Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
468 words
A sound system for utilizing a pair of quadrature-encoded composite stereo signals E1 and E2, with E1 comprising an RF component plus both RB and LB components and E2 comprising an LF component plus both RB and LB components, where LF, RF, LB and RB are discrete left front, right front, left back and right back quadraphonic audio signals, respectively, and where the resultant vector of the back signal components of E1 is either in phase or 180* out of phase with the resultant vector of the back signal components of E2, to provide a quadraphonic sound rendition from four sound speakers in a left front, right front, left back and right back room orientation, in which said left back speaker and said right back speaker each include a voice coil comprising a pair of input terminals with one terminal of each said pair connected to a common junction, comprising: a pair of audio amplifiers individually translating an assigned one of said composite signals; a passive 90* symmetrical phase-shifting lattice network coupled to one of said audio amplifiers for shifting the phase of a first of said composite signals and having a pair of output terminals; a passive 180* symmetrical phase-shifting lattice network coupled to the other of said audio amplifiers for shifting the phase of a second of said composite signals and also having a pair of output terminals; means for directly coupling one of said audio amplifiers to said left front sound speaker for applying said first composite signal thereto, and means for directly coupling the other audio amplifier to said right front sound speaker for applying said second composite signal thereto; a transformer comprising a primary winding having a pair of input terminals and a secondary winding having a pair of output terminals and a reference terminal intermediate said secondary output terminals; means for coupling the output terminals of said 90* phase shifting network across the input terminals of said primary winding; means for coupling the output terminals of said secondary winding across the free input terminals of said voice coils; and means for coupling one output terminal of said 180* phase shifting network to said reference terminal of said secondary winding and for coupling the other output terminal of said 180* phase shifting network to said common junction of said voice coils, whereby said coupling of said phase-shifting networks to said transformer additively and subtractively combine the phaseshifted composite signals to obtain a pair of resultant signals E3 and E4, E3 comprising a LF, RF and RB component but free of any LB component and E4 comprising a LF, RF and LB component but free of any RB component, and means for applying said resultant signal E3 to the right back sound speaker and said resultant signal E4 to the left back sound speaker.
Claim 2
Dependent Claim
468 words
A sound system for utilizing a pair of quadrature-encoded composite stereo signals E1 and E2, with E1 comprising an RF component plus both RB and LB components and E2 comprising an LF component plus both RB and LB components, where LF, RF, LB and RB are discrete left front, right front, left back and right back quadraphonic audio signals, respectively, and where the resultant vector of the back signal components of E1 is either in phase or 180* out of phase with the resultant vector of the back signal components of E2, to provide a quadraphonic sound rendition from four sound speakers in a left front, right front, left back and right back room orientation, in which said left back speaker and said right back speaker each include a voice coil comprising a pair of input terminals with one terminal of each said pair connected to a common junction, comprising: a pair of audio amplifiers individually translating an assigned one of said composite signals; a passive 90* symmetrical phase-shifting lattice network coupled to one of said audio amplifiers for shifting the phase of a first of said composite signals and having a pair of output terminals; a passive 180* symmetrical phase-shifting lattice network coupled to the other of said audio amplifiers for shifting the phase of a second of said composite signals and also having a pair of output terminals; means for directly coupling one of said audio amplifiers to said left front sound speaker for applying said first composite signal thereto, and means for directly coupling the other audio amplifier to said right front sound speaker for applying said second composite signal thereto; a transformer comprising a primary winding having a pair of input terminals and a secondary winding having a pair of output terminals and a reference terminal intermediate said secondary output terminals; means for coupling the output terminals of said 90* phase shifting network across the input terminals of said primary winding; means for coupling the output terminals of said secondary winding across the free input terminals of said voice coils; and means for coupling one output terminal of said 180* phase shifting network to said reference terminal of said secondary winding and for coupling the other output terminal of said 180* phase shifting network to said common junction of said voice coils, whereby said coupling of said phase-shifting networks to said transformer additively and subtractively combine the phaseshifted composite signals to obtain a pair of resultant signals E3 and E4, E3 comprising a LF, RF and RB component but free of any LB component and E4 comprising a LF, RF and LB component but free of any RB component, and means for applying said resultant signal E3 to the right back sound speaker and said resultant signal E4 to the left back sound speaker.
Claim 3
Dependent Claim
43 words
A quadraphonic sound system in accordance with claim 1, wherein the E1 composite signal is defined as E1 RF + j 0.707 RB - 0.707 LB and the E2 composite signal is defined as E2 LF - j 0.707 LB + 0.707 RB.
Claim 4
Dependent Claim
65 words
A quadraphonic sound system in accordance with claim 2, wherein the component values of said phase-shifting networks are Such that a phase differential of approximately 90* exists between the phase shift vs. frequency curves of the 90* and 180* phase-shifting networks throughout substantially the entire audio passband, thus substantially eliminating LB cross-talk in said right back speaker and RB cross-talk in said left back speaker.