Touchdesigner + audio multichannel output For performance and stability reasons, it is not advisable to use multiple audio device output operators in 1 patch. That is why you mix your files before they are sent to the audio device output. Below are several examples. Example 1 There are 6 audio channels (speakers) in this audio out CHOP. With the merge you combine the sources. In this example I have 2 stereo files and 2 mono audio tones. 6 channels in total. You can also change the order in the merge if you want. when you want to direct 4 audio files to 4 seperate outputs you should work with mono files. Example 2 In this example 1 stereo file is played across all speakers. However, over speaker 5 and 6 there is a separate tone that can be activated with the keyboard buttons 1 and 2.   Tips for understanding audio in Touchdesigner:  https://forum.derivative.ca/t/how-to-play-several-audio-files-simultaneously-through-audiodevout/296965