In a configuration with 3 output devices in Windows (8.1), I'd like to be able to link all 3 devices together so they play the same audio streams out each output simultaneously.
The stereo mix component that is hidden by default in the recording section accomplishes this for 1 additional output, but I think it also introduces a lag as it has to first listen and then play but I may be wrong there. Using my default speakers and a headset, I heard the speaker output before I heard the same sound on the headset.