Can't use dolby digital with xbox series s on tv or home cinema despite using digital audio...

Xbox series S does not have an optical output, the electronics industry has decided to eliminate them several years ago

If you mean a Xbox one S

Line would typically mean the analog RCA stereo

You need to use the audio return channel, ARC, consult your manual on how to enable that

I found a workaround for anyone that can use this setup.

I have my Xbox One S setup with HDMI out to the TV and an optical cable out to my Turtle Beach X41 Wireless Transmitter. I then used the optical out on that to go to my Sony Receiver and now Dolby Digital 5.1 is working.

I set optical audio to Bistream out, HDMI audio to off and Bitsream Format to Dolby Digital.

Sounds like a problem with the HDMI cable. Is it direct to the TV or through a home theater system and then the TV? If it is home theater you may need to run a digital audio / firewire cable for the audio to function into the receiver.

If you're direct to a TV check you system audio output settings from the Xbox dashboard far right system option. With an HDMI cord you'll ideally want to use Dolby output and let the device it is connect to decide if it will use Dolby or downgrade to a 2
channel R/L stereo mode.

Hopefully this helps you out a bit.

[quote user="JoshingJungle70"]

This did not help. Still no Audio on DVDs using HDMI cable....

[/quote]

Could you go into the console settings, and see what settings you have put for digital audio? The Xbox has settings for (I think) Digital Stereo, Dolby Digital and Windows Audio Surround. Set it to Stereo or Dolby Digital Surround only. I know of no device
that supports the Windows Media Audio thing.

To what audio equipment are you connecting your console? Your TV only, or are you using an AV reciever or audio amplifier to get sound?

Ok so you're getting audio from other sources on your TV? Try resetting your audio settings -

Go to Settings and select System.

Select Console Settings, and then select Audio.

Select Digital Output, and then select the digital output used by your audio system:

Digital Stereo

Dolby Digital 5.1

Dolby Digital with WMA Pro: This setting enables WMA Pro pass-through if your receiver supports the WMA Pro format.

If not, try a different HDMI port