The mystery of the surround sound

by aruku64

This has been driving me crazy for months now... Hopefully somebody can help me out.

I have a Shield TV 2017 that is able to passthrough pretty much every surround format out there. It is connected to a Vizio E55-C2 via HDMI, and it is set to Bitstream, as I understand has to be for HDMI-ARC to work; that way it connects to a Vizio SB4051-C0 sound bar, and it is also hooked up with an optical cable. This sound bar understands DD and DTS.

As far as I know, Netflix provides DD+ surround, but not basic DD; but for some reason, I get sound out of the rear speakers too, and without being an audiophile, I'm pretty sure it is not just the stereo being duplicated or anything like that. The stereo upmix to 5.1 option on Shield is disabled.

How is this happening?

latinriky78

Dolby Digital Plus to Dolby Digital conversion is reportedly working on the Nvidia Shield 2019 only, unless they already implemented the feature to the other shields in any update but I haven't heard or seen any news about it.

However, if that's not the case, then you have your Shield connected to a 2017+ Smart TV which started to support Dolby Digital Plus by HDMI, and since eARC is just arriving to recent models, what you are getting instead is a conversion done first by the TV to be output to the HDMI-ARC/optical ports to whatever home theater or soundbar you have connected.

daschu117

Netflix will provide the best that your TV claims to support, which would be DD+, despite ARC and optical not being able to carry it. Your TV will happily understand the DD+ codec even though it's not capable of doing 5.1 on its built-in speakers or to the soundbar over the connections available. It might be and to internally transcode DD+ to DD before sending it to the soundbar.

On the Shield 2019, you can manually disable the advanced codecs so that apps only pick up what you want. This let's me disable everything except basic DD so that Netflix and Plex make sure to either present or transcode to DD. My Samsung TV doesn't support detecting and switching between DTS and DD, so I would normally have to swap between them depending on what I was watching. This caused my to stop using the Shield 2017. Then some time passed where I was content to use the TV apps. Finally, they released the 2019, which included the manual codec selection which fixed this issue since Plex can be told to transcode DTS to DD, and I can disable DD+ globally to fix Netflix.