In order to allow your system to be detected as an A2DP sink (e.g. to play music from your phone via your computer speakers), add `Enable=Source,Sink,Media,Socket` under `[General]` in `/etc/bluetooth/audio.conf`.

After doing this, restart the bluetooth daemon

    systemctl restart bluetooth

Connect you headphone device

    bluetoothctl
    connect <MAC>

Check your card and set profile

    pacmd list-cards
    pacmd set-card-profile <index> <profile>