US3632886A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Quadrasonic sound system
Assignee: Individual
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Filing: 1969-12-29
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Granted: 1972-01-04
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Expires: 1989-12-29
Abstract
Abstract A stereophonic sound system is disclosed utilizing a two-channel transmission path yet capable of locating virtual sound sources at any point on a circle around a listener. The two-channel transmission path may consist of conventional stereophonic channels such as records, tapes, broadcasting channels, etc. The recording or transmitting means (as the case may be) of the invention provides two audio signals which may comprise preselected combinations of four (for example) directional inputs. One channel may include the first input plus a signal proportional to the sum of the second and fourth inputs, while the second channel consists of the third input plus a signal proportional to the difference between the second and fourth inputs. The sound reproducing means couples these signals and various combinations thereof to four (for example) loudspeakers which may be arranged on the circumference of a circle around the listener. The first speaker may be responsive to the signal on one channel, the next adjacent speaker is responsive to the sum of the signals on the two channels, the third successive speaker is responsive to the second channel, and the last speaker is responsive to the difference between the signals on the two channels. Means are disclosed for controlling the gain in the signal paths of the voltages coupled to the various speakers relative to the other speakers to increase the audio separation between adjacent speakers and thus enhance the directional effect.
Inventors
- 👤 Peter Scheiber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 10:12
CPC Classifications
H; H04; H04S; H04S3/00; H04S3/02
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
165 words
For use with a stereophonic sound system wherein a receiver means couples audio data to at least four separate speakers and wherein audio signals are transmitted to said receiver means on only two channels A and B, a recording or transmitting network, comprising means for coupling a first signal desired to be coupled to a first speaker to at least one of said channels with a preselected amplitude and polarity, means for coupling a second signal desired to be coupled to a second speaker to at least the other of said channels with a preselected amplitude and polarity, means for coupling a third signal desired to be coupled to a third speaker to both A and B channels with the same polarity in both channels and preselected amplitudes in said channels, and means for coupling a fourth signal desired to be coupled to a fourth speaker to both A and B channels with opposite polarities in the two channels and preselected amplitudes in said channels.
Claim 2
Dependent Claim
165 words
For use with a stereophonic sound system wherein a receiver means couples audio data to at least four separate speakers and wherein audio signals are transmitted to said receiver means on only two channels A and B, a recording or transmitting network, comprising means for coupling a first signal desired to be coupled to a first speaker to at least one of said channels with a preselected amplitude and polarity, means for coupling a second signal desired to be coupled to a second speaker to at least the other of said channels with a preselected amplitude and polarity, means for coupling a third signal desired to be coupled to a third speaker to both A and B channels with the same polarity in both channels and preselected amplitudes in said channels, and means for coupling a fourth signal desired to be coupled to a fourth speaker to both A and B channels with opposite polarities in the two channels and preselected amplitudes in said channels.
Claim 3
Dependent Claim
36 words
A recording or transmitting network according to claim 1, further including means for reducing the amplitude of said third and fourth signals relative to said first and second signals, respectively, in said A and B channels.
Claim 4
Dependent Claim
28 words
A recording or transmitting network according to claim 2, wherein said amplitude reducing means reduces the amplitude of said third and fourth signals by substantially the same amount.
Claim 5
Dependent Claim
29 words
A recording or transmitting network according to claim 3, wherein said amplitude reducing means reduces the amplitude of said third and fourth signals by a factor of approximately 0.707.
Claim 6
Dependent Claim
41 words
A recording or transmitting network according to claim 1, including means for superimposing a control tone on at least one of said channels, said control signal being dependent upon the relative signal strengths of said first, second, third and fourth signals.
Claim 7
Dependent Claim
52 words
A recording or transmitting network according to claim 5, including means for superimposing a control tone on each of said A and B channels, each of said control tones being dependent upon the ratio of the total signal power in two of the channels to the total power in all four channels.
