GB1447814A – Matrix four-channel decoding system
– Google Patents
GB1447814A – Matrix four-channel decoding system
– Google Patents
Matrix four-channel decoding system
Info
Publication number
GB1447814A
GB1447814A
GB3603474A
GB3603474A
GB1447814A
GB 1447814 A
GB1447814 A
GB 1447814A
GB 3603474 A
GB3603474 A
GB 3603474A
GB 3603474 A
GB3603474 A
GB 3603474A
GB 1447814 A
GB1447814 A
GB 1447814A
Authority
GB
United Kingdom
Prior art keywords
decoder
high frequency
gain
low
coefficients
Prior art date
1973-08-20
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
Application number
GB3603474A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sansui Electric Co Ltd
Original Assignee
Sansui Electric Co Ltd
Priority date (The priority date 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 date listed.)
1973-08-20
Filing date
1974-08-15
Publication date
1976-09-02
1974-08-15
Application filed by Sansui Electric Co Ltd
filed
Critical
Sansui Electric Co Ltd
1976-09-02
Publication of GB1447814A
publication
Critical
patent/GB1447814A/en
Status
Expired
legal-status
Critical
Current
Links
Espacenet
Global Dossier
Discuss
Classifications
H—ELECTRICITY
H04—ELECTRIC COMMUNICATION TECHNIQUE
H04H—BROADCAST COMMUNICATION
H04H20/00—Arrangements for broadcast or for distribution combined with broadcast
H04H20/86—Arrangements characterised by the broadcast information itself
H04H20/88—Stereophonic broadcast systems
H04H20/89—Stereophonic broadcast systems using three or more audio channels, e.g. triphonic or quadraphonic
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
Abstract
1447814 Quadraphonic decoders; gain control SANSUI ELECTRIC CO Ltd 15 Aug 1974 [20 Aug 1973] 36034/74 Heading H4R In a 2-4 quadraphonic decoder in which the matrix coefficients are automatically varied according to the instantaneous amplitude relationship between the directional components in the two composite input signals, the decoded front and rear channel pairs are fed to respective mixers 48, 49 which only mix the low frequency components (i.e. <500 Hz) without significantly affecting the high frequency components. For low frequencies front mixer outputs correspond to sum of composite input signals and rear difference. The provision mixers is tantamount fixing coefficients f =b=0 l =r= 1 in decoder Specification 1,434,471. (Fig. 1). In Fig. 4, at capacitive impedances are mixing occurs via R12, R13 whereas higher path C12 provides an attenuating pass filter. level reduced by 6 dB produce a flat response R12 combination with output impedance decoder. circuit admits integration may alternatively be composed integrated differential amplifiers. Variable gain amplifiers performing function above consist gate-controlled FET (Q2, 2, not shown) shunting emitter current source (60) so that zero but RC limited. GB3603474A 1973-08-20 1974-08-15 Matrix four-channel decoding system Expired GB1447814A (en) Applications Claiming Priority (1) Application Number Priority Date Filing Date Title JP48093097A JPS5248001B2 1973-08-20 1973-08-20 Publications (1) Publication Number Publication Date GB1447814A true GB1447814A 1976-09-02 Family ID =14073006 Family Number Title Priority Date GB3603474A Expired GB1447814A 1973-08-20 1974-08-15 Matrix Country Status (4) Country Link US (1) US3934086A JP JPS5248001B2 DE DE2439863C2 GB Families Citing this family (19) * Cited examiner, † third party Publication number Priority date Publication date Assignee Title JPS5145503A * 1974-10-16 1976-04-19 Sansui Electric Co Matorikusu 4 channeruyodekooda JPS5154401A * 1974-11-07 1976-05-13 Sansui JPS5331601U * 1976-08-23 1978-03-18 US4704728A * 1984-12-31 1987-11-03 Peter Scheiber Signal re-distribution, processing accordance amplitude, phase, other characteristics US4799260A * 1985-03-07 1989-01-17 Dolby Laboratories Licensing Corporation Variable matrix US5046098A * 1985-03-07 1991-09-03 Dolby three channels US4862502A * 1988-01-06 1989-08-29 Lexicon, Inc. Sound reproduction JPH0228200U * 1988-08-12 1990-02-23 JP3006059B2 * 1990-09-17 2000-02-07 ソニー株式会社 Sound field expansion device ATE138238T1 * 1991-01-08 1996-06-15 Dolby Lab Corp ENCODER>Download PDF in English
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