Matrix (sound recording)

In sound recording, a matrix can refer to a disc in the early stages of processing a record for mass production; see mastering and pressing process discussion at gramophone record. Matrix can also refer to the encoding of several channels of audio into fewer channels to be decoded back into several channels later.

SQ Matrix ("Surround Quadraphonic", "Stereo Quadraphonic", CBS SQ)

Encoding Matrix	Left Front	Right Front	Left Back	Right Back
Left Total	1.0	0.0	j0.7	k0.7
Right Total	0.0	1.0	k0.7	j0.7

j = + 90º phase-shift , k = - 90º phase-shift

QS Matrix ("Quadraphonic Stereo", QS)

Encoding Matrix	Left Front	Right Front	Left Back	Right Back
Left Total	0.92	0.38	j0.92	j0.38
Right Total	0.38	0.92	k0.38	k0.92

j = + 90º phase-shift , k = - 90º phase-shift

Ambisonics UHJ coding matrix

Encoding Matrix	X (front-back information)	W (pressure signal)	Y (left-right information)
Left Total	0.093 + j0.255	0.470 + k0.171	+0.328
Right Total	0.093 + k0.255	0.470 + j0.171	-0.328

j = + 90º phase-shift , k = - 90º phase-shift

Dolby Surround Matrix

Encoding Matrix	Left	Right	Center	Surround
Left Total	1.000	0.000	0.707	j0.707
Right Total	0.000	1.000	0.707	k0.707

j = + 90º phase-shift , k = - 90º phase-shift

Dolby Pro Logic Matrix

Encoding Matrix	Left	Right	Center	Rear Left	Rear Right
Left Total	1.000	0.000	0.707	j0.707	j0.707
Right Total	0.000	1.000	0.707	k0.707	k0.707

j = + 90º phase-shift , k = - 90º phase-shift

Dolby Pro Logic II Matrix

Encoding Matrix	Left	Right	Center	Rear Left	Rear Right
Left Total	1.000	0.000	0.707	j0.8165	j0.5774
Right Total	0.000	1.000	0.707	k0.5774	k0.8165

j = + 90º phase-shift , k = - 90º phase-shift

See also

* Quadraphonic
* Surround_sound