If you own a 220, 320, 420, 555, 580 model ZVOX and you are connected via Optical to the TV and have NO audio, you must make sure you are set to the right input with the remote and change the audio format of the TV through the TV's audio menu using the original TV remote. You must go into the audio settings and search for the option to change the audio format and set it to PCM and you will hear the audio appear.
If you have any questions please email us at info@zvoxaudio.com