Claim 8
Dependent Claim
181 words
For use with a stereophonic sound system wherein a receiver means couples audio data to at least four separate speakers and wherein audio signals are transmitted to said receiver means on two channels A and B, a recording or transmitting network, comprising: at least four acoustical-electrical transducer means for producing, respectively, at least four audio signals to be transmitted, means for coupling a first signal desired to be coupled to a first speaker to at least one of said channels with a preselected amplitude and polarity, means for coupling a second signal desired to be coupled to a second speaker to at least the other of said channels with a preselected amplitude and polarity, means for coupling a third signal desired to be coupled to a third speaker to both A and B channels with the same polarity in both channels and preselected amplitudes in said channels, and means for coupling a fourth signal desired to be coupled to a fourth speaker to both A and B channels with opposite polarities in the two channels and preselected amplitudes in said channels.
Claim 9
Dependent Claim
181 words
For use with a stereophonic sound system wherein a receiver means couples audio data to at least four separate speakers and wherein audio signals are transmitted to said receiver means on two channels A and B, a recording or transmitting network, comprising: at least four acoustical-electrical transducer means for producing, respectively, at least four audio signals to be transmitted, means for coupling a first signal desired to be coupled to a first speaker to at least one of said channels with a preselected amplitude and polarity, means for coupling a second signal desired to be coupled to a second speaker to at least the other of said channels with a preselected amplitude and polarity, means for coupling a third signal desired to be coupled to a third speaker to both A and B channels with the same polarity in both channels and preselected amplitudes in said channels, and means for coupling a fourth signal desired to be coupled to a fourth speaker to both A and B channels with opposite polarities in the two channels and preselected amplitudes in said channels.
Claim 10
Dependent Claim
140 words
For use in a sound reproducing system capable of locating virtual sound sources at essentially any point on a circle surrounding a listener position, wherein audio information corresponding to four separate directional inputs is transmitted on a two-channel transmission path and wherein there are provided at least four loudspeakers adapted to be arranged around a listener, the combination comprising: means for coupling the signal on at least one of said channels to a first of said speakers, means for coupling the signals on said first and second channels to a second speaker with the same polarity and a preselected amplitude relationship, means for coupling the signal on at least the second of said channels to a third speaker, and means for coupling the signals on said two channels to a fourth speaker with opposite polarities and a preselected amplitude relationship.
Claim 11
Dependent Claim
140 words
For use in a sound reproducing system capable of locating virtual sound sources at essentially any point on a circle surrounding a listener position, wherein audio information corresponding to four separate directional inputs is transmitted on a two-channel transmission path and wherein there are provided at least four loudspeakers adapted to be arranged around a listener, the combination comprising: means for coupling the signal on at least one of said channels to a first of said speakers, means for coupling the signals on said first and second channels to a second speaker with the same polarity and a preselected amplitude relationship, means for coupling the signal on at least the second of said channels to a third speaker, and means for coupling the signals on said two channels to a fourth speaker with opposite polarities and a preselected amplitude relationship.
Claim 12
Dependent Claim
25 words
The combination according to claim 8, wherein said first and third speakers define a diagonal intersecting a diagonal defined by said second and fourth speakers.
Claim 13
Dependent Claim
31 words
The combination according to claim 8, wherein the signals fed to said second and fourth speakers are reduced in amplitude relative to the signals coupled to the first and third speakers.
Claim 14
Dependent Claim
180 words
For use in a sound reproducing system capable of locating virtual sound sources at essentially any point on a circle surrounding a listener position, wherein audio information corresponding to four separate directional inputs is transmitted on a two-channel transmission path and wherein there are provided at least four loudspeakers adapted to be arranged around a listener, the combination comprising: means for coupling a signal on at least one of said channels to a first of said speakers, means for coupling the signal on at least the second of said channels to a third speaker, means for coupling the signals on said first and second channels to a second speaker with the same polarity and with their amplitudes reduced by a factor of approximately 0.707 relative to the amplitude of the signals coupled to said first and third speakers, and means for coupling the signals on said two channels to a fourth speaker with opposite polarities and with their amplitudes reduced by a factor of approximately 0.707 relative to the amplitude of the signals coupled to said first and third speakers.
