The setup: - **OS:** Win 10 19043.2364 - **Device:** Motherboard built-in audio `Advanced Micro Devices, Inc. [AMD] Starship/Matisse HD Audio Controller (prog-if 00 [HDA compatible])` (1022:1487) with 4 sets of earbuds plugged in - **DirectSound playback:** [dsound-surround.cpp](/uploads/d4f25206916069c14049b93a82b0c559/dsound-surround.cpp) - **Output testing:** recording with [Tenacity](https://tenacityaudio.org/) set to WASAPI and 8 channels, confirmed by listening to the buds output. I was going through channels in order (e.g. `dsound-surround.exe 2 0` then `dsound-surround.exe 2 1`). (7.1 channels in order for reference: `SPEAKER_FRONT_LEFT | SPEAKER_FRONT_RIGHT | SPEAKER_FRONT_CENTER |SPEAKER_LOW_FREQUENCY | SPEAKER_BACK_LEFT | SPEAKER_BACK_RIGHT | SPEAKER_SIDE_LEFT | SPEAKER_SIDE_RIGHT`) <details> <summary>SPEAKER_MONO</summary> {width=766 height=416} </details> <details> <summary>SPEAKER_STEREO</summary> {width=706 height=385} </details> <details> <summary>SPEAKER_2POINT1</summary> {width=900 height=310} </details> <details> <summary>SPEAKER_QUAD</summary> {width=900 height=282} </details> <details> <summary>SPEAKER_4POINT1</summary> {width=900 height=312} </details> <details> <summary>SPEAKER_5POINT1</summary> {width=900 height=279} </details> Looks like 7.1 is a superset of all of the above and it just uses the channels explicitly used by the format. E.g. `SPEAKER_MONO` is just `SPEAKER_FRONT_CENTER` so only it was playing anything. I'll revise the patches to reflect the above. -- https://gitlab.winehq.org/wine/wine/-/merge_requests/11154#note_145382