Bravia KDL-42W705B - AAC transcode or pass through?

[washboardmac]

Hi

I've had the above TV for 2 or 3 years now and new AV amp for 6 months (Marantz 1506.)  I've never got the ARC working properly - HDMI-CEC was fine but not TV audio) and so over Xmas decided to have a closer look.  I eventually traced it to an HDMI cable that was maked as 'hi-speed' but clearly wasn't!  Swapped this over and bingo, sound!

However when I selected a Freeview HD channel - in fact any of them - again no sound.  The app on my tablet that can control the amp was showing that the input format was 'unknown'.  I had been through all the menus on the TV and the amp when troubleshooting the ARC problem and so went through them again.

Now here's the odd bit.  The only way I got sound working on HD channels on the amp was to set the Optical Out to PCM (it had been left on Auto.)  So I got sound, but only stereo.  OK I thought maybe there is no surround being broadcast at that moment but tonight I checked using the USB HD tuner in my PC and a film on Channel 4 HD was broadcast in 5.1 AAC, as confirmed by my software (DVB Viewer.)

So, two questions:

1.  Why should an option clearly marked as being for the Optical Out affect HDMI ARC?

     I find this very odd and only tried it as a last resort.

2.  What does this TV do with the AAC sound being received on the HD channels?

     I can't find a definitive answer as to whether the TV transcodes AAC to DD or multi-channel PCM, if at all.

All help and advice greatly appreciated.

Cheers

Andy

[Anonymous]

Hi there,

I will look into this and get back to you.

Best wishes,

M

[Drewde]

Hi,

Welcome to the Community.

1. To my knowledge it affects the HDMI ARC signals as well.  I'm looking further into this and will update you when i have more.

2. The TV itself can handle most audio formats but some can’t be sent via HDMI since HDMI does not support these formats. When using optical out format will be sent as it is but AVR needs to support these formats as well. E.g. if the AVR can't handle Dolby Digital+ (used by many services meanwhile) then you won't hear any sound.

Thanks,

Drew