ansible/roles/pi-alsasetup/templates/asound.conf

pcm.soundcard {
   type hw
   card {{alsa_card_name}}
}

ctl.dmixer {
   type hw
   card {{alsa_card_name}}
}

pcm.dmixer {
   type dmix
   ipc_key 1024
   slave {
      pcm "soundcard"
      channels 2
   }
}

pcm.dmixer_plug {
    type plug
    slave {
       pcm "dmixer"
    }
}

pcm.softvol_shairport {
    type softvol
    slave {
       pcm   "dmixer_plug"
    }
    control {
       name "ShairPort-Sync Volume"
       card 0
    }
}

pcm.softvol_squeezelite {
     type softvol
     slave {
        pcm "dmixer_plug"
     }
     control {
        name "SqueezeLite Volume"
        card 0
     }
}

pcm.softvol_effects {
     type softvol
     slave {
        pcm "dmixer_plug"
     }
     control {
        name "Effect Volume"
        card 0
     }
}