Patent ID: 7864631

Claim:
A method of determining the distance (d 12 ) between two loudspeakers (L 1 , L 2 ), the method comprising: providing a test signal (N), wherein the test signal (N) comprises white noise in which all frequencies of the white noise are equally represented; combining the test signal (N) with a sound signal (S) to give a combined signal (S N ) in which the test signal is imperceptible to a listener; issuing the combined signal (S N ) by means of a first loudspeaker (L 1 ); detecting the combined signal (S N ) by a detecting means (M 2 ) associated with the second loudspeaker (L 2 ); processing the detected combined signal (Z) to obtain an acoustic impulse response (IR), wherein processing the detected combined signal (Z) comprises accumulating the received combined signal to increase a ratio of the test signal contribution to the host signal by sampling and storing the detected combined signal in a buffer with the same length as a period of repetition of a test sequence of the test signal; and using the acoustic impulse response (IR) to determine the distance (d 1,2 ) between the first loudspeaker (L 1 ) and the second loudspeaker (L 2 ).