I have a strange issue with my set up where certain discs will not play audio during films through my Sound system (they work fine for others and in the menus play fine on all). My set up is as follows: Sony KD-55XD9305 TV Panasonic DMP-UB700 Ultra-HD 4K Blu-ray Player Sony RT3 Soundbar and Speakers I also have a Panasonic DMR-BWT700EB Blu-ray and HDD recorder plugged in. The 4K Player is connected via HDMI from the Audio+Video Out to HDMI2 on the TV. The Soundbar is connected from HDMI1 (ARC) on the TV to the HDMI input. The HDD recorder is connected to HDMI3 on the TV. I have tried numerous HDMI cables and the latest ones are all HDMI 2.0b/HDCP 2.2 with support for 4K @ 60Hz 4096 x 2160p HDR UHD 4:4:4 18Gbps. Most of my 4K Blu-rays work fine including The Martian, Sicario, Passengers, Saving Private Ryan* etc. However there are some that just won't play audio through the Soundbar: Dunkirk, The Accountant, Unforgiven, Despicable Me 3? I've found from what I can tell that all standard Blu-ray discs also fail to play sound through the soundbar. Blu-ray 3D discs seem hit and miss - for example Puss In Boots 3D works fine, while The Lion King and Jurassic Park 3D don't. DVDs work fine (as you'd expect). I can always drop back to the TV sound (although it defeats the point of having a sound system), and when I play Blu-rays through my other player (HDD recorder) the sound works (although there is often an annoying lag). * Interestingly I had problems getting Saving Private Ryan 4K to work - it came up with a message saying that I needed 4k equipment to play it. This prompted me to replace the cables (again) and after much fiddling (I discovered the Enhanced Mode for HDMI on the TV which was disabled by default - and enabled it on all ports) it eventually just worked. Next time I put the disc in though the same message came up. After more fiddling, during which the 4K player did a firmware update it just worked again. I suspect I'll continue to have issues with that disc? Any ideas? I think I've tried just about every setting I can find on the player and the TV and I'm fed up of buying and trying new cables (not to mention the cost) which seems to be all the advice I've seen seems to suggest.