Patent ID: 7330552

Claim:
A method of creating at least three channels of audio output data from a left input channel of audio data and a right input channel of audio data comprising the steps of: (a) converting the left input channel data from the time domain to a plurality of left frequency components in the frequency domain; (b) converting the right input channel data from the time domain to a plurality of right frequency components in the frequency domain; (c) establishing at least two channels for audio data output and assigning each channel a center position angle; (d) determining the position angle of in phase phantom images in each frequency component and rounding to the nearest channel position angle; (e) identifying out-of-phase data from the left and right frequency components; (f) generating data for at least one forward left output channel and at least one forward right output channel; (g) generating data for at least one additional output channel from the out-of-phase data; (h) optimizing channel output versus position response for the data for each output channel; (i) adjusting the output channel data magnitudes to equal the input channel magnitudes; (j) converting the output channel data from the frequency domain to the time domain for each of the at least three channels, thereby producing audio output data for each of said channels.