Check whether the Pan3D volume is 0.<br>

If the Pan3D volume is 1, sounds are output from four speakers, namely, L, R, Ls, and Rs, for the directions specified by the Pan3D angle. In the initial state, the Pan3D angle is set to 1, and sounds are output from the L and R speakers.
By setting the Pan3D volume to 0, the Pan3D output can be stopped. By increasing the send of Center, sounds are output from the center speaker.