No 5.1 center channel

@JimKnopf
When the TV speakers are set to On , DTS signals
cannot be passed through digital audio outputs.

So, what happens if you set the TV’s speakers to OFF ?

Good question. I didn’t actually touch that one, I always left them set to “auto”. They are turned off automatically when the soundbar is connected, so it didn’t occur to me to explicitly change the setting. But I could see a path in the TV’s logic where even though the internal speakers aren’t used when the soundbar is connected, this other behavior remains. Will definitely try it tonight!

I have a similar setup, but I use Toslink from Vizio to older AVR . Vero4K - HDMI - Vizio - Toslink - AVR

Configured as Follows
Vizio Audio Setup

  • Speakers Off, Surround Sound Off, Volume leveling Off, Volume display Off, Digital Audio Out Auto

Kodi Audio Setup
Audio Output Device - AML-M8AUDIO, HDMI
Number of channels - 5.1
Allow Passthrough - ON
All Formats ON, except for DTS-HD which is OFF.

My AVR does not support DTS-HD, and I do not see it listed in your Soundbar specs either. If enabled I lost the center channel.

@Wheelz I would try

Vizio Audio Setup

  • Digital Audio Out Bitstream (if possible)

Kodi Audio Setup
Audio Output Device - AML-M8AUDIO, HDMI
Number of channels - 2.0
Allow Passthrough - ON
AC-3 passthrough ON
AC-3 transcoding ON
DTS passthrough ON

TrueHD, DTS-HD passthrough OFF

I guess I should have mentioned that my setup is working perfectly with this configuration. No need to change anything. Mine is an older AVR, no HDMI, no 7.1, but it works fine for 7.1 tracks and DTS-HD.

@Wheelz
my setup is working perfectly

This is the same TV as mine (P75-F1)? Definitely going to give it another shot with Vero → HDMI → TV → Soundbar then. I was away over the weekend and still haven’t tried setting the speaker to “off” so maybe that was it.

Welp, I hooked Vero back up directly to the TV. TV speaker set to “off,” audio “bitstream.” Same results as before. No center channel. Soundbar only ever receiving 2.0.

Vero4K → HDMI → Vizio → HDMI-ARC → Soundbar = 2.0 only ever

Even more puzzling:

Vero4k → Toslink → Soundbar = 2.0 only ever

Audio: AML-M8AUDIO, HDMI
Number of Channels: 5.1
Results are the same with allow passthru on or off, any or all feature support disabled or enabled.

So the only way I can get 5.1 from the Vero 4K is to hook it up to the soundbar directly via HDMI. It is baffling to me that this works but optical will not. (The 2nd image shows the audio format; when it’s working that is LPCM 5.1)

@jamie Have you tried the Kodi audio settings I suggested?

Start with even DTS passthrough disabled on first try.

This is the problem. You need to set channels to 2.0 when using TOSlink as @JimKnopf has said.

@JimKnopf
Start with even DTS passthrough disabled on first try.

I’ve tried that. I’ve tried every combination of enabled/disabled/features in the the passthru settings. None of it makes a difference when Kodi is hooked up to the TV rather than directly to the soundbar.

@grahamh
You need to set channels to 2.0 when using TOSlink as @JimKnopf has said.

Oh sorry - I was following what @Wheelz said was a working config.

So you’re saying in order to get 5.1 audio I need to set it to 2.0? Um… I’ll try it…

apart from making no sense, why would this work? Unless it was set to passthrough (in which case, my understanding is from what Kodi says on the screen, that this setting doesn’t matter) why on earth would setting in to 2.0 result in my getting 5.1 audio? Isn’t this setting exactly what tells Kodi how to transform the audio?

I know it’s counter-intuitive to some. S/PDIF can carry only two channels - either stereo or two compressed channels in DD or DTS format. When you enable AC-3 (ie DD) transcoding, kodi compresses 6 channels into a DD format, but you have to set channels to 2.0 for it to do that.The link to the wiki @Chillbo posted right at the top of this thread tells you.

When you are using passthrough, the channel selection is typically not relevant (as in selecting 5.1 when you expect to receive those channels) since passthrough is intended to pass untouched data to the decoding device. I know it does seem a bit counter intuitive.

@grahamh
I know it’s counter-intuitive to some. S/PDIF can carry only two channels - either stereo or two compressed channels in DD or DTS format. When you enable AC-3 (ie DD) transcoding, kodi compresses 6 channels into a DD format, but you have to set channels to 2.0 for it to do that.The link to the wiki @Chillbo posted right at the top of this thread tells you.

I can understand that, generally, but what doesn’t make sense to me is how this works in practice as far as these settings go?

When passthrough is not enabled, because a particular audio format isn’t supported by the target, how will Kodi know what to transform it to? e.g. suppose my soundbar only supports 5.1, and I have a 7.1 stream, how will Kodi know what configuration to convert that to, if I’ve selected 2.0?

If you are using passthrough, Kodi does nothing but send raw audio data. It’s up to your connected devices to determine how it should be handled. In such an instance though, selecting 5.1 in Kodi actually does affect the data in a way that confuses your devices.

It’s actually quite simple…

The amount of channels you select (2.0 for TOSLINK) are only affecting PCM playback. TOSLINK only supports 2.0 PCM channels, thus this setting.
If you have a 7.1 stream, Kodi will take those channels and mix them down to 5.1 and then transcode it to a 5.1 DD stream on the fly. This will happen with all PCM streams that have more than 2.0 channels and TrueHD/Dolby Digital Plus streams. For DTS-HD streams, the core DTS track will be sent to the AVR via TOSLINK.

I’d really urge you to read the wiki article I linked to above… It does explain all of this in great detail - also the AC3 transcoding, which settings to choose in which environment and also the supported audio formats for each connection type. :wink:

It will say: this is multichannel so I will encode it to AC-3. AC-3 can only do 5.1 channels so that’s what I will send