Dolby Atmos sound track issues with MKV

[Horsham101]

I am new to this community and need some help if possible.

I have a Bravia XR 65A9k TV and Sonos Arc and 2 x Era 300 for dolby atmos connected via eArc.

When looking at the Sonos app to establish the sound track for movies I am playing either via my Panasonic 4k player or streaming via Netflix or Prime, if the films have Dolby Atmos I get that sound track displayed in the Sonos App and also pressing the 'Audio' button on the TV remote displays TrueHD Atmos. However when I play films from my NAS connected via Ethernet LAN using VLC app installed on the TV, which supports Dolby Atmos, all I see is Dolby Digital Plus 2.0. The films have both TrueHD Atmos and DD5.1 sound tracks available. If I switch to the DD5.1 sound track, that is then displayed in my Sonos App.

If I use the default media player on the TV it only supports DD5.1 sound tracks and there is no sound if selecting TrueHD

I have spoked to Sonos support who have run diagnostics and assure me that the Sonos speakers are fine to receive TrueHD Atmos.

They believe the problem is between VLC and the TV but given I can play Atmos via other apps such as Netflix and Prime streaming services there should not be any difference streaming via VLC/NAS all of which go through the tv.

I have passthrough set and audio output to dolby audio.

Finding it very frustrating that I cannot play films stored on my NAS with TrueHD Atmos and hoping someone may be able to offer advice?

Many thanks

[daveyh64]

With VLC player have you checked that its own audio settings are set to Passthrough.

And while you are at it double- check your TVs Audio output is set to Passthrough - Auto.

[Horsham101]

Hi - yes checked passthrough is on both. After more investigation I have noticed that VLC for Windows has a 'preferences' tab and I was having trouble with Atmos on my laptop until I set passthrough to HDMI/SPDIF and then Atmos played on my laptop. The Android version doesn't have audio preferences only passthrough which maybe generic as the windows version has 3 passthrough options, Disabled, Enabled (AC3/DTS), Enabled HDMI/SPDIF. As the latter worked for my laptop I was wondering whether the passthrough for the Android version defaults to Enabled (AC3/DTS) without any other options and Atmos not getting through. As a result I have contacted VideoLAN to see if they have any solutions to my Atmos issue using VLC for Android.

Many thanks for your reply. 

[MaggieGreene]

Hi @Horsham101, I don't think stored films can be played with Dolby Atmos feature. However, you can try the NAS with a different device other than the TV to make sure if the issue remains. If it doesn't, try to disconnect the NAS and connect it back in after 2 minutes, unplug the TV from the mains and plug it back after a minute, and ensure that it has the latest software update: https://www.sony.co.uk/electronics/support/oled-tvs-android-a95k-series/xr-65a95k/software/00349283 

[Horsham101]

Hi @MaggieGreen

Thanks for your reply.

Tried all that and further checks.

Have VLC Player on my laptop and played a film from the NAS and shown as Dolby Atmos. Connected the laptop via hdmi to TV and Sonos shows Dolby Atmos.

I believe the problem is with any non-pre-installed apps (VLC, Kodi etc) loaded to the TV even though they support Dolby Atmos, the sound is not passed through by the TV. I have checked all pass through settings on TV and apps and all correct. All they play is Dolby 2.0 which was confirmed by Sonos support monitoring my system remotely.

The pre-installed apps such as Netflix and Prime play Atmos without any issues and displayed as such on Sonos App. Sony's pre-installed Media player only handles Dolby Digital 5.1 (shown on Sonos app) and not Atmos.

So in all I believe Sony need a system tweak to enable non-pre-installed apps to pass-through Dolby Atmos. I don't want to keep playing NAS stored files with VLC via my laptop to my TV, its clumsy.

I need to contact Sony direct but cannot find any support numbers/emails - anyone any suggestions?

Thank you