Dolby Digital greyed out

[Bobelberg]

Hello everybody.

Since my grandpa gave me his old Samsung TV (Model name is: UE32F5570SS) and I still had a Sony 5.1 Surround System laying around, I wanted to connect them for the best Movie experience. Since this TV Model, due to its age, doesn't support modern Streaming Plattforms like Netflix or Disney plus, I used my FireTV Stick 4K, connected to my TV's HDMI Input, to be able to watch what I want. My Sony Surround System is connected to the TV via optical cable and the sound works, but apparently is not true 5.1 Surround. When looking into the TV's Sound Settings, only the Options "PCM" and "Neo DTS 2:5" were available, while Dolby Digital was greyed out. Can somebody help me with my problem, to achieve real 5.1 Channel Sound?

Thank you Already and greetings from Germany

[Ginga_p]

Unfortunately optical cable can not handle a dolby 5.1 signal.

[lminvti]

Hi there, did you tried connecting to ARC/eARC channels at the back of your tv?

[Bobelberg]

Why can't it though? Technically, it can. As for my home theatre setup, consisting of a Teufel Concept E 5.1 System, the designated Decoderstation and a 4k Projector, an Optical Cable is used to achieve actual 5.1 Dolby Digital surround. Why can't it though when it comes to Samsung TV's?

[Bobelberg]

There don't seem to be any ARC ports for my TV model. 

[lminvti]

That might be the issue usually it's connected through HDMi

[lminvti]

Because HDMI eARC/ARC output provides best quality

[Ginga_p]

Optical S/PDIF (toslink) is routinely used to transport standard Dolby/DTS 5.1 digital audio signals between players and receivers. And that's because Dolby/DTS 5.1 digital audio is not typically passed as PCM, it's passed as a lossy-encoded bitstream, which is converted in the AVR. If you convert to 5.1 PCM in the source device, and try to pass it to the AVR, then you can't use optical or coaxial S/PDIF, you have to use analog or HDMI.