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Priority claimed from GB3318765Aexternal-prioritypatent/GB1059055A/en
Priority claimed from GB2140166Aexternal-prioritypatent/GB1139770A/en
Application filedfiledCritical
Publication of NL6706647ApublicationCriticalpatent/NL6706647A/xx
H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
H04R1/00—Details of transducers, loudspeakers or microphones
H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
H04R1/32—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only
H04R1/40—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by combining a number of identical transducers
H04R1/406—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by combining a number of identical transducers microphones