Last Updated: October 19, 2016
Yes, you can play two audio streams simultaneously: one via the HDMI, and a second via the 3.5mm audio or SPDIF using an .mp3 or .wav file.
Multiple audio files can also be played to the same audio output. In that case the audio files are mixed together.
Note: Files that are played simultaneously must all have the same audio sampling rate.
HD110, HD210, HD1010
You can play up to three audio streams to the USB expander at the same time. This can be three audio files, or one video plus two audio files.
You can play a separate audio file to each of the three analog outputs, while also playing audio to the HDMI/SPDIF output.