I know there are some media player programs that can output to multiple audio devices at the same time, but this is not a Windows default feature. Anybody happen to know a registry hack, a program or some version of Realtek drivers (motherboard integrated audio) that could enable it? Quick googling turns out programs that can redirect multiple inputs into all programs at the same time, but nothing to redirect everything into multiple outputs.
What I'm trying to do is get all sound output coming from rear panel line out, graphics card HDMI out and USB headphones at the same time. Of course I can't listen all at the same time, and I know I can change the default playback device between the three, but I want a situation where all three act like a "default playback device" at the same time so I don't have to change it manually depending on if I want PC audio out from headphones, speakers or TV.