Claim 15
Dependent Claim
180 words
For use in a sound reproducing system capable of locating virtual sound sources at essentially any point on a circle surrounding a listener position, wherein audio information corresponding to four separate directional inputs is transmitted on a two-channel transmission path and wherein there are provided at least four loudspeakers adapted to be arranged around a listener, the combination comprising: means for coupling a signal on at least one of said channels to a first of said speakers, means for coupling the signal on at least the second of said channels to a third speaker, means for coupling the signals on said first and second channels to a second speaker with the same polarity and with their amplitudes reduced by a factor of approximately 0.707 relative to the amplitude of the signals coupled to said first and third speakers, and means for coupling the signals on said two channels to a fourth speaker with opposite polarities and with their amplitudes reduced by a factor of approximately 0.707 relative to the amplitude of the signals coupled to said first and third speakers.
Claim 16
Dependent Claim
42 words
The combination according to claim 10, wherein each of said coupling means includes variable gain amplifier means, said combination further including gain control means for varying the gain of said variable gain amplifier means so as to increase separation between adjacent speakers.
Claim 17
Dependent Claim
44 words
The combination according to claim 12, wherein the gains of the variable gain amplifier means associated with the first and third speakers are maintained equal and the gains of the variable gain amplifier means associated with said second and fourth speakers are maintained equal.
Claim 18
Dependent Claim
40 words
The combination according to claim 12, wherein said gain control means includes means for computing the instantaneous value of the ratio of the signal amplitude in one of said channels to the signal amplitude in the other of said channels.
Claim 19
Dependent Claim
23 words
The combination according to claim 12, wherein said gain control means comprises means for comparing the envelopes of the signals in said channels.
Claim 20
Dependent Claim
87 words
The combination according to claim 13, wherein the gain of said variable gain amplifiers associated with said first and third speakers is minimum and the gain associated with said second and fourth speakers is maximum when said ratio is equal to one, and wherein the gain of the variable gain amplifiers associated with said first and third speakers is a maximum and the gain of the amplifiers associated with said second and fourth speakers a minimum when there is no signal in either one of said channels.
Claim 21
Dependent Claim
35 words
The combination according to claim 16, wherein said gain control means varies the gain of said variable gain amplifiers so as to maintain the total power coupled to said speakers at a substantially constant level.
Claim 22
Dependent Claim
25 words
The combination according to claim 12, wherein said gain control means includes means responsive to a modulated tone on At least one of said channels.
Claim 23
Dependent Claim
23 words
The combination according to claim 12, wherein said gain control means includes means responsive to modulated control tones on each of said channels.
Claim 24
Dependent Claim
84 words
The combination according to claim 12, including further variable gain amplifier means and gain control means, said further gain control means adapted to control the gain of said further variable gain amplifiers and responsive to voltages dependent upon (a) the power differential between the inputs and outputs of the first-named variable gain amplifiers associated with the first and third speakers and (b) the power differential between the inputs and outputs of the first named variable gain amplifiers associated with the second and fourth speakers.
Claim 25
Dependent Claim
190 words
A stereophonic sound system wherein audio signals are transmitted on only two channels A and B, in combination, an encoder and a decoder, said encoder comprising means for coupling a first signal desired to be coupled to a first speaker to at least the A channel, means for coupling a second signal desired to be coupled to a second speaker to at least the B channel, means for coupling a third signal desired to be coupled to a third speaker to both A and B channels with the same polarity in both channels, and means for coupling a fourth signal desired to be coupled to a fourth speaker to both A and B channels with opposite polarity in both channels, said decoder comprising means for coupling the signal on one of said channels to a first of said speakers, means for coupling the signals on said first and second channels to a second speaker with the same polarity, means for coupling the signal on the second of said channels to a third speaker, and means for coupling the signals on said two channels to a fourth speaker with opposite polarities.
