I have the Audient iD14 audio interface. There are four input channels on it, and because of this pulseaudio thinks it's a 4.0 surround sound system when it's not. When playing audio, it is very unbalanced to the right. Bringing the balance slider to the left helps, but I think there's still phasing issues going on. Also, the balance is off again when I use Jack. Is there anyway I can fix this? I tried setting "enable-remixing = no" inside of "/etc/pulse/daemon.conf" and uncommented it, but that didn't work.
Just had this sort of problem as well (I'm on 16.04 by the way): Pulseaudio did an unwanted upmix on me and /etc/pulse/daemon.conf was ignored. However, it seems that the configuration file in the user's home directory is not ignored. After adding "enable-remixing = no" to ~/.pulse/daemon.conf and restarting pulseaudio, I got the stereo output I was actually playing back.