GB1396352A - Apparatus for reproducing quadraphonic sound - Google Patents
Apparatus for reproducing quadraphonic soundInfo
- Publication number
- GB1396352A GB1396352A GB2958472A GB2958472A GB1396352A GB 1396352 A GB1396352 A GB 1396352A GB 2958472 A GB2958472 A GB 2958472A GB 2958472 A GB2958472 A GB 2958472A GB 1396352 A GB1396352 A GB 1396352A
- Authority
- GB
- United Kingdom
- Prior art keywords
- signals
- signal
- output
- adders
- logic circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04S—STEREOPHONIC SYSTEMS
- H04S3/00—Systems employing more than two channels, e.g. quadraphonic
- H04S3/02—Systems employing more than two channels, e.g. quadraphonic of the matrix type, i.e. in which input signals are combined algebraically, e.g. after having been phase shifted with respect to each other
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Algebra (AREA)
- General Physics & Mathematics (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Mathematical Physics (AREA)
- Pure & Applied Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Stereophonic System (AREA)
- Stereo-Broadcasting Methods (AREA)
Abstract
1396352 Quadraphonic systems CBS Inc 23 June 1972 [23 June 1971] 29584/72 Heading H4 A decoding matrix, Fig. 2A, for quadraphonic signals coded by the arrangement described in Specification 1,387,874, producing L T and R T signals as shown at 38 and 40; derives four signals 90, 92, 94, 96, containing respectively predominant L # , Lb, Rb and R # in a conventional fashion using phase shift networks 46 to 52 and adders 70, 72, as described in Specifications 1,387,874 and 1,379,771. The signals L<SP>1</SP> # and R1 # are each combined with a minor proportion of the other signal in adders 98, 100, to produce the signals L<SP>11</SP> # and R<SP>11</SP> # for reproduction at the front corners of the listening area. Similarly the signals L<SP>1</SP>b and R<SP>1</SP> b are each combined with minor proportions of the other in adders 102 and 104 to produce the signal L<SP>11</SP> b and R11 b for reproduction in the rear corners of the listening area. Gain controlled amplifiers 74-80, are provided to feed the reproducers and are controlled by the logic circuit, Fig. 2b. The major portion of the logic circuit is similar to that described in Specification 1,387,873, and comprises a wave matching logic, producing at the output of difference circuit 172 a signal indicating predominance of front left or right signals by one polarity of output and predominance of rear left or right signals by the other polarity of output. In addition adders 190, 192 and difference circuit 206, which are similar to the "front-back" logic circuit of Specification 1,387,874, provide discrimination between a front centre signal and a rear centre signal to provide an appropriate output signal at 208. Signals at 208 above a predetermined threshold defined by diodes 210 and 212, are applied to adder 176, together with the output of the other logic circuit from 174, to provide gain switching potentials on lines 179 and 181 which differentially vary the gains of the amplifiers feeding the front speakers relative that of the amplifiers feeding the rear speakers.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US15597671A | 1971-06-23 | 1971-06-23 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1396352A true GB1396352A (en) | 1975-06-04 |
Family
ID=22557545
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB2958472A Expired GB1396352A (en) | 1971-06-23 | 1972-06-23 | Apparatus for reproducing quadraphonic sound |
Country Status (10)
Country | Link |
---|---|
US (1) | US3798373A (en) |
JP (1) | JPS5110963B1 (en) |
AU (1) | AU464001B2 (en) |
BE (1) | BE785279A (en) |
CA (1) | CA973806A (en) |
DE (1) | DE2230842C3 (en) |
FR (1) | FR2143325B1 (en) |
GB (1) | GB1396352A (en) |
IT (1) | IT958512B (en) |
NL (1) | NL7208607A (en) |
Families Citing this family (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1398786A (en) * | 1971-08-06 | 1975-06-25 | Sony Corp | Multisignal transmission apparatus |
DE2252132C3 (en) | 1972-10-24 | 1982-08-26 | Sansui Electric Co., Ltd., Tokyo | Decoder for a 4-2-4 matrix system |
JPS5527517B2 (en) * | 1972-12-01 | 1980-07-21 | ||
JPS5320343B2 (en) * | 1973-03-29 | 1978-06-26 | ||
GB1514162A (en) * | 1974-03-25 | 1978-06-14 | Ruggles W | Directional enhancement system for quadraphonic decoders |
US3937885A (en) * | 1974-09-06 | 1976-02-10 | Motorola, Inc. | Control circuit for a matrixed four channel audio reproducing system |
JPS5453831U (en) * | 1977-09-22 | 1979-04-13 | ||
JPS54137248U (en) * | 1978-03-17 | 1979-09-22 | ||
US5046098A (en) * | 1985-03-07 | 1991-09-03 | Dolby Laboratories Licensing Corporation | Variable matrix decoder with three output channels |
US4799260A (en) * | 1985-03-07 | 1989-01-17 | Dolby Laboratories Licensing Corporation | Variable matrix decoder |
US4862502A (en) * | 1988-01-06 | 1989-08-29 | Lexicon, Inc. | Sound reproduction |
US5136650A (en) * | 1991-01-09 | 1992-08-04 | Lexicon, Inc. | Sound reproduction |
US5796844A (en) * | 1996-07-19 | 1998-08-18 | Lexicon | Multichannel active matrix sound reproduction with maximum lateral separation |
US5870480A (en) * | 1996-07-19 | 1999-02-09 | Lexicon | Multichannel active matrix encoder and decoder with maximum lateral separation |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3632886A (en) * | 1969-12-29 | 1972-01-04 | Peter Scheiber | Quadrasonic sound system |
US3646574A (en) * | 1970-05-25 | 1972-02-29 | Howard S Holzer | Compatible stereo generator |
US3684835A (en) * | 1970-07-29 | 1972-08-15 | Parasound Inc | Four channel stereo synthesizer |
-
1971
- 1971-06-23 US US00155976A patent/US3798373A/en not_active Expired - Lifetime
-
1972
- 1972-06-13 CA CA144,532A patent/CA973806A/en not_active Expired
- 1972-06-22 BE BE785279A patent/BE785279A/en unknown
- 1972-06-22 AU AU43775/72A patent/AU464001B2/en not_active Expired
- 1972-06-22 NL NL7208607A patent/NL7208607A/xx not_active Application Discontinuation
- 1972-06-22 FR FR7222631A patent/FR2143325B1/fr not_active Expired
- 1972-06-23 IT IT51115/72A patent/IT958512B/en active
- 1972-06-23 GB GB2958472A patent/GB1396352A/en not_active Expired
- 1972-06-23 DE DE2230842A patent/DE2230842C3/en not_active Expired
- 1972-06-23 JP JP47063100A patent/JPS5110963B1/ja active Pending
Also Published As
Publication number | Publication date |
---|---|
DE2230842B2 (en) | 1980-02-21 |
BE785279A (en) | 1972-10-16 |
CA973806A (en) | 1975-09-02 |
DE2230842C3 (en) | 1980-10-16 |
FR2143325A1 (en) | 1973-02-02 |
FR2143325B1 (en) | 1979-04-06 |
AU4377572A (en) | 1974-01-03 |
IT958512B (en) | 1973-10-30 |
NL7208607A (en) | 1972-12-28 |
US3798373A (en) | 1974-03-19 |
JPS5110963B1 (en) | 1976-04-08 |
DE2230842A1 (en) | 1972-12-28 |
AU464001B2 (en) | 1975-08-14 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed [section 19, patents act 1949] | ||
PCNP | Patent ceased through non-payment of renewal fee |