I've connected my Panasonic DMR-BWT720 Bluray/DVD player to my Onkyo TX-NR515 via HDMI, but when I play back Dolby Digital DVDs the Onkyo does not indicate a Dolby Digital source - it indicates PCM on the display.

Could someone confirm whether this is OK, and whether I have the sound settings on the Panasonic set to their optimum values for 5.1 audio? My current settings are:

Sound:
- Dynamic Range Compression: Off
- Downmix: Surround encoded
- Bilingual audio selection: M1
- Audio delay: 0msec
- Audio for HG/HX/HE/HL/HM Recording: 5.1-channel

Digital Audio Output
- PCM Down Conversion: On
- Dolby D/ Dolby D+ / Dolby TrueHD: PCM
- DTS/DTS-HD: PCM
- MPEG: PCM
- HE-AAC: PCM
- BD-Video Secondary Audio: Off

The amp indicates PCM because that's what you've set the player to give out!:



If you want the amp display to show the signal it is decoding then the BD player should be set like this:

Digital Audio Output
- PCM Down Conversion: OFF
- Dolby D/ Dolby D+ / Dolby TrueHD: Bitstream
- DTS/DTS-HD: Bitstream
- MPEG: Bitstream
- HE-AAC: Bitstream
- BD-Video Secondary Audio: Off[


The other settings are to do with how the Panasonic handle the sound from broadcast TV (Freeview) and other things you are asking it to record or pass through:

Sound:
- Dynamic Range Compression: Off
- Downmix: Surround encoded or stereo - it makes no difference to the HDMI output. The amp will take over sound decoding
- Bilingual audio selection: M1 - that's fine
- Audio delay: 0msec - if the sound is out of sync with the picture then this is used to correct that. Can't say what the 'right' number might be because it has to be set when looking at the effect through your system
- Audio for HG/HX/HE/HL/HM Recording: 5.1-channel - that's fine

Thanks for the reply. I should have clarified that I also tried setting the Digital Audio settings to Bitstream, but the receiver still didn't indicate Dolby Digital (i.e. it still indicated PCM),

From a 5.1 audio quality point of view, would you recommend that I use Bitstream or PCM on the Panasonic?

Bitstream for 5.1

Also check the Audio output of the amp, it should be on Auto - the options are normally, PCM, DTS, Ext and Auto....

We need to clarify here whether you were watching a DVD/Blu-ray with DD sound, or was this when watching TV. The reason is that the source signals determine what the player has to deal with, and that ultimately affects the what the receiver sees and (if appropriate) decodes. So, what was it you were watching?



As a general reply though, Bitstream sends the raw signal from the player to the amp. If the signal is in digital stereo (PCM) then the amp will report PCM. If the signal is in Dolby Digital format then the amp will display DD and the number of active* channels.

PCM via HDMI can be anything from mono, stereo, or full 5.1 surround. The player can decode the signal instead of the amp doing it. HDMI will carry all the same information via PCM, and it will play out the same whether delivered as 5.1 in PCM or decoded by the amp itself from a Bitstream signal. The quality is just the same. The only noticeable difference is that the display reads PCM rather than DD/DTS/TruHD/Master.


[* 'active channels' means that even with the DD symbol illuminated, there's nothing to say that the source signal is using all of the speaker channels. DD can just as easily be in stereo (2.0) or even mono (1.0) as in 5.1]

Thanks for the explanation. I can confirm that I was playing back a music DVD on the Panasonic which indicated Dolby Digital on the packaging.

Deacon1972: when you say to set the Audio output of the amp to Auto - I'm not sure I understand what you mean. The Onkyo allows you