非中心倾听位置的立体声像分析

Analysis on stereophonic sound image for an off-center listener

对非中心倾听位置的立体声像进行了理论和实验分析。结果表明,非中心倾听位置的声像定位结果和信号的频率有关。当倾听者偏离中心位置超过一定距离Xmax或信号频率超过某一上限fmax时,就有可能出现声像位置超出扬声器布置之外,从而破坏立体声的空间信息的情况。而Xmax和fmax是互成反比关系。缩小左右扬声器之间的张角或增加中置扬声器(如5.1通路系统)可扩大听音区域,提高声像的稳定性。

The stereophonic sound image for an off-center listener is analysed theoretically and experimentally. The results show that, the sound image direction for an off-center listener depends on frequency. When listener departs from center position to some distance xmax or the frequency of signal is higher than a limit fmax, the sound image may locate outside the arrangement of the stereophonic loudspeaker pair. Therefore the spatial information of stereo is spoiled. It is also proved that xmax is inversely proportional to fmax, or conversely. A narrow span of loudspeaker pair or adding a front loudspeaker (as in 5.1 ch system) can enlarge listening area and stabilize sound image.