Patent ID: 7231053

Claim:
An audio reproduction system comprising: a first audio input signal and a second audio input signal; a left main speaker and a right main speaker disposed respectively at left and right main speaker locations spaced along a speaker axis defined as a line passing through said left and right main speaker locations, with a listening area comprising the general area in front of the left and right main speaker locations such that the left main speaker location lies to the left and the right main speaker location lies to the right when viewed from the listening area, wherein said left and right main speakers reproduce sound associated with signals received by said left and right main speakers; a left sub-speaker and a right sub-speaker disposed respectively at left and right sub-speaker locations, wherein the left and right sub-speaker locations lie approximately on the speaker axis such that the left and right sub-speaker locations as viewed from the listening area are located to the left and right respectively of the respective left and right main speaker locations and are spaced a distance from the respective left and right main speaker locations such that the distance is in the range from approximately 50% to 150% of the average spacing between a person's ears as measured in a straight line through the head, wherein said left and right sub-speakers reproduce sound associated with signals received by them; and signal modification and combination means, wherein said signal modification and combination means comprises, means for modifying and transmitting the first audio input signal to said left main speaker, means for modifying and transmitting the second audio input signal to said right main speaker, means for subtracting a modified version of the second audio input signal from a modified version of the first audio input signal and transmitting the resulting difference signal to said left sub-speaker, and means for subtracting a modified version of the first audio input signal from a modified version of the second audio input signal and transmitting the resulting difference signal to said right sub-speaker, wherein said signal modification means includes a time delay applied to one of said first or second audio input signals relative to the other of said first and second audio input signals, wherein sound reproduced by the system that is associated with said first and second audio input signals is perceived by a listener located in the listening area whose head is oriented generally toward the speaker locations to originate from a broad range of sound locations extending beyond the locations of said left and right sub-speakers.