Wiz V2, Dolby Digital 5.1, and Sonos home theatre sound system

gvm · Post by **gvm** » Tue Jun 06, 2023 23:41

I have a V2 connected via HDMI to an LG tv. The optical output from the V2 goes via 3-way optical switch to a Sonos playbase controlled by a smartphone app.

When I select an HD Channel on the V2 EPG, I can confirm the V2 thinks it is producing 5.1 sound output because "Dolby Digital" icon is highlighted on the info bar, and if i press the audio button on the remote control AC3 is shown as the output audio track.

However, the sonos app shows that Stereo PCM 2.0 is being received, not Dolby Digital 5.1. My first question is how do I fix that? My Sonos successfully receives 5.1 from a bluray DVD player via the same optical switch.

Secondly, to see whether the TV connection via hdmi had anything to do with this problem, I disconnected the hdmi cable. I knew the V2 sound I was hearing via sonos was coming from the optical output because the sound came and went as I operated the optical switch. Thus after disconnecting the hdmi cable I expected to see the TV go blank and the sound continue uninterrupted. However it killed sound. Thus my second question: Should, or why does the audio optical output from the V2 depend on a video connection to a TV?

TIA ... Greg

MrQuade · Post by **MrQuade** » Wed Jun 07, 2023 21:53

gvm wrote: ↑
Tue Jun 06, 2023 23:41
When I select an HD Channel on the V2 EPG, I can confirm the V2 thinks it is producing 5.1 sound output because "Dolby Digital" icon is highlighted on the info bar, and if i press the audio button on the remote control AC3 is shown as the output audio track.

Those indications just mean that the T2 is receiving AC3, not that it is sending it.
To send Dolby to the audio receiver, you need to disable Dolby Downmixing from the Audio settings popup.

gvm · Post by **gvm** » Thu Jun 08, 2023 01:48

Thank you for your reply. I disabled Dolby Downmixing and the sonos system is now receiving 5.1. That's wonderful! I would like more explanation about this situation ... can you refer me to anywhere that I can read about this? TIA ... Greg

prl · Post by **prl** » Thu Jun 08, 2023 11:18

What do you want to know about it? Dolby Downmixing is a process where Dolby 5.1 sound is downmixed to stereo. Disabling it means that the original 5.1 audio is delivered.

MrQuade · Post by **MrQuade** » Thu Jun 08, 2023 23:26

gvm wrote: ↑
Thu Jun 08, 2023 01:48
... can you refer me to anywhere that I can read about this? TIA ... Greg

You might want to have a read of this thread.
This discusses some of the changes that were made to the audio features of the T series to improve the downmixing capabilities a while back.