When you connect to a projector your audio should automatically switch from your laptop speakers to that projector.  If it doesn't, change it manually from System Preferences:


Directions

  1. Open System Preferences and choose Sound:
  2. Select the Output tab at the top:
  3. Change from MacBook Pro/Air Speakers to the name of the projector, EPSON PJ in this case. Typically you will only see two options above all the AirPlay options. The sound should start coming out of the projector's speakers now:



Troubleshooting

Sometimes the audio will not change and will always keep coming from your speakers.  In that case, reboot your computer and try again.  If the issue persists please open a help ticket.