What is "Expert Mode" audio output on the Contour 2?

My take...

Auto Detect:  HDMI output based on the capabilities of your connected audio system
Expert Mode:  The best available Dolby sound will be passed through to your audio system.  Not compatible with...blah, blah, blah.

There are key words in each description.  Auto Detect states, "...based on the capabilities..." and Expert Mode states, "...passed through..."

With Auto Detect, Contour will negotiate with your audio device for the best format from within the range of 2-channel Stereo to Dolby Digital 5.1.  This range is basically the standards for cable TV.

With Expert Mode, Contour will disable negotiation and just pass through the audio data to your audio device.  Your audio device will then decode and separate the audio channels.  I think the "minimal" difference you hear is between Contour and Sony processing the audio.

To clarify your question, are you asking if Expert Mode could automatically switch to a LESSER audio format?  I wouldn't think so.

First, we're talking about cable TV.  The most advanced audio from regular TV programs would be DD5.1.  Sony can handle DD5.1, so I wouldn't think your sound bar would dumb down from DD5.1.

Second, because your sound bar can process Atmos, it has a more advanced audio chipset than Contour; in addition, because your sound bar is designed solely for audio, it has a better audio chipset than Contour.  Meaning, there would be no lesser audio format for your sound bar.

I would leave it on Expert Mode; however, if you experience issues with audio-video sync, I'd switch to Auto Detect for Contour to set the timing.