The share of voice mixer mode is available for Dise One players. When using share of voice, playlists are set to play by a percentage of the total media player playout of any given day.
When creating a channel set the mixer mode to ‘Share of voice’:
🔎︎Click ‘Create’.
Select the newly create channel.
Click on a playlist preview to open the share of voice settings.
Change the percentage as required and enable shuffle if required:

Click ‘Save’ and then ‘Save and publish’ the channel.