This sounds absolutely perfect. I think this is something many people could use for projects. Sometimes I think of something like an "operating system" which combines many tasks in one library, where you can add buttons which are already debounced, 7 Segments, Displays, Audio ^^ and so on ... like a simple LabView for Arduino
but I bought a DUE, because I thought there would be more libraries to handle this. But actually there are very little tutorials and libraries for the DUE available compared to the UNO.
But I think I have an idea to write my own program for playing two WAV files from the SD card.
The idea is to use this timer library https://github.com/ivanseidel/DueTimer
and create two timers that read the WAV (starting from byte 44) at the given sample rate and then write it to the DAC0 and DAC1. That should do everything I need.
But I'm still thinking about what happens if two timers are used. Will they called both one after the other with the given frequency? What if other Input interrupts (Buttons and Hall Sensors will also be used) are coming in?