No Audio while playing Dolby True HD content through Receiver/HDTV- Help Required

[Ashim]

Dear Big Picture Big Sound Team,

I have recently set up a home theatere component system and here comes the first problem !

Much appreciate if you are able to help me with this.

Problem :
There is no audio output while playing blu ray (Dolby TrueHD content). Video works well. Once the disk is played the receiver lights up and Digital logo comes alive displaying Dolby TrueHD on the receiver display. There after it is like watching a silent movie on the TV without any audio. Picture quality displayed is 1080p/60hz.
All other formats including standard digital content can be viewed and heard without any issues.

My Current Set Up :
1) AV/ Receiver : NAD T775HD (capable of decoding Dolby TrueHD)
2) Blu Ray Player : NAD T557
3) Speakers : PSB Imagine Series
4) HDTV : Panasonic Viera TH-P54V20A (This is an Aussie Model)

Connections :
I have kept this fairly simple. 2 HDMI leads and 1 optical cable.
1) “HDMI OUT” from Blu Ray Player to “HDMI IN” NAD Receiver .
2) “HDMI OUT” from NAD Receiver to the TV “HDMI IN”. Panasonic offers 4 HDMI ports . I have used HDMI 1.
3) In addition I have used an optical cable from the TV out to the Receiver to be able to listen the broadcasts through the receiver.
4) The bluray player is set as pass through for HDMI content for the receiver to decode. Picture quality is set to auto.


My Observations:
1) Dolby TrueHD audio can be heard through the receiver if the TV is turned off.
2) The audio output can also be heard upon switching the HDMI connection in the TV. As an example, if I were to use HDM I as the connection from receiver, I can only see the picture by selecting HDMI1 however upon switching HDMI from 1 to 2, 3, 4 audio comes through! Obviously when I switch to 2, 3, 4 there is no video as it is only set for HDMI 1.
3) Once the bluray player audio setting to PCM , audio comes along with video. The receiver does not decode audio at this setting and the digital logo cannot be seen.
4) Have changed the HDMI cable to isolate cable fault as a reason.
5) With my limited knowledge I would think this has something to do with the setting in the TV ?


Cheers,
Ashim

[MrBoylan]

Sorry for the delay. Actually I was thinking this is more likely to be a problem with the receiver, not the TV - I suspect that the HDMI/EDID handshake is getting messed up as it passes through the receiver to the TV and back tothe player. Specifically look in your receiver's set-up menus to see if there is an option to disable the HDMI AUDIO OUTPUT to the monitor. Some receivers have this setting and it can prevent this kind of HDMI/EDID problem. I checked your manual online and did not see such an option, but it's possible that it isn't documented. You could also try turning off the speakers on the TV itself (in the TV's audio menu) but I'm not convinced this will have any effect.

One last hail mary pass would be to try a different start-up order for your gear. Turn on the receiver first, then the player and then (after a delay of at least 15 to 20 seconds) turn on the TV. This way the initial HDMI/EDID handshake will happen between the player and receiver and this might work around the problem as the receiver correctly identifies its capabilities. If it does work around the issue, then you could program the start order and delays into a universal remote (using a macro or similar feature) or just remember to wait when starting up your system.

Your best bet is probably to cointact NAD and report the problem and see if they have any suggestions. I've tested a few of the US Panasonic TVs and had no such problem with Dolby TrueHD soundtracks, but we haven't tested any of the NAD gear.

Good luck and let us know if any of this helps!

-Chris