Matching Projection Decoding Method for Ambisonics System

The basic Ambisonics decoding method will break down when the playback loudspeakers distribute unevenly. This paper proposes a modified Ambisonics method, the matching projection decoding method, for solving this problem. The matching projection decoding method is a kind of the greedy algorithm. It firstly calculates the projection value of the object Ambisonics signal over each Ambisonics signal of loudspeakers, then the maximum projection value is assigned to the corresponding loudspeaker. This process is repeated until all the loudspeakers have been assigned a gain value. The objective and subjective experiments were performed to evaluate the proposed system and the basic system. Objective evaluation results show that the accuracy of the sound field generated by the matching projection decoding method is better than that of the basic method; and the subjective evaluation results show a more correct directional perception of the matching projection decoding method than the basic one.