Patents
Sitemap › H04 - Electric communication technique › H04R - Loudspeakers, microphones, gramophone pick-ups or like acoustic electromechanical transducers; Deaf-aid sets; Public address systems › H04R 3 - Circuits for transducers
Patents for H04R 3 - Circuits for transducers (18,190)
12/1978
12/19/1978US4130725 Split-coil speaker with direct coupling
11/1978
11/28/1978US4127743 Muting circuit for loudspeaker
11/07/1978CA1041913A1 Loudspeaker compensation circuits
10/1978
10/24/1978US4122507 Loudspeaker overload circuit
10/10/1978US4119814 Hearing aid with adjustable frequency response
10/10/1978US4119812 Signal defect detection and compensation with signal de-emphasis
10/10/1978CA1040106A1 Multi-way speaker system
10/03/1978US4118600 Loudspeaker lower bass response using negative resistance and impedance loading
09/1978
09/12/1978US4113983 Input filtering apparatus for loudspeakers
09/05/1978US4112255 Rota-phonic system for stereo quadrophonic sound system
08/1978
08/29/1978US4110696 Audio eccentric connector plug
08/22/1978US4109107 Method and apparatus for frequency compensation of electro-acoustical transducer and its environment
08/15/1978CA1036503A1 Special effects generation and control system for motion pictures
08/08/1978US4105945 Active load circuits
08/08/1978US4105865 Audio distributor
07/1978
07/18/1978US4101840 Volume control arrangement for an electro-acoustic system
07/11/1978US4100380 Supervisory circuit for monitoring speaker coils
07/11/1978US4100371 Loudspeaker system with phase difference compensation
07/04/1978US4099025 Methods and means for avoiding false indications of activity in a multimicrophone system
06/1978
06/06/1978US4093822 Loudspeaker protection circuit
05/1978
05/30/1978US4092494 Loud-speaker enclosure with electrical feed-back
05/23/1978US4091236 Automatically tunable notch filter and method for suppression of acoustical feedback
05/16/1978US4090032 Control system for audio amplifying system having multiple microphones
05/09/1978US4088836 Acoustically responsive signal injection system for headphone users
05/09/1978US4088835 Comprehensive feedback elimination system employing notch filter
05/09/1978US4088834 Feedback elimination system employing notch filter
05/02/1978US4087633 Dereverberation system
05/02/1978US4087631 Projected sound localization headphone apparatus
04/1978
04/18/1978US4085365 Earphone adapter for aircraft radios
04/18/1978US4085299 Peak amplitude protection system for ribbon loudspeakers
04/18/1978US4084474 Selective high frequency compression device for speaker system
03/1978
03/28/1978US4081622 Electronic circuit for a speakerphone
03/14/1978US4079199 Acoustic feedback detector and automatic gain control
03/14/1978US4079197 Voice transcoder in helium atmosphere
02/1978
02/28/1978US4076204 Retaining clip
02/14/1978US4074070 Supersonic signal linearizes loudspeaker operation
01/1978
01/31/1978USRE29529 Equalization circuit
12/1977
12/20/1977US4064462 Acoustic feedback peak elimination unit
10/1977
10/18/1977US4054848 Ultrasonic oscillator
10/18/1977US4054751 Masking noise generator
10/04/1977US4052560 Loudspeaker distortion reduction systems
09/1977
09/13/1977US4048454 Sonic transducer employing rigid radiating member
09/13/1977US4048442 Stereophonic sound adaptor for simulating sound movement
08/1977
08/30/1977US4045748 Audio control system
08/16/1977US4042779 Coincident microphone simulation covering three dimensional space and yielding various directional outputs
08/09/1977US4041247 Method and apparatus for operation of carbon microphones at low average current levels
08/02/1977US4039753 Singing suppressor device
08/02/1977US4039750 Audio frequency phase modulator in hearing test system
07/1977
07/19/1977US4037222 Supervision of transducers
07/19/1977US4037051 Flat baffle speaker system having improved crossover
07/12/1977US4035672 Acoustic transducer with a dual purpose piezoelectric element
07/05/1977US4034268 Speaker protection circuit
06/1977
06/21/1977US4031321 Loudspeaker systems
06/21/1977US4031318 High fidelity loudspeaker system
05/1977
05/24/1977US4025722 Method and apparatus for recording
05/17/1977US4024535 Sound generating system for a sound masking package
05/10/1977US4023070 Electrical circuit for audio services
05/03/1977US4021614 Woofer equalizer
05/03/1977US4021611 Electronic hearing apparatus
04/1977
04/12/1977US4016953 Push-pull transducer system
03/1977
03/29/1977US4015089 Linear phase response multi-way speaker system
03/22/1977US4013845 Temperature compensating reproducing system
01/1977
01/11/1977US4002859 Multi-mode electrostatic microphone construction
01/11/1977US4002836 Audio signal distributor
12/1976
12/28/1976US4000370 Line level microphone with built in limiter
12/14/1976US3997725 Multidirectional sound reproduction systems
12/14/1976US3997724 Loudspeaker drive mechanism monitoring assembly
11/1976
11/30/1976US3995113 Two-way acoustic communication through the ear with acoustic and electric noise reduction
11/16/1976US3992586 Boardroom sound reinforcement system
11/16/1976US3992585 Self-energizing electrostatic loudspeaker system
11/16/1976US3992584 Automatic microphone mixer
11/02/1976US3989963 Control circuits for piezo electric transducers
10/1976
10/26/1976US3988541 Method and apparatus for frequency compensation of electro-mechanical transducer
10/19/1976US3987245 Compensated speaker-microphone
10/05/1976US3984704 Device for correcting the frequency response of an electromechanical transducer
10/05/1976US3984635 Low range loudspeaker system
09/1976
09/21/1976US3982071 Multichannel sound signal processing system employing voltage controlled amplifiers
08/1976
08/10/1976US3973839 Special effects generation and control system for motion pictures
06/1976
06/01/1976US3961202 Power supply circuit for use with an electrostatic transducer
05/1976
05/11/1976US3956716 Pulse width modulated signal amplifier
04/1976
04/06/1976US3949325 Audio equalizers for large rooms
03/1976
03/16/1976US3944756 Electret microphone
03/16/1976US3944754 Record disc recording system with signal amplitude controlled by stylus arm position
03/16/1976US3944735 Directional enhancement system for quadraphonic decoders
03/09/1976US3943411 Overload protection and display circuit, particularly for sound radiators
03/02/1976US3941932 Loudspeaker having a voice coil and a piezoelectric feedback transducer
02/1976
02/24/1976US3940709 Equalization circuit
02/10/1976US3937887 Acoustic power system
01/1976
01/20/1976US3934158 Switching circuit
01/06/1976US3931469 Crossover network for a multi-element electrostatic loudspeaker system
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