Patents
Sitemap › H04 - Electric communication technique › H04S - Stereophonic systems › H04S 3 - Systems employing more than two channels, e.g. quadraphonic
Patents for H04S 3 - Systems employing more than two channels, e.g. quadraphonic (4,597)
12/1993
12/01/1993EP0571455A1 Sound reproduction system
11/1993
11/30/1993CA2021816C Loudspeaker system
11/23/1993US5265166 Multi-channel sound simulation system
11/16/1993US5263087 Time constant processing circuit for surround processor
11/09/1993US5260920 Acoustic space reproduction method, sound recording device and sound recording medium
10/1993
10/26/1993US5257313 Surround audio apparatus
10/19/1993US5255326 Interactive audio control system
10/08/1993CA2067620A1 Surround-tec j-50 surround sound adapter
10/05/1993US5251260 Audio surround system with stereo enhancement and directivity servos
09/1993
09/30/1993DE4209544A1 Verfahren zum Übertragen oder Speichern digitalisierter, mehrkanaliger Tonsignale A method of transmitting or storing digitized, multi-channel audio signals
09/16/1993WO1993018630A1 Surround sound apparatus
08/1993
08/31/1993CA1321756C Sound field reproducing apparatus
08/04/1993EP0553832A1 Sound field controller
06/1993
06/30/1993EP0517848A4 Sound mixing device
06/24/1993WO1993012517A1 Acoustic equipment and method of displaying operating thereof
06/22/1993US5222145 Dual-chamber multi-channel speaker for surround sound stereo audio systems
06/22/1993US5222059 Surround-sound system with motion picture soundtrack timbre correction, surround sound channel timbre correction, defined loudspeaker directionality, and reduced comb-filter effects
06/09/1993DE4241130A1 Producing two channel sound field - using successive addition and subtraction of initial front and rear left and right signals to obtain left and right channel signals for headphones
06/02/1993EP0544232A2 Sound collecting system and sound reproducing system
05/1993
05/18/1993US5212733 Sound mixing device
05/13/1993WO1993009645A1 Process for simultaneously transmitting signals from n-signal sources
05/13/1993WO1993009643A1 Multi-channel sound simulation system
05/13/1993DE4237710A1 Improving head related sound characteristics for TV audio signal playback - using controlled audio signal processing for conversion into stereo audio signals
05/13/1993CA2122268A1 Multi-channel sound simulation system
05/06/1993DE4135977A1 Verfahren zur gleichzeitigen uebertragung von signalen aus n-signalquellen Process for the simultaneous transmission of signals from n-signal sources
05/06/1993DE4135747A1 Multichannel sound signal transmission procedure with interference correction - using introduced time difference between transmitted signal preceded by defined phase difference used to provide matrix signals
03/1993
03/31/1993EP0533757A1 Surround processor
03/30/1993US5199075 Surround sound loudspeakers and processor
03/23/1993US5197100 Audio circuit for a television receiver with central speaker producing only human voice sound
03/23/1993US5197099 Multiple-channel audio reproduction apparatus
03/09/1993US5193118 Vehicular sound reproducing
02/1993
02/24/1993EP0249640B1 Multi-channel stereo reproducing apparatus
02/23/1993US5189703 Timbre correction units for use in sound systems
02/10/1993EP0526880A2 Audio surround system with stereo enhancement and directivity servos
02/03/1993EP0526136A2 System for calibrating sound field
01/1993
01/19/1993US5181249 Three channel audio transmission and/or reproduction systems
01/05/1993US5177798 Sound reproducer for high definition television
01/05/1993CA1312369C Sound reproducer
12/1992
12/30/1992EP0520068A1 Encoder/decoder for multidimensional sound fields.
12/23/1992EP0519055A1 Decoder for variable-number of channel presentation of multidimensional sound fields.
