Patent ID: 8520862

Claim:
An audio system for enhancing localization of sound perceived by a listener in a listening position, the system comprising: two loudspeakers arranged distant from each other and from the listening position, where the sound is transmitted from each of the loudspeakers to the listening position according to a respective transfer function, and where the transfer functions have different phase responses over frequency; and a signal processing unit that is connected upstream of the loudspeakers and receives two electrical input signals to be radiated as respective sound signals by the two loudspeakers, where the signal processing unit includes a phase shifter unit that phase-shifts at least one of the electrical input signals such that a difference in phase responses is substantially constant over frequency in a frequency band audible to a human listener, where the phase shifter unit comprises at least one of an all-pass filter and two delay units, where one of the two delay units is supplied with one of the two electrical input signals, and where the other one of the two delay units is supplied with the other one of the two electrical input signals, where the phase shifter unit further comprises at least one all-pass filter that is supplied with one of the first and the second additional electrical signals, and provides an output signal; and where the phase shifter unit further comprises two summers, where one of the summers adds the output signal of the at least one all-pass filter and one of the two electrical input signals and outputs a first drive signal to one of the two loudspeakers, and where the other one of the summers adds the output signal of the at least one all-pass filter and the other one of the two electrical output signals and outputs a second drive signal to the other one of the two loudspeakers.