Template:Quadraphonic sound

v t e Quadraphonic sound
Discrete (4:4:4) formats	Q4 (1969) Quad-8 (1970) CD-4 (1972) UD-4 (1973)
Matrix (4:2:4) formats	Stereo-4 (1970) DY (1971) SQ (1971) QS (1971) Matrix H (1977)
Derived (2:2:4) formats	Hafler circuit (1969) DY (1969)
Concepts	Quadraphonic sound Matrix decoder Precedence effect Four-channel Compact Disc Digital Audio