Quad

See Quadraphonic, Quadruplex.

Quadraphonic

An audio system that records sound using four separate channels to be played through four separate speakers.

Quadruplex

A 2 in. reel-to-reel videotape format for a system that uses four recording heads.  Developed by Ampex in the mid-1950s, it remained a widely used broadcasting standard until the late 1970s.  A 2 in. Quad videocartridge was marketed by RCA.

See also:

Glossary