Patent ID: 9591420
Date: 2017-03-07
CPC Classifications: H04M,H04R,H04S

Claim:
1. A sound reproduction system providing at least four separate sound zones in one coherent listening room, the system comprising: an audio source having at least four output channels and providing an audio source signal for each output channel, each audio channel being associated with one sound zone; at least four planar loudspeakers having a directional characteristic, wherein each audio channel is associated with one loudspeaker and each loudspeaker is associated with one sound zone, and each loudspeaker is supplied with a respective loudspeaker signal and radiates a corresponding acoustic signal; a first multi-channel digital filter that receives the audio source signals of audio channels associated with sound zones in a front portion of a car cabin and provides the respective loudspeaker signals for the loudspeakers associated with the sound zones in the front portion of the car cabin, a transfer characteristic of the first digital filter being characterized by a first transfer matrix, a second multi-channel digital filter that receives the audio source signals of audio channels associated with sound zones in a rear portion of a car cabin and provides the respective loudspeaker signals for the loudspeakers associated with the sound zones in the rear portion of the car cabin, a transfer characteristic of the second digital filter being characterized by a second transfer matrix; wherein the acoustic signals radiated by the planar loudspeakers superpose to a resulting acoustic signal in each sound zone, and wherein each transfer matrix represents the inverse of a room impulse response (RIR) matrix that includes transfer functions representing the RIR, causing, in each of the at least four separate sound zones, the resulting acoustic signal to substantially correspond to the audio source signal associated with the same sound zone, and causing contributions of audio source signals associated with a different sound zone to the resulting acoustic signal to be reduced.