Trying to get a Logitech z906 5.1 sound working with an optical cable through Sony 4k TV (1 Viewer)

[Paddy32]

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://i.imgur.com/iaun1GF.png

The TV has a built in Youtube button and when I go on Youtube and test the sound with a video like this :

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://i.imgur.com/xU9EZ6j.jpg (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://i.imgur.com/ovYmZKa.png ?) Is having 5.1 possible with my system ?

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

 

[Al.Anderson]

TV's are not the best choice for decoding signals; that said, the Sony seems decent and a receiver would be overkill for you (unless you decide to get "normal" speakers).
The only suggestion I have is, did you play with the 'Digital Audio Out' setting on the Sony (manual page 27).

 

[Paddy32]

TV's are not the best choice for decoding signals; that said, the Sony seems decent and a receiver would be overkill for you (unless you decide to get "normal" speakers).
The only suggestion I have is, did you play with the 'Digital Audio Out' setting on the Sony (manual page 27).

Hi Al.Anderson, yes I have tried to play with the Digital Audio Out setting, and all I have is "AUTO" or "OFF". I can't chose anything else.

 

[Paddy32]

Here is the diagram link, the imgur link I posted isn't working properly : https://imgur.com/iaun1GF

Also I went into the AV options and set the Audio Out to PCM : https://imgur.com/knZsjw1

 

[Paddy32]

I also found out in the AV options of the TV that I could set it to Auto 1 Auto 2 and PCM. See options here page 27 in the manual : https://www.sony.co.uk/electronics/support/res/manuals/4686/4686048EM.pdf I've tried all of them and none seem to work.

 

[Paddy32]

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.