Editing Quadraphonic sound (section)

=== 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.