using three or more audio channels, e.g. triphonic or quadraphonic

Full Title

Arrangements for broadcast or for distribution combined with broadcast > Arrangements characterised by special technical features of the broadcast information, e.g. signal form or information format > Stereophonic broadcast systems > using three or more audio channels, e.g. triphonic or quadraphonic

Classification Context

Section:

ELECTRICITY

Class:

ELECTRIC COMMUNICATION TECHNIQUE

Subclass:

BROADCAST COMMUNICATION