Vudu: no surround at all with 7.1 output

My question above was simply: 'does the XBOX One S have simulation capabilities for simulating ATMOS sound from a 5.1 or 7.1 surround input'? My system is functioning fine. I only ask because I tried setting the XBOX to ATMOS out with a 5.1 Dolby input
from VUDU and my receiver displayed that I was receiving an ATMOS signal from the XBOX. I am using all highspeed 4k capable HDMI cables on all inputs and outputs.

Hey there,

The Xbox 360 console doesn't support 7.1 surround, only 5.1 Dolby Digital and DTS. Due to this, it is normal that backward compatible games are outputting 5.1 surround. On your Xbox 360 setup, it sounds you have it set up with Pro Logic IIx to simulate 7.1
surround sound, but the Xbox 360 console doesn't support true 7.1 surround sound.

Hope this helps clear it up.

No 7.1 surround here (XO7s). Stereo only, until MS decides to output other than stereo through the adapter. Basically, the same as XO4s now..

I'm having the same issue. Only seeing a 2 channel, stereo output. I've tried every surround sound option (5.1, 7.1, bit-stream, surround sound on/off, etc...) and I've changed around the HDMI settings with no luck. The output is only stereo for OTA live
TV. When watching movies or other content surround sound works fine.

Many games will output music and some sound effects only from the left and right channels, even though the output stream remains 5.1. The center and surrounds will be quiet. The same goes for music playback on the Xbox 360, it keeps the left and right inputs
in the corresponding outputs but leaves the center and surrounds silent.

TV commercials and promos may be produced in anything from 2.0 to 5.1, so if the sound comes only from the front left and right, it's probably just the way it was mixed. Broadcasters are wary of applying expansion on 2.0 sound to 5.1 in advance since it may
compromise downmixing back to 2.0 in the TV or set-top box. Switching the channel configuration on the fly depending on content in turn may cause a short moment of silence, so it's usually only done at the start and end of programs.

So the channel indicators on the receiver only indicates that those channels are present in the stream.

When you enable Dolby Pro Logic II to 2.0 input, if it's surround encoded those sounds will be dominant in the surrounds. But naturally occuring differences between left and right will also come out partially from the surrounds, whether the content is surround
encoded or not. This is called "magic surround". In the Movie and Game modes of Pro Logic II the magic surround is partially masked by delaying the surround outputs relative to the front outputs (by about 10 milliseconds), but it's still fairly audible. The
main purpose of the delay is to mask dialog sibilants that have leaked into the surrounds in processing.

There are three flavors of Pro Logic II. The basic version supports expanding 2.0 input into 5.1. Pro Logic IIx adds back surround support for 7.1 output. Pro Logic IIz adds height surround support for up to 9.1 output. The method for achieving the expansion
into the additional channels varies depending on the input (2.0, 5.1, 7.1). With 5.1 and 7.1 input the processing is done only on the surrounds.

Preferrably the receiver should indicate which one is used based on the speaker outputs you have enabled. If you have back surrounds but no height speakers, it should indicate Pro Logic IIx rather than Pro Logic IIz. But I'm not sure if all manufacturers do
that.