Patent ID: 6970567

Claim:
A method of deriving one of a plurality of output audio signals from two input audio signals S 1 (Î±) and S 2 (Î±), the output audio signal associated with a principal direction Î²2, the input audio signals encoded with an audio source signal having a direction Î±, comprising generating two antidominant audio signals of the form: antidominant Î² 1 (Î±)= AS 1 Î² 1 Â·S 1 (Î±)+ AS 2 Î² 1 Â·S 2 (Î±) and antidominantÎ² 3 (Î±)= AS 1 Î² 3 Â·S 1 (Î±)+ AS 2 Î² 3 Â·S 2 (Î²), wherein in one antidominant signal the angle Î² 1 is the angle of one of the two principal directions adjacent to the principal direction Î² 2 of the output audio signal and in the other antidominant signal the angle Î² 3 is the angle of the other of the two principal directions adjacent to the principal direction Î² 2 of the output audio signal, and wherein the coefficients AS 1 Î² 1 and AS 2 Î² 1 are selected so that the one antidominant signal is substantially zero when Î± is Î² 1 and the coefficients AS 1 Î² 3 and AS 2 Î² 3 are selected so that the other antidominant signal is substantially zero when Î± is Î² 3 , applying amplitude control to the two antidominant signals to deliver a pair of signals having substantially equal magnitudes, and additively or subtractively combining the amplitude controlled antidominant audio signals to provide the output audio signal.