Sound control on OSMC

Hi,

I recently installed Spotify Connect Web on my Pi3, I’m able to control sound volume through PCM mixer.

$ amixer
Simple mixer control ‘PCM’,0
Capabilities: pvolume pswitch pswitch-joined
Playback channels: Front Left - Front Right
Limits: Playback 0 - 151
Mono:
Front Left: Playback 109 [72%] [-7.94dB] [on]
Front Right: Playback 109 [72%] [-7.94dB] [on]

I use Yaste to control OSMC, it have working sound volume buttons but they have no effect on the PCM volume, it is like another hidden mixer.

For example, if I listen Spotify at 80% (PCM), even if on OSMC the volume indicated is 100%, it will be 100% of the 80% of PCM. If I type amixer sset PCM -100%, I would have real 100%.

How can I use only one volume mixer for OSMC and Spotify ?

Thank you !

Yatse controls volume at a Kodi level, not via ALSA. This is because Kodi supports multiple sinks (Pulse, ALSA, PiSinkAudio)

Can I make Yatse controls ALSA ? Or synchronize both ?

If you aren’t using passthrough, you could select the bcm2835 ALSA device in Kodi. Then you can set audio via alsamixer, not Kodi.

Yatse cannot control audio volume in the way you would like unfortunately.

This probably doesn’t help but with yatse you also can control the volume of other devices via upnp.
There’s a upnp aplifier plugin for yatse. If you choose the hosts list click on 3 dot menu and choose edit.
Under advanced tab you will find it. Yatse will search for upnp devices which it’s volume it can control.
I found it by chance and was amazed about it! Now I can control the volume of my av receiver just with the volume rocker of my smarthone/tablet.

Thank you to all, at least I better understood how it works, and why I can’t manage to do what I want! My goal was to avoid to use command line and all, to make something simple but it’s hard to make it simple, mostly when you don’t really understand what you are doing!

Maybe it’s meaningless but is that possible to create another mixer for my USB sound card, and use it only for Spotify ? PCM will be everytime at 100% and I will be able to controls volume from 0% to 100% on Kodi and Spotify.