Instructions
Start the PlayStation 3 and navigate to the video tab on the main menu. Scroll down the list to access the Netflix application.
Start Netflix normally by pressing the "X" button on the controller. Netflix may take a few minutes to load, depending on your network speed.
Navigate to the desired movie or television show you wish to view that doesn't play any sound. Press the "X" button to select the title. It may take up 30 seconds to access this title, depending on your Internet connection speed and network traffic.
Select "Audio and Subtitles" from the title sub-menu. It will be the last item on the list. If "Audio and Subtitles" does not appear on the sub-menu, then the title you have selected has no additional audio options, such as subtitles or surround sound support. The audio for those titles will default to stereo, which should play on any properly configured audio setup.
Select "English (Stereo)" under the "Audio" heading. Replace this if there is another language track available; select the setting you desire, as long as it contains the "(stereo)" postfix.
Play the title. The audio should now be directed to stereo output, rather than attempting to play using a non-existent 5.1 surround sound setup.