Trying to get a Logitech z906 5.1 sound working with an optical cable through Sony 4k TV

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Hello,

Before I start I want to say that I know that the z906 kit has a very poor sound quality and is trash for a home cinema. I have had this kit for 6 years now, used it to get 5.1 sound for my PC and would like to recycle it now into a home cinema before buying a proper sound kit. And also that I'm not an expert in home theaters.

I bought a 4k Sony TV (54.6" Sony KD-55XE7096) and set up the Logitech z906 and also mounted the satellites to the walls. I'm using an optical cable to connect the Sony TV directly to the Logitech z906 backpanel. I would like to get 5.1 sound.

Here is a diagram : https://imgur.com/iaun1GF

The TV has a built in Youtube button and when I go on Youtube and test the sound with a video like this : https://www.youtube.com/watch?v=PqVCPE8_ntE the speakers don't react like they should :
- when FL and FR play, all speakers are used
- when center plays, only center speaker is used
- when RL and RR play, all speakers are used
- when LFE subwoofer plays, nothing happens

When I play a Netflix 5.1 program and select in Audio the 5.1 language, the RL and RR speakers don't seem to be working as 5.1 speakers.

I've been trying to find out why it's not working, and I'm pretty sure for some reason that I'm missing something. I checked in my TV options and have the Dolby Digital set to Auto : https://imgur.com/xU9EZ6j(I can only chose "AUTO" and "OFF")

Do I need to buy a reciever ? Does the sound need to come out via ARC HDMI from the TV ? Do I need something like a "Optical to 6 channel" unit ? (https://imgur.com/ovYmZKa ?) Is having 5.1 possible with my system ?

Thank you for all your answers, I am very grateful.
 
Last edited:

TJM

TJM

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What happens if you set Dolby Digital to off? The base unit may not be able to process the signal.
 
Soldato
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Chances are the TV won't route the 5.1 correctly. I have some thing similar where the PS4 goes to the TV (ks7000) via HDMI, but the optical out of the TV doesn't route the 5.1 correctly into my Logitech unit. Optical from the PS4 to the Logitech unit works fine so I just switch inputs.
 
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By the way I played Season 1 Episode 1 of Netflix Test Patterns, and the 5.1 works !!! Each speaker works as intended ! It means that only the Youtube App can't push out 5.1, only Stereo.
 
Man of Honour
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Give this a check:


Sony TV Menus > Advanced Settings > Dolby Digital Plus Out

Dolby Digital Plus Out: Select [Auto] to pass through Dolby Digital Plus stream to ARC when Dolby Digital Plus is available through connected Audio System. During Dolby Digital Plus stream is output, Digital Audio Out (optical) is muted.

Select [Off] to convert Dolby Digital Plus stream to Dolby Digital for both ARC (Audio system) and Digital Audio Out (optical).
 
Soldato
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By the way I played Season 1 Episode 1 of Netflix Test Patterns, and the 5.1 works !!! Each speaker works as intended ! It means that only the Youtube App can't push out 5.1, only Stereo.

Youtube is stereo only, so that's why you won't get 5.1 when using that whatever you do. Z906 should have Dolby Pro Logic II, I would have thought, which can upmix stereo to 5.1 for sources like Youtube. Anything on Youtube that is supposed to be 5.1 gets squashed down to stereo.
 
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Give this a check:


Sony TV Menus > Advanced Settings > Dolby Digital Plus Out

Dolby Digital Plus Out: Select [Auto] to pass through Dolby Digital Plus stream to ARC when Dolby Digital Plus is available through connected Audio System. During Dolby Digital Plus stream is output, Digital Audio Out (optical) is muted.

Select [Off] to convert Dolby Digital Plus stream to Dolby Digital for both ARC (Audio system) and Digital Audio Out (optical).


So I should select OFF ?
 
Soldato
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Some TV's only output 2 channel sound out of there optical output

Have you checked if your TV does output 5.1 through it optical output ?

You should be able to find what your TV outputs in the online manual,
This below is from the manual for my Sony TV
gI40NGO.png
 
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