H
ELECTRICITY
H
ELECTRICITY
H04
ELECTRIC COMMUNICATION TECHNIQUE
H04
ELECTRIC COMMUNICATION TECHNIQUE
H04R
LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
H04R
LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
1/00
Details of transducers,; loudspeakers or microphones
1/00
Details of transducers,; loudspeakers or microphones
H04R1/20
Arrangements for obtaining desired frequency or directional characteristics
H04R1/20
Arrangements for obtaining desired frequency or directional characteristics
H04R1/22
for obtaining desired frequency characteristic only
H04R1/22
for obtaining desired frequency characteristic only
H04R1/28
Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means
H04R1/28
Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means
H04R1/2807
Enclosures comprising vibrating or resonating arrangements
H04R1/2807
Enclosures comprising vibrating or resonating arrangements
H04R1/2838
of the bandpass type
H04R1/2838
of the bandpass type
H04R1/2846
Vents, i.e. ports, e.g. shape thereof or tuning thereof with damping material
H04R1/2846
Vents, i.e. ports, e.g. shape thereof or tuning thereof with damping material