| Patents for H04S 3 - Systems employing more than two channels, e.g. quadraphonic (4,597) |
|---|
| 06/12/1990 | US4933768 Sound reproducer |
| 06/06/1990 | CA2004581A1 Room sound reproducing |
| 06/05/1990 | US4932060 Stereo electroacoustical transducing |
| 06/05/1990 | US4932059 Variable matrix decoder for periphonic reproduction of sound |
| 03/14/1990 | EP0358295A2 Sum/differential signal processing circuit |
| 02/27/1990 | US4905284 Audio system for vehicular applications |
| 02/27/1990 | US4905283 Surround decoder |
| 02/14/1990 | EP0354519A2 Surround decoder |
| 02/14/1990 | EP0354517A2 Center mode control circuit |
| 01/31/1990 | EP0352627A2 Sound reproducer |
| 01/30/1990 | US4897877 Sub-woofer driver combination with dual voice coil arrangement |
| 01/25/1990 | WO1990000851A1 Improvements in or relating to sound reproduction systems |
| 01/02/1990 | US4891839 Signal re-distribution, decoding and processing in accordance with amplitude, phase and other characteristics |
| 12/12/1989 | US4887045 Sum/differential signal processing circuit |
| 11/21/1989 | US4882753 Passive ambience recovery system for the reproduction of sound |
| 10/10/1989 | US4873722 Multi-channel reproducing system |
| 09/19/1989 | US4868682 Method of recording and reproducing video and sound information using plural recording devices and plural reproducing devices |
| 08/29/1989 | US4862502 Sound reproduction |
| 08/02/1989 | EP0325650A1 Extended imaging split mode loudspeaker system |
| 07/26/1989 | EP0325175A2 Multi-channel stereophonic system |
| 07/18/1989 | US4850021 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 |
| 07/12/1989 | EP0323904A2 Sound reproduction |
| 07/12/1989 | EP0323830A2 Surround-sound system |
| 06/20/1989 | US4841573 Stereophonic signal processing circuit |
| 06/06/1989 | US4837825 Passive ambience recovery system for the reproduction of sound |
| 04/27/1989 | DE3734084A1 Method of reproducing multichannel sound signals |
| 04/04/1989 | US4819269 Extended imaging split mode loudspeaker system |
| 03/21/1989 | US4815133 Sound field producing apparatus |
| 02/21/1989 | US4807217 Multi-channel stereo reproducing apparatus |
| 01/26/1989 | WO1989000802A1 Extended imaging split mode loudspeaker system |
| 01/17/1989 | US4799260 Variable matrix decoder |
| 09/28/1988 | EP0284286A2 Stereo electroacoustical transducing |
| 05/24/1988 | US4747142 Three-track sterophonic system |
| 04/06/1988 | EP0262216A1 Sound encoding system |
| 01/13/1988 | EP0252102A1 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. |
| 12/23/1987 | EP0249640A1 Multi-channel stereo reproducing apparatus |
| 12/03/1987 | DE3618033A1 Circuit arrangement for stereo reproduction |
| 11/03/1987 | US4704728 Signal re-distribution, decoding and processing in accordance with amplitude, phase, and other characteristics |
| 10/27/1987 | US4703502 Stereo signal reproducing system |
| 10/22/1987 | WO1987006423A1 Sound encoding system |
| 09/22/1987 | US4696036 Directional enhancement circuit |
| 08/18/1987 | CA1225599A1 Signal decoding system |
| 08/04/1987 | US4685136 For automatically equalizing a first signal and a second signal |
| 07/14/1987 | US4680796 Sound encoding system |
| 06/18/1987 | WO1987003771A1 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 |
| 06/04/1987 | WO1987003449A1 Multi-channel stereo reproducing apparatus |
| 05/13/1987 | CN86203757U Closed loop frequency-dividing sound-reproducing system |
| 04/28/1987 | CA1221168A1 Improvements in sterophonic motion picture sound-tracks compatible with different sound projection formats and record and playback apparatus therefor |
| 01/20/1987 | US4638506 Sound field simulation system and method for calibrating same |
| 01/20/1987 | US4638505 Optimized low frequency response of loudspeaker systems having main and sub-speakers |
| 12/16/1986 | US4630298 Method and apparatus for reproducing sound having a realistic ambient field and acoustic image |
