LG CX 'Optical + Internal TV Speaker' setting isn't Dolby Digital?

[sjw]

I'm just connecting up an LG 55CX. For general viewing I just use the internal TV speakers and think they're fine - and 'wife friendly'.
I also have a 'simple' AV setup (an old Acoustic Energy Aego P5) that gets its input from Optical - no HDMI ports at all. Again, it does me.
Previously I had a Samsung and it output sound via TV speakers and also via optical simultaneously. I would only use the external speakers when watching from external sources - a Firestick or a PC - both connected via HDMI. I just turned the TV speakers down and got full 5.1 Dolby Digital or DTS through the AV Speakers.
So, I'm now setting up the LG and noticed a separate Sound option for 'Optical + Internal TV Speaker'. Sure enough, the sound is output to both sets of speakers.
However, I can't seem to get surround sound with this setup? Am I doing something wrong? My amp just displays PCM. The HDMI Input Audio Format is set to Bitstream.
If I switch the Sound output just to Optical, the amp displays Dolby Digital and I get proper 5.1 DD. Is there anything I'm missing here - or do I need to keep switching between internal speakers and optical? I do have a Harmony Elite - I assume there are no direct commands available either.

 

[fearsomebows]

Hi i set optical out in advanced options to mpeg and all sorted now every input works with Dolby digital from sky xbox and amazon prime Netflix etc

 

[sjw]

Hi, not sure where you mean for 'Optical out'.
I needed up creating Sequence on the Elite that navigates to select either Internal TV Speaker or Optical. Digital Sound Out is set to Auto.
The only mpeg setting I see relates to DTV Audio.

 

[dorfv]

Hi sjw, I have the same problem, did you find a solution for having a ( wife friendly ) permanent internal speaker on LG65 and at the same time having dolby optical output available for the main amp. if required , without having to change settings ?
I have tried using the 'internal speaker +optical ' setting but cannot get dolby from the optical...it is stuck on 'dual channel', optical on its own works fine, surely there must be a way ?

 

[sjw]

Hi, no, unfortunately I never got a good solution. There doesn't seem to be a discrete code to enable the speaker option you want (like you can do for HDMI source). I still find it strange that with both speaker options selected that the external output isn't DD - unlike the 5+ year old tv it replaced.
What I did is I created a macro on my Harmony remote that basically recreates the manual button presses to go into Settings, Down, Right, down etc... It usually works but occasionally, if the TV is a bit slow responding the programmed options end up switching the picture to Energy Saving mode or something!
The other thing that winds me up is the button to switch to TV Source isn't really that at all - if you are already on TV it switches to Radio mode and I can't see any way of disabling the Radio that I have no interest in. This means, on the Harmony, when it switches the TV on and it's told to be on the Live TV option it switches to Radio Again, a workaround is to make it go to a specific TV Channel (eg 101) but it's not really ideal.