Created attachment 305028 [details] alsa-info from system Subwofer and back/right channel are swapped with Asus Strix Raid DLX soundcard. It seems that sub-woofer Mixer control only mute/unmute the channel. Changing the volume for the sub-woofer works only with back/right mixer control. That means you can use a 2.1 speaker setup only with a 5.1 or 7.1 mixer control setup. It looks like a channel routing problem but sorry i don't know to do that with alsa. Not sure if this is a kernel issue or related to alsa directly. I am happy to provide more information if requested.
Any news on that? I am happy to provide more information.