Totem (and GNOME in general) is moving in the direction of having less settings. Totem 3.6.x doesn't even have the Audio output setting. It simply uses the default gstreamer sink, which has to be changed through the command line or with dconf-editor (I made a post about that on ubuntuforums: http://ubuntuforums.org/showthread.php?t=2102513 ). I'm not sure how to make gstreamer downmix everything to mono (or if it's even possible). Something like downmixing is probably best handled through pulseaudio (see /etc/pulse/daemon.conf ).
Totem (and GNOME in general) is moving in the direction of having less settings. Totem 3.6.x doesn't even have the Audio output setting. It simply uses the default gstreamer sink, which has to be changed through the command line or with dconf-editor (I made a post about that on ubuntuforums: http:// ubuntuforums. org/showthread. php?t=2102513 ). I'm not sure how to make gstreamer downmix everything to mono (or if it's even possible). Something like downmixing is probably best handled through pulseaudio (see /etc/pulse/ daemon. conf ).