They are a bit tight, I mean, they make money with those boards. Interesting that it works different compared to your DSP board.
So I think the driver just provides an input device at the /dev folder. The mixing part is on Kodi then (I was wrong). Install the "Kodi Audio Mixer" add-on. Hopefully that add-on will grab your input device from /dev folder, and mixes everything together.
Did that, and got a mixer with about 24 channels with no names, which seemed to all be muted, so I unmuted them all and turned up their volumes. Didn´t do the trick unfortunately 
And sadly, addons cannot be played around with via chorus2, so I had to connect the libreelec directly to the monitor although installing the addon vas done easily with ssh.
PS: Just tried installing Kodi Audio Mixer on the machine with the DSP board, connected to my TV, and there I get a completely empty pop up with no controls at all.
PPS: Prolly not supposed to work with hifiberry Kodi Audio Mixer has an empty window!!?
Crazy. Does the amixer command show something on SSH?
Hey jazzl!
What happens if you do this on SSH: amixer -c 0 set Digital 80%?
This line has been taken from the official HiFiBerry doc, so it's actually common knowledge for all HiFiBerry users.
Thanks, it will take a while till I try that one out, as I no longer have the libreelec sdcard in the pi I was trying on. I must be the only hifiberry user who didn´t thoroughly read through the official Hifiberry doc then 
