Room compensation in wave field synthesis by means of multichannel inversion

In the reproduction of sound using loudspeakers, the listening room adds echoes not considered by the reproduction system deteriorating the rendered acoustic field. Wave field synthesis is a 3D audio reproduction system, which allows synthesizing a realistic sound field in a wide area by using a large number of loudspeakers arrays. This paper proposes a room compensation approach based on a multichannel inverse filter bank that corrects the room effects at selected points within the listening area. Points are selected in order to allow a huge sweet spot disregarding the quality of the room. As a difference with previous works, this approach solves directly the multiple-input/multiple-output inverse system without simplifications, thus obtaining the best bank of inverse filters for the room to be compensated. Efficient mathematical algorithms to make affordable the computation of this filter bank are proposed. A carefully developed laboratory experiment to validate the method is also reported. Finally, an evaluation of the computational power required to run the filter bank in real time is presented.