[Messatsu]

Do any of your devices accept 5.1 PCM input ? Your Sony AVR won't (Toslink is PCM 2.0/DD/DTS only) and unless you have eARC, your LG soundbar will be PCM 2.0/DD and possibly DD+/DTS only too.  (I guess your TV might transcode PCM 5.1 to DD - some do something similar for AAC TV audio)

Do your LG soundbar and your Sony AVR support DTS and/or DD+?  If so then I'd enable DD/AC3 pass through, and also DTS and DD+/E-AC3 if supported - but disable True HD and DTS HD passthrough (as these can't be passed through by any of your connections by the look of it).  DD and True HD with a DD secondary stream (often hidden) will be output as DD, DTS will be output as DTS if DTS passthrough is enabled, DTS HD MA/HRA will be output as a DTS core stream IF DTS passthrough is enabled, otherwise it will be decoded to stereo.

If one or both of your devices don't support DD+/DTS then I'd enable 'Transcode to DD/AC3' as that will convert all non-DD 5.1/7.1 audio to DD 5.1 rather than decode to PCM 2.0 stereo.  (This will also allow you to listen to AAC, FLAC and PCM multichannel content in DD 5.1 rather than stereo PCM 2.0)

Thanks a lot, after checking 'Transcode to DD/AC3' it's working! I've bought a splitter to be able to read HD audio with my Sony setup, still waiting for the delivery! :-)

I thought your Sony amp was optical input only?  If you buy a splitter that has Toslink/SPDIF output - that won't give you HD Audio.  The only route to HD Audio is via HDMI input - or does your AVR support HDMI HD audio, but not 4K, so you have ordered an HD Audio HDMI splitter?

Hi,

I'll explain a little more, here's my setup :

Shield > HDMI > TV (Panasonic OLED FZ800)
TV > Optical output > SONY MDR-HW700DS 
TV > HDMI (ARC) > LG SK5 Soundbar (2.1)

I will now use (soon I will receive it) this audio extractor : https://a.aliexpress.com/_ACU3HV 

Shield > Extracteur (HDMI IN 1) > Extracteur Audio (HDMI OUT B Audio only) > SONY MDR-HW700DS : to be able to get HD audio
Shield > Extracteur (HDMI IN 1) > Extracteur Vidéo (HDMI OUT A Arc) > TV : for 4K HDR
TV > Optical output> SONY MDR-HW700DS : to be able to get the TV sound into my Sony headset
TV > HDMI ARC > Barre de son 2.0 : to be able to get Shield & TV audio

Maybe something's wrong, but I hope that it will work...