DIFF Main Group
H04R 27/00 Public address systems (circuits for preventing acoustic reaction H04R3/02; circuits for distributing signals to loudspeakers H04R3/12; ; amplifiers H03F)
Introduced: September 1968
Title
Titles differ between systems:
IPC: Public address systems
CPC: Public address systems (circuits for preventing acoustic reaction H04R3/02; circuits for distributing signals to loudspeakers H04R3/12; ; amplifiers H03F)
Full Title
Full titles differ between systems:
IPC:
Public address systems
CPC:
Public address systems (circuits for preventing acoustic reaction H04R3/02; circuits for distributing signals to loudspeakers H04R3/12; ; amplifiers H03F)
IPC and CPC are identically structured here. All 2 subcodes exist in both systems.
Child Classifications
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