• 4K if your TV is 4K. Otherwise 1080p. | Output Resolution: 1080p or 4K (experiment between those two, only)
• On but as Don said, this only matters if you let the player do the audio decoding. | Secondary Audio: Off (the only way to get Dolby Atmos & DTS:X)
• LPCM so that the player can do secondary audio mixing. | HDMI Audio: Bitstream (the best; your Yamaha do all the audio decoding)
• On. | HDMI Decoding: On (Yes, Amir is correct)
• You should set this to OFF if you are using an AVR. This is only useful if you are using the analog outputs of the OPPO and are driving subs.
In that case 80 Hz is the right answer almost all the time. | Crossover: 80Hz (leave everything @ default; it don't matter - it's only for the multich. analog connections)
• Off. | Dynamic Range Control: Off (Amir is correct again)
• If you have more channels than what is on disc, you can play with these settings. Otherwise Off. | DTS Neo:6 Mode: Off
• Fixed. | Output Volume: Variable :b
The processing in AVRs can be quite poor. So I would let the Oppo do it. ON 4K setting, if the Yamaha cannot pass it and you have a 4K TV, route the one output to the TV direct.
* In red ? is my own feedback. :b