Originally Posted by david0406
Currently I have a 5.2.2 Atmos configured setup. I have generally only ever really made true use of the Atmos configuration when listening to Blurays with an Atmos codec. I have the bluray input on my AVR set to "straight decode." With my streaming box since there is not much content that is actually in Atmos I have always had that listening mode of that particular input set to "Dolby Surround" since most of the content I listen to is in the DD+ codec, just to make use of my elevation speakers. Now that Disney+ is actually streaming some of it's content in the Atmos codec does it degrade the Atmos audio signal to have that signal listened to in the "Dolby surround" listening mode or should it be set to "straight decode" like the bluray input is set to? I think the "Dolby surround" mode is just a different name on Onkyo's to replace the "Dolby PLIIz" listening mode on older generation Onkyo's. I believe the AVR in PLIIz mode only upmixes sounds to the elevation channels whereas Atmos codec has sounds actually has sounds specifically mixed for the Atmos channels. I think that is how that works and why I wonder if listening to an actual streamed Atmos mix might get degraded (in theory) by the AVR if listened to in a "Dolby surround" listening mode instead of "straight decode." Is my thinking correct?
No you're thinking isn't correct
First off, Dolby provides the libraries to the vendors so any receiver that decodes "Dolby" or has "Dolby Surround" has to basically handle it the same way as it's passed to Dolby's decoder provided and written by Dolby. Dolby Surround is probably the mode you always want on all your video sources. Dolby surround will upscale all sources to Atmos. If the source is already Atmos, then it plays it without modification. The receiver should be smart enough also to pass DTS-X unfettered as well. But Dolby Surround would upmix DTS to Dolby Atmos. The only time you probably don't want your setting at Dolby Surround is when playing 2 channel music.
Also, "Dolby PLIIz" stuff all got replaced, again by Dolby (it's their library, their branding names for each mode), and it's just "Dolby Surround" now.
In my opinion, Dolby's upscaler is incredible. It does a fantastic job on 2 channel audio expanding it very well so that voices are only in center and ambient sounds are where you expect them to be. Even rain sounds come from above. (By the way, 5.x.4 is the sweet spot. If you can get 2 more speakers for a 5.1.4 setup, you'll have a decent benefit).
Video: JVC RS4500 135" screen in pure black room no light, htpc nvidia 1080ti.
Audio: Anthem mrx720 running 7.1.4, McIntosh MC-303, MC-152, B&W 802d3 LR, B&W HTM1D3 center, B&W 805d3 surround, B&W 702S2 rear, B&W 706s2 x 4 shelf mounted for atmos, 2 sub arrays both infinite baffle: 4x15 fi audio running on behringer ep4000 + 4x12 fi audio running on 2nd ep4000.