Editing Quadraphonic sound (section)

==== QS Regular Matrix and SQ Quadraphonic ====

[[File:Sansui QS-1 Synthesizer.jpg|thumbnail|Sansui QS sound decoder]]
Improved systems based on [[Peter Scheiber]]'s work on utilizing 90-degree phase-shift circuitry came later, namely the ''[[QS Regular Matrix|QS]]'' and ''[[Stereo Quadraphonic|SQ]]'' systems.

The first of these, known as ''QS'', was developed by [[Sansui Electric]]. A so-called matrix format, it utilized four sound channels, which were encoded into two stereo album tracks. These were then decoded into the original four sound channels. The QS system debuted in the United States in March 1971 and was improved by their ''Vario-Matrix'' system in 1973.{{Citation needed|date=January 2012}}

The second, ''SQ'', was developed and marketed by [[Columbia Records]] and [[Sony]] and entered the US market in April 1971. The ''SQ'' format was also used by companies such as [[EMI]] in Great Britain, who pressed several ''SQ'' album releases. The sound separation of the ''SQ'' system was greatly improved by the introduction of ''SQ Full Logic'' decoding in 1975 using the Motorola chips MC1312, MC1314 & MC1315.<ref>{{Cite web|url=https://datasheetspdf.com/pdf/570327/Motorola/MC1312P/1|title = MC1312P SYSTEM Datasheet PDF - DECODER SYSTEM. Equivalent, Catalog}}</ref>

Both SQ and QS had significant support from major record companies and hardware manufacturers during the 1970s. They also achieved notable sales and market penetration. Unfortunately, due to the similarities in name and technology these could easily be confused by the public.