12/16/1992EP0517848A1 Sound mixing device
12/15/1992US5172415 Surround processor
12/02/1992EP0516183A1 Television receiver
12/01/1992CA1310919C Surround-sound system
11/1992
11/17/1992US5165097 Controller for acoustic apparatus
09/1992
09/30/1992WO1993019542A2 Process for transmitting or storing digitalized, multi-channel audio signals
09/23/1992CN2117011U Audio amplifier unit
09/03/1992WO1992015180A1 Sound reproduction system
08/1992
08/26/1992EP0500049A1 Recording apparatus, and recording/reproducing system
08/04/1992US5136650 Sound reproduction
07/1992
07/23/1992WO1992012608A1 Decoder for variable-number of channel presentation of multidimensional sound fields
07/23/1992WO1992012607A1 Encoder/decoder for multidimensional sound fields
07/21/1992CA1305550C Stereo electroacoustical transducing
07/07/1992US5128999 Sound field correcting apparatus
06/1992
06/30/1992US5125732 Motion picture exhibition facility
06/16/1992US5123051 Sound field reproducing apparatus
06/02/1992CA1302298C Center mode control circuit for sound system
06/02/1992CA1302297C Surround decoder
05/1992
05/06/1992EP0483950A2 Sound field correcting apparatus
05/05/1992US5111508 Audio system for vehicular application
04/1992
04/28/1992US5109423 Audio system with amplifier and signal device
04/14/1992US5105412 Recording medium playing apparatus for correcting audio signals using an appropriate sound field
03/1992
03/31/1992CA1298208C Extended imaging split mode loudspeaker system
03/18/1992EP0252102B1 A method and a circuit for decoding four-channel signals which are coded in a matrix and available in the form of a two-channel signal
03/12/1992DE4125893A1 Audio reproduction system for motor vehicle - has multiple loudspeakersoperated to compensate for insufficiencies of acoustics insidevehicle
02/1992
02/05/1992CN1058502A Surround sound effect control device
02/04/1992CA1295262C Sum/differential signal processing circuit
01/1992
01/22/1992EP0467256A2 Surround sound effect control device
01/15/1992EP0466435A2 Surround audio apparatus
12/1991
12/17/1991US5073945 Loudspeaker system
12/09/1991WO1991019407A1 Surround processor
12/09/1991CA2084512A1 Surround processor
09/1991
09/05/1991WO1991013497A1 Sound mixing device
09/04/1991CN1013822B Variable matrix decoder
09/03/1991US5046098 Variable matrix decoder with three output channels
08/1991
08/27/1991US5043970 Sound system with source material and surround timbre response correction, specified front and surround loudspeaker directionality, and multi-loudspeaker surround
08/13/1991US5040220 Control circuit for controlling reproduced tone characteristics
07/1991
07/25/1991DE4102078A1 Reverberation effect audio device - generates audio signals with coeffts. of level attenuation depending on registered loudness of basic signal
07/23/1991US5033577 Room sound reproducing
07/03/1991EP0434691A1 Improvements in or relating to sound reproduction systems.
05/1991
05/14/1991CA1284112C Variable matrix decoder
04/1991
04/04/1991WO1991001544A3 Vehicular sound reproducing
04/02/1991US5004067 Cinema sound system for unperforated screens
02/1991
02/13/1991EP0412725A2 Sound reproduction apparatus
02/07/1991WO1991001544A2 Vehicular sound reproducing
02/06/1991EP0411786A1 Vehicular sound reproducing
01/1991
01/30/1991EP0410352A2 Loudspeaker system
01/18/1991CA2021243A1 Vehicular sound reproducing
01/17/1991DE3930278C1 Establishing stereo telephone connection - using integrated digital communication system for coualing two useful data channels and signalling channel
12/1990
12/27/1990EP0404117A2 Surround-sound system
12/25/1990US4980915 Center mode control circuit
10/1990
10/23/1990US4965674 Recording and reproducing system with selective matrix conversion
10/18/1990WO1990012476A1 Process and device for distribution of sound among several sound sources
10/18/1990WO1990012475A1 Circuit for modulation and distribution of alternative electric power
08/1990
08/28/1990US4953219 Stereo signal reproducing system using reverb unit
08/28/1990US4953213 Surround mode stereophonic reproducing equipment
07/1990
07/26/1990DE3932984A1 Stereophonic audio signal reproduction system - has front and rear speakers operated in different modes by selectors
07/10/1990US4941177 Variable matrix decoder
06/1990
06/28/1990WO1990007252A1 Stereo sound system
06/13/1990EP0372830A2 Room sound reproducing
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