In LAV filters there is an option to Normailze Matrix which globally attenuates volume.  This makes for a good "night mode" option when I don't want to wake the family.  There isn't an option for this in Emby Theater, but if I go into the directshowplayer.xml file and turn on the LAV tray icons, I can enable the option.  However, the option does not persist through updates so I have to repeat the process.  It would be nice to have a persistent setting for this in ET.