Claim 26
Dependent Claim
190 words
A stereophonic sound system wherein audio signals are transmitted on only two channels A and B, in combination, an encoder and a decoder, said encoder comprising means for coupling a first signal desired to be coupled to a first speaker to at least the A channel, means for coupling a second signal desired to be coupled to a second speaker to at least the B channel, means for coupling a third signal desired to be coupled to a third speaker to both A and B channels with the same polarity in both channels, and means for coupling a fourth signal desired to be coupled to a fourth speaker to both A and B channels with opposite polarity in both channels, said decoder comprising means for coupling the signal on one of said channels to a first of said speakers, means for coupling the signals on said first and second channels to a second speaker with the same polarity, means for coupling the signal on the second of said channels to a third speaker, and means for coupling the signals on said two channels to a fourth speaker with opposite polarities.
Claim 27
Independent Claim
96 words
A method of recording or transmitting at least four directional audio information signals on two channels comprising forming at least two composite signals each of which includes at least three of said audio information signals in preselected amplitude and phase relationships, at least one of said audio information signals having a different phase in each of said composite signals, said amplitude and phase relationships being such that four combinations of said two composite signals with preselected phase and amplitude relationships will yield four separate signals in which respective ones of said four directional signals are predominant.
Claim 28
Independent Claim
96 words
A method of recording or transmitting at least four directional audio information signals on two channels comprising forming at least two composite signals each of which includes at least three of said audio information signals in preselected amplitude and phase relationships, at least one of said audio information signals having a different phase in each of said composite signals, said amplitude and phase relationships being such that four combinations of said two composite signals with preselected phase and amplitude relationships will yield four separate signals in which respective ones of said four directional signals are predominant.
Claim 29
Dependent Claim
55 words
A method of recording or transmitting at least four directional audio information signals according to claim 22, wherein at least one of said audio information signals has the same relative phase in each of said composite signals and at least one of said audio information signals has opposite phase in each of said composite signals.
Claim 30
Dependent Claim
33 words
A method of recording or transmitting at least four directional audio information signals according to claim 22, wherein at least some of said phase relationships are equal to a phase difference of 180*.
Claim 31
Independent Claim
131 words
A method of substantially reproducing at least four individual directional audio information signals which are contained in two information channels, wherein the signal in each of said channels comprises a combination of at least three of said directional signals with preselected phase and amplitude relationships, comprising deriving said four output signals from the signals in said two channels, at least one pair of said output signals being derived by combining the signals in said channels with preselected phase and amplitude relationships wherein different phase relationships are used to derive each signal of said pair of signals, the remaining output signals, if any, being derived from the signals in one of said channels, whereby a different desired one of said four directional signals is predominant in each of said four output signals.
Claim 32
Independent Claim
131 words
A method of substantially reproducing at least four individual directional audio information signals which are contained in two information channels, wherein the signal in each of said channels comprises a combination of at least three of said directional signals with preselected phase and amplitude relationships, comprising deriving said four output signals from the signals in said two channels, at least one pair of said output signals being derived by combining the signals in said channels with preselected phase and amplitude relationships wherein different phase relationships are used to derive each signal of said pair of signals, the remaining output signals, if any, being derived from the signals in one of said channels, whereby a different desired one of said four directional signals is predominant in each of said four output signals.
Claim 33
Dependent Claim
46 words
A method of substantially reproducing at least four individual directional audIo information signals according to claim 25, further including the step of controlling the gain of at least some of said four output signals depending on a preselected comparison of the signals in said two channels.
Claim 34
Dependent Claim
75 words
A method of substantially reproducing at least four individual directional audio information signals according to claim 25, wherein at least one of said output signals is derived by combining the signals in said two channels with a zero phase shift and at least one other of said four output signals is derived by combining said signals in said two channels with one of said signals in said two channels being shifted in phase by 180*.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-03 | 1975-07-05 | 1976-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-03 | 1979-07-05 | 1980-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |