单音轨的MPG文件原伴唱一般为左右声道，仅输出一个声道时喇叭响一边，此控件可将声音复制到另一边输出。属于dspack控件-Single track MPG files of the original accompaniment is usually left and right channels, and only output one channel speaker sound side, this control can copy the sound to the other side of