Quadraphonic sound

sound that uses four channels in which speakers are positioned at the four corners of the listening space

magnetic tape sound recording technology

Quaudiophiliac (styled QuAUDIOPHILIAc) is a compilation album featuring music by Frank Zappa, released in DVD-Audio format by Barking Pumpkin Records in 2004. It compiles recordings he made while experimenting with quadraphonic, or four-channel, sound in the 1970s. Zappa prepared quadraphonic mixes of a number of his 1970s albums, with both Over-Nite Sensation (1973) and ''Apostrophe (')'' (1974) being released in discrete quadraphonic on Zappa's DiscReet Records label.