[LAU] Trying to get 8 channel sound from Linux Mint and an Intel NUC

[Max]

On 26.09.19 06:05, Scott wrote:
> I am trying to get software control of 8 channels of audio over HDMI. I 
> don't know very much about linux audio software and naively assumed I'd 
> plug an HDMI into an audio converter/splitter and get 8 working outputs. 
> What I get is silence. Someone here must understand this and I'd 
> appreciate help!
> 

> alsamixer shows Auto-Mute Disabled, Loopback Enabled.
> Master, Headphones, Speaker and PCM all have columns in the white (but a green 00 at the bottom). There's no line, front, center, side, rear, etc. There are 5 S/PDIF columns, all blank and showing 00, and I can't get them to change (but presumably I don't care.)

Are you sure you have the right card selected if you want the HDMI 
output? My machine shows 'Intel PCM' and 'Intel HDMI' separately.
In Alsamixer, select soundcard with F6