From the ring menu: [System] > [Volume] > [Max Volume Limiter], you can apply a volume limitation on all sound output from VirtualCast EXCEPT the voice chat. This feature is useful to prevent unexpected loud sounds played from niconico video player and VCIs containing sound.
The default value is 100, which means the volume limitation is disabled. * By moving the slider to the left, the limit (or threshold) of the loudest sound allowed will be lowered. When the output level exceeds the set value, the master volume of VirtualCast will be lowered temporarily.
* To be exact, a limiter is applied with its threshold set to 0db.