Sony SQA-2030 Decoder/Rear Channel Amplifier. RM, SQ. 18 watts ch. $240 '74.
Quadraphonic Formats
3-30-1999 VERSION 1.3

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  *        /|\               *     Mark Anderson
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  • Quad 8-track head layout

  • JVC's CD-4 Quadraphonic Compatable Disc Format

  • CD-4 Quadraphonic Equipment

      There were several so called "matrix" systems, where the four 
    channels of quadraphonics were encoded into two channels and decoded 
    back to four.  At least this was the intention.  But the egg theory
    applies:  If you take four chicken eggs and break them in a bowl, you
    can see at the bottom, four yellow rounds and the clear stuff around
    them.  The moment you stick in your fork and mix them, the yellows get
    broken and it becomes VERY difficult to put them back together again. 
    You possibly could portion the yellow stuff in four equal cups, but 
    the other stuff is mixed with the yellow already.  This was the sad 
    state of the early quad matrix decoders.....many of them resembled four-
    channel MONO or at best DOUBLE-STEREO upon decoding/playback.  
    Interchannel separation was 3-10db (worse than the average 25db of a 
    normal stereo recording).  It took years of development to perfect 
    the "Logic"  circuits required to properly decode the matrix , and by
    the time the really good logic decoders came to market, it was around
    1979 and way too late to save quad from doom!  But, the end-stage 
    decoders like the TATE II, Audionics Space & Image Composer, and the
    Sansui Vario-Matrix units are capable of 35-40db of separation!
       Although multi-channel sound has been experimented with both for 
    audio and in movies since at least the 1930s, it wasn't until 1969 
    that technology and the audio industry were ready to commercialize it.
    At the AES meeting in 1969 Vanguard records demonstrated DISCRETE 
    four-channel sound on a four-channel reel to reel deck.  Heads turned,
    production geared up and the first home quad recordings on open reel 
    tape were released in 1970. 
       Immediately following this...two developments are key, the 
    introduction of quadraphonic 8-track tapes (easily re-engineered from
    the stereo 8-tracks of the day) and the quest for some way to get
    quadraphonics into the commercial medium of the day........the lp.
      Peter Scheiber is credited with inventing the basic mathematical 
    matrix to encode four-channels into two, and then decode them back to
    four which he demonstrated in 1970 at the annual AES meeting.  CBS 
    bought the rights and named it SQ for Surround Quadraphonic.  CBS 
    went immediately to developing encoders/decoders and re-mixing albums
    into quadraphonic from their master-tape library.  SQ rolled out in 1972
    to great fanfare with units from Sony, Fisher, Lafayette, Marantz and
    Pioneer just to mention a few.
      With CBS as the largest record producer in the US holding the rights,
    the other record labels were hesitant to pay "royalties" to their the quest was on for something "better" and "owned" by
    ANYONE else.
      JVC of Japan, then a subsidiary of RCA worked on developing a 
    different method of encoding which resulted in the CD-4 system 
    (compatible-discrete 4 channel).  CD-4 used a deeper more sharply angled
    groove in the record capable of carrying frequencies of 20hz - 45khz to
    carry all four channels of information with a 30khz "carrier" frequency
    to demodulate the signals back into four channels.  This is the same
    method used for FM broadcasting which works great on the radio. But,
    vinyl was a different story!  Shibata of Japan developed a stylus 
    capable of reading the 20-45khz signal, and the encoder/demodulator was
    developed....but they had significant problems with the vinyl itself
    being able to hold the signals, and degradation due to playing was a
    real problem.  JVC then invented their "super" vinyl, and the wear issue 
    was finally overcome.  Introduction was in late 1973.  RCA now had a 
    competing format without the royalty consumers now
    had the problem!  Also, the "minor" record labels including Number 3, 
    ABC Records STILL had a royalties to RCA or CBS?
      At the same time Peter Scheiber was refining his matrix system, 
    Isao Itoh of Sansui was developing a very similar system which Sansui 
    named QS for Quadraphonic-Stereo.  They were really "leading" the pack,
    producing their first matrix "synthesizer" in 1970, and following in
    1971 with a commercial encoder.  But, being a hardware manufacturer was
    both a help and a hindrance!  They couldn't produce any music for the
    format!  Sansui offered QS to any and all record producers without any
    royalties.......they would make their money on the audio equipment and
    decoders!  The minor labels flocked to Sansui.....Vox, Turnabout, Ode,
    Ovation, and yep.....ABC!  The War was on...........
      Sansui along with all the other quad encoded formats were submitted 
    to the Electronic Industry Association of Japan and the Japan Phonograph
    Association in 1972 to try and clear up the pending disaster.  After
    much animosity the EIA-J and JPA designated the Sansui QS system as the
    "regular-matrix" or RM matrix for quadraphonics.  Of course, this was
    immediately rejected by CBS and RCA who had too much time and $$ 
    invested in developing their own systems.  And their industry clout in
    the US prevented ANY system from being designated the standard in the US.
      The RM designation did have one significant downside for Sansui though.
    It allowed all the other "hardware" manufacturers to include an RM
    decoder on their units without any royalty being paid to Sansui!  
      So, now you know why your Pioneer, or Marantz, or JVC, or just about
    any manufacturer OTHER than Sansui has an RM decoder and not a QS 
    decoder.  The battle raged.........The record producers pushed their
    artists and formats.  The hardware manufacturers were stuck trying to
    guess which system would prevail and who they should pay for the rights
    to produce the decoders in their unit.  And those of us as consumers
    busy swapping decoders and trying to hear something great (as we were
    told) from the lousy, poor separation SQ and QS decoders of the early
    seventies.  Or the alternative, the expensive and difficult to calibrate
    CD-4 system that gave us overly sensitive cartridges with plenty of
    noise and pops!  Most of the hardware manufacturers lined up behind a
    format and prayed that it would make it,and then offered outboard units
    for the other formats....just in case they were wrong!
      By 1975 the writing was on the wall.......the Record producers
    wouldn't give in, and the Audio companies were willing to do anything to
    keep the dream alive.  So it was then that the "second-generation" quad 
    receivers hit the market....all included SQ, QS (or RM), and CD-4 
    decoders built-in!   Set up the rest of your system, add your Pioneer 
    QX-949 or 747, Sansui QRX-7001/8001/9001, Kenwood KR-8840/9940 and play 
    any of the quad formats in mostly poor SQ, noisy CD-4, or the almost
    hidden QS quadraphonic records on your system! 
      Quadraphonic record production slowed.......RCA didn't introduce any
    new Quadradisc (CD-4) titles after 1975, SQ and QS held on...barely,
    with EMI/Angel finally stopping their classical series of SQ in 1979.
      And, the last QS titles were probably the DBX encoded Vox/Turnabout
    titles of 1979/80.
    "Quad" Bob

    Written By : Mr. Bob J Herndon
    Inspired By : Eero Aro

    List Compiled and Copyright By
    Mark Anderson

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