Q995F + TCL C89B + ATV 4K – Surround Sound Issues (Stereo PCM Except for Atmos)

Platforms Apple TV
1

Hi everyone,

I recently installed my Samsung Q995F soundbar with my TCL C89B TV, and I’m running into some frustrating audio issues. I use an Apple TV 4K (latest gen) with Plex and Infuse for my content, but things aren’t working as expected.

Here’s what I’m seeing

Apple TV 4K (plugged into TV):

  • E-AC3 5.1 → Soundbar shows Stereo PCM :cross_mark:
  • TrueHD → Soundbar shows Stereo PCM :cross_mark:
  • DDP Atmos → Soundbar shows Dolby Atmos :white_check_mark:

I then tested directly from VLC on the TV (bypassing ATV) using a test file (“DD PLUS CHANNEL CHECK LOSSLESS”):

  • Soundbar shows Dolby Multi CH PCM :white_check_mark:

That’s what I think I should be getting from the ATV too… but nope.

Update – Installed Plex directly on the TCL TV:

  • TrueHD → Dolby Multi CH PCM :white_check_mark:
  • DTS-HD → DTS HD :white_check_mark:
  • AC3 → Dolby Multi CH PCM :white_check_mark:

So the TV itself seems to be doing things right!

Back to Apple TV 4K (plugged into TV):

  • Still Stereo PCM for everything except DDP Atmos, which works and shows Dolby Atmos

If I go into Apple TV settings > Audio Format > Change Format: YES:

  • Then I get Dolby Multi CH PCM for everything… :white_check_mark:
  • BUT I lose Atmos entirely :cross_mark: Thus, I have to change this parameter every time the audio format change (E-AC3 to/from atmos, nightmare to deal with)

:electric_plug: Apple TV 4K plugged directly into the Soundbar:

  • TrueHD, DTS, E-AC3 → All show as Multi CH PCM :white_check_mark:
  • BUT I lose Dolby Vision :cross_mark:

It feels like a constant trade-off: either I get Atmos and lose surround for everything else, or I get surround but no Atmos or Dolby Vision.

Anyone else run into this? Is there a proper combo of settings or connections that actually works?

Any help would be super appreciated!

2

It sounds like the TV may be modifying or limiting the audio coming from the Apple TV.

I’m not familiar with the settings for your TV model, but often times a TV will have options for ‘passthrough’ or ‘re-encode’ that would affect the audio that leaves the TV before it goes to the soundbar.

I found these 2 articles from TCL which may help with finding the correct settings.