Editing Quadraphonic sound (section)

==== EV-4/Stereo-4 and Dynaquad (DY) ====

The first of these were basic systems with relatively poor performance developed by [[Electro-Voice]] (''[[Stereo-4|EV-4/Stereo-4]]'') and [[Dynaco]] (''[[Dynaquad|Dynaquad (DY)]]''). 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. But with poor decode performance, these systems failed to match the accuracy or channel independence of later matrix formats.

The original systems (DY and EV-4) suffered from low front left-right separation (around 12&nbsp;dB) and a poor rear left-right separation of 2&nbsp;dB. The decoders were designed more to give an effect rather than accurate decoding, which was mainly due to limitations in both systems. Since both systems were very closely related mathematically, users only needed one decoder of either system to playback albums of both systems.

The differences between the early and late matrix systems were so vast, it made decoding DY/EV-4 with either SQ or QS decoders with accuracy impossible; the results often being a ''smeared'' or poorly defined sound stage, which could be vastly different from what was intended by the producer or recording engineer.<ref>{{cite journal
| last1        = Scheiber
| first1       = Peter
| author-link1  = Peter Scheiber
|date= December 1969
| title        = Toward a More Accurate Spatial Environment
| journal      = Journal of the Audio Engineering Society
| volume       = 17
| issue        = 6
| pages        = 690, 691
| publisher    = [[Audio Engineering Society]]
}}</ref><ref>{{cite journal
| last1        = Scheiber
| first1       = Peter
| author-link1  = Peter Scheiber
|date= November 1971
| title        = Analyzing Phase-Amplitude Matrices
| journal      = Journal of the Audio Engineering Society
| volume       = 19
| issue        = 10
| pages        = 835–839
| publisher    = [[Audio Engineering Society]]
}}</ref>