[xubuntu-users] HDMI playback only good when pavucontrol is running....

[vermontpoet]

Okay, I've made my life unnecessarily complicated by running Xubuntu on 
an ARM processor (cubox-i4), but not all my problems may be related to 
that. I'm having fun. Here's my first conundrum: Sound works, but it 
sounds bad (like bad sampling), unless I invoke the Pulse Audio Volume 
Control app (Sound Settings). Soon as I do that, the sound is crystal 
clear. Instantly. So, there must be a setting somewhere? I've been 
Googling this quite a bit, but haven't gotten any good leads (or am 
using the wrong search terms).

Device - imx-hdmi-soc / Analog Stereo Output

So, the sound goes to a jack on the back of the HDMI monitor.