 |url=http://downloads.bbc.co.uk/rd/pubs/reports/1974-29.pdf }}</ref><ref>{{cite journal |author=Gaskell, P. S. |author2=Ratliff, P. A. |title=Quadraphony: Developments in Matrix H decoding |journal=BBC Research Department Report 1977/2 |date=February 1977 |volume=77 |page=22306 |bibcode=1977STIN...7722306G |url=http://downloads.bbc.co.uk/rd/pubs/reports/1977-02.pdf }}</ref> Matrix H emerged as the best solution for mono compatibility and radio transmission,<ref name=autogenerated1>{{Cite web|url=http://midimagic.sgc-hosting.com/quadrafon.htm|title=Quadraphonic Systems|website=midimagic.sgc-hosting.com}}</ref> but there was no specific commercially available decoder for it.

The BBC later cooperated with the developers of [[Ambisonics]] to produce ''BBC/NRDC System HJ''. This was based on tolerance zones designed to include modified versions of both ''Matrix H'' and the prototype two-channel encoding of [[Ambisonics]], known as ''System 45J''. Subsequently, the Nippon-Columbia ''UMX'' matrix was brought into the standard, leading to the final [[Ambisonic UHJ Format|''UHJ'']] name now associated with [[Ambisonics]].<ref>{{cite report |date=22 November 1977 |title=Encoding Standards for NRDC Universal HJ Surround-Sound Encoding System: "System UHJ" |publisher=[[National Research Development Corporation]] |id=NRDC/FCC 2 }}</ref>

=== Universal SQ ===

In 1976, Ben Bauer integrated matrix and discrete systems into ''USQ'', or ''Universal SQ'' (others had also done this with their quad systems).

It was a hierarchical 4–4–4 discrete matrix which used the SQ matrix as the baseband for discrete quadraphonic FM broadcasts using additional difference signals called "T" and "Q".
For a USQ FM broadcast, the additional "T" modulation was placed at 38&nbsp;kHz in quadrature to the standard stereo difference signal and the "Q" modulation was placed on a carrier at 76&nbsp;kHz.

For standard two-channel SQ Matrix broadcasts, CBS recommended that an optional pilot-tone be placed at 19&nbsp;kHz in quadrature to the regular pilot-tone to indicate SQ encoded signals and activate the listener's logic decoder. CBS argued that the SQ system should be selected as the standard for quadraphonic FM because, in FCC listening tests of the various four-channel broadcast proposals, the 4:2:4 SQ system, decoded with a CBS Paramatrix decoder, outperformed 4:3:4 (without logic) as well as all other 4:2:4 (with logic) systems tested, approaching the performance of a discrete master tape within a very slight margin. At the same time, the SQ "fold" to stereo and mono was preferred to the stereo and mono "fold" of 4:4:4, 4:3:4 and all other 4:2:4 encoding systems.