Split phase stereophonic sound synthesizer

In a system which reproduces correlated sound and visual information, including a source of correlated monophonic sound and visual signals;

• means, coupled to said signal source and including a video reproduction medium, for displaying visual information derived from said visual signals;
• a synthetic stereo sound system comprising:
• a phase splitter circuit having an input coupled to said signal source for receiving said monophonic sound signals and first and second outputs at which monophonic sound signals of opposite phase relationship are produced;
• a transfer function circuit having an input coupled to said first output of said phase splitter circuit and an output, and exhibiting an amplitude versus frequency response characteristic including two spaced frequencies of maximum attenuation and a frequency of minimum attenuation intermediate said spaced frequencies within an audio frequency range occupied by said monophonic sound signals, for producing an intensity modulated signal at said transfer function circuit output;
• a first output terminal responsive to said output of said transfer function circuit for producing a first synthesized stereo sound signal;
• a second output terminal;
• means for transferring monophonic sound signals from said second output of said phase splitter circuit to said second output terminal without introduction of variations in amplitude or phase with frequency over said audio frequency range;
• means for transferring intensity modulated signals from said output of said transfer function circuit to said second output terminal without further introduction of variations in amplitude or phase with frequency over said audio frequency range to develop a second synthesized stereo sound signal;
• first and second loudspeakers located at respective opposite sides of said visual information display means;
• and
• means for coupling said first and second output terminals to said first and second loudspeakers, respectively, for producing a synthetic stereo sound field about said visual information display means.

A television sound and image reproduction system, including a source of television sound and video signals;

• a television receiver enclosure, a kinescope mounted in said enclosure for reproducing video information;
• and means responsive to said video signals for applying video information to said kinescope for reproduction;
• said reproduction system also including a synthetic stereo sound system comprising:
• a phase splitter circuit having an input coupled to said signal source for receiving said television sound signals and first and second outputs at which television sound signals of opposite phase relationship are produced;
• a transfer function circuit having an input coupled to said first output of said phase splitter circuit and an output, and exhibiting an amplitude versus frequency response characteristic including two spaced frequencies of maximum attenuation and a frequency of minimum attenuation intermediate said spaced frequencies within an audio frequency range occupied by said television sound signals, for producing an intensity modulated signal at said transfer function circuit output;
• a first output terminal responsive to said output of said transfer function circuit for producing a first synthesized stereo sound signal;
• a second output terminal;
• means for transferring television sound signals from said second output of said phase splitter circuit to said second output terminal without introduction of variations in amplitude or phase with frequency over said audio frequency range;
• means for transferring intensity modulated signals from said output of said transfer function circuit to said second output terminal without further introduction of variations in amplitude or phase with frequency over said audio frequency range to develop a second synthesized stereo sound signal;
• an amplifier located external to said enclosure, and including first and second amplifying channels having respective inputs coupled to said first and second output terminals, and respective first and second outputs;
• first and second loudspeakers located external to said enclosure and subject to being placed by a user at positions on opposite sides of said enclosure, and respectively coupled to said first and second outputs of said amplifier channels for reproducing said first and second synthesized stereo sound signals to develop a synthetic stereo sound field.