| 11/11/1986 | US4622689 Stereophonic sound system |
| 10/22/1986 | CN86102314A 可变矩阵译码器 Variable matrix decoder |
| 10/21/1986 | US4618987 Large-area acoustic radiation system |
| 09/30/1986 | US4615043 Triphonic sound system |
| 09/16/1986 | US4612663 Multichannel audio reproduction system |
| 06/10/1986 | US4594730 Apparatus and method for enhancing the perceived sound image of a sound signal by source localization |
| 06/10/1986 | US4594729 Method of and apparatus for the stereophonic reproduction of sound in a motor vehicle |
| 05/13/1986 | US4589129 Signal decoding system |
| 04/01/1986 | CA1202572A1 Systems of speaker arrangements |
| 04/01/1986 | CA1202571A1 Triphonic sound system |
| 03/18/1986 | US4577305 Stereophonic motion picture photographic sound-tracks compatible with different sound projection formats and record and playback apparatus therefore |
| 02/05/1986 | EP0169873A1 A stereophonic sound system |
| 12/31/1985 | CA1198683A1 Method and apparatus for reproducing sound having a realistic ambient field and acoustic image |
| 08/20/1985 | US4536716 Stereo amplifier circuit for bichannel signals |
| 08/15/1985 | WO1985003616A1 A stereophonic sound system |
| 07/30/1985 | US4532647 Automatic dimension control for a directional enhancement system |
| 06/25/1985 | US4525855 Variable rate and variable limit dimension controls for a directional enhancement system |
| 06/11/1985 | CA1188624A1 Fm stereo apparatus and method |
| 06/04/1985 | US4521906 Speaker systems for producing balanced stereo images at multiple locations |
| 05/07/1985 | US4516257 Triphonic sound system |
| 12/18/1984 | US4489432 Method and apparatus for reproducing sound having a realistic ambient field and acoustic image |
| 10/23/1984 | CA1176709A1 Circuit for minimizing the effects of the level of received broadcast signals on separation in a stereophonic receiver |
| 10/03/1984 | EP0120126A2 Systems of speaker arrangements |
| 09/19/1984 | EP0119101A2 Improvements in stereophonic motion picture photographic sound-tracks and apparatus for recording and playing back photographic sound tracks |
| 06/26/1984 | US4457012 FM Stereo apparatus and method |
| 04/17/1984 | US4443889 Acoustic apparatus and method |
| 02/22/1984 | EP0100805A1 Device for the sonic reproduction of a stereophonic record |
| 01/11/1984 | EP0097982A2 FM stereo apparatus |
| 12/07/1983 | EP0046765B1 Sound reproduction systems |
| 11/29/1983 | US4418243 Acoustic projection stereophonic system |
| 11/22/1983 | CA1157382A1 High fidelity stereophonic reproduction system |
| 11/08/1983 | US4414430 Decoders for feeding irregular loudspeaker arrays |
| 10/04/1983 | US4408095 Acoustic apparatus |
| 08/24/1983 | EP0086287A1 Improved acoustic apparatus and method |
| 07/05/1983 | US4392019 Surround sound system |
| 05/03/1983 | US4382157 Multiple speaker type sound producing system |
| 04/06/1983 | EP0075615A1 Sound field simulation system and method for calibrating same |
| 01/18/1983 | US4369335 Two-channel, four loudspeaker-component enhanced sterophonic system |
| 11/09/1982 | CA1135196A1 Microphone system for producing signals for surround-sound transmission and reproduction |
| 10/05/1982 | US4352953 Multichannel non-discrete audio reproduction system |
| 03/10/1982 | EP0046765A1 Sound reproduction systems. |
| 03/09/1982 | CA1119527A1 Multi-dimensional audio projector |
| 02/16/1982 | US4316058 Sound field transmission system surrounding a listener |
| 02/16/1982 | CA1118363A1 Varying loudspeaker spatial characteristics |
| 10/06/1981 | US4293821 Audio channel separating apparatus |
| 09/03/1981 | WO1981002502A1 Sound reproduction systems |
| 08/04/1981 | US4282605 Sound reproducing with remote amplifying transducer |
| 06/23/1981 | US4275267 Ambience processor |
| 05/12/1981 | CA1100881A1 Sound system apparatus and format |