Automatic Multichannel Simplification with Low Impacts on Sound Pressure at Ears

People hope to use minimum arrangement of loudspeakers to reproduce the experience of the film 3D sound at home. Although the Ando's conversion can convert n- to m-channel sound system by maintaining the sound pressure at the origin, it is time-consuming and expensive to use lots of subjective evaluations to distinguish the experience of spatial sound reproduced by m-loudspeaker arrangements. To solve this problem, we not only ensure the sound pressure at the origin invariably, but also limit the absolute error of sound pressure at ears to a given threshold or less while simplifying from n- to n-1-channel, and an automatic simplification algorithm from n- to m-channel sound system is proposed. The 22.2 multichannel sound system without two low-frequency effect channels as an example can be simplified to eight channels automatically and the total loudspeaker arrangements is 23. The subjective evaluation is comparable to that of the Ando's conversion and the cost of subjective evaluation is saved.