Pulse audio runs as a server and a client . In order to configure pulse audio, you first need to install some additional programs:
sudo apt-get install "pulseaudio-*" paman padevchooser paprefs
Once installed, you need to launch the app on all your computers. It can be found as “Pulse Audio Preferences” in the Unity Dash or launched from the Terminal by running ‘paprefs‘.
On the computer connected to your speakers, use the “Network Server” tab, and check both “Enable network access to local sound devices” and “Allow other machines on the LAN to discover local sound devices“. I found I also had to enable “Don’t require authentication“, however, obviously this is not recommended for a public network.
On the computers you want to connect with check the “Make discoverable PulseAudio network devices available locally” option.
You should now be able see the shared output devices in the default Sound Preferences application.
If you don’t see the devices straight away, sometimes un-checking and re-checking “Make discoverable PulseAudio network devices available locally” will cause them to be discovered.
Also you can use VLC to do the job. Check this to learn how