[noggin]

First of all hello everyone. This is my first post here.

I have a question. I am an owner of Shield Pro 2019. I used Shield 2017 before but I upgraded it because of Dolby Vision and Dolby Atmos.

I try to find best audio settings. I connect my new Shield directly to AV receiver - Yamaha V483 via HDMI. This AV receiver doesn't have Dolby Atmos Decoder so I want to use build in decoder. In Kodi settings I turned off audio passtrough and in Shield settings I manually choosed all used audio codecs including Dolby Atmos and Dolby MAT (normally it should be set to AUTO but then Dolby Atmos and MAT are greyed out and not used). When I play movie with Dolby Atmos sound I hear all 5.1 channels are working (unfortunatelly I don't have Atmos speakers, but Atmos still should work. On receiver I see PCM but I think it shows it alwayswhen build in decoder is not working eg. when I play stereo movie form SAT TV it also shows PCM, when I play DD movie form SAT it shows DD.

Do You think it is set properly and Dolby Atmos is working with this settings? I think it is, but one thing bother me. When I use Netflix I can choose Dolby Atmos sound with this settings BUT I need to turn off Dolby MAT in Shield settings. Otherwise I had only standard 5.1 sound and it is a little strange for me but maybe it is because Netflix use Dolby Digital + Dolby Atmos?

Thanks in advance for Your help/opinion.

I think you are slightly confused.  If you don't have Dolby Atmos capable equipment - you will not need to decode the Dolby Atmos extensions.  

Dolby Atmos isn't a separate codec - it's an extension to existing codecs like DD+ and True HD.  You can have Dolby Digital + with Atmos Extensions or Dolby True HD with Atmos Extensions.  If you don't have a Dolby Atmos set-up then your system will just decode the Dolby Digital + or the Dolby True HD main audio stream, and will ignore the Atmos extensions that are used for positional and height stuff alongside the DD+ / True HD stream.

(MAT is a way of carrying Atmos over HDMI and is separate to the codecs used - it's more of an output standard)

With Kodi on the Shield and an AVR you have a choice of either outputting bitstreamed pass through audio (DD, DTS, DD+, Dolby True HD, DTS HD MA/HRA) or letting Kodi decode this to PCM 2.0/5.1/7.1 and outputting in PCM.  Personally I'd probably go with the former - in fact that is what I do.