This is a small pulseaudio script library, written to be used with keyboard shortcuts. However, it can also help in command line audio control.

IMPORTANT: set_all_sink.sh sources a file called sink_names.sh, this file should define a variable named $bluetooth_sink_name containing the identifying string for a specific device (i.e. the MAC address) like this:

#sink_names.sh
#!/bin/bash

bluetooth_sink_name="00_00_00_00_00_00"

To change the audio output device, use set_all_sink.sh
To change the master volume, use set_current_sink_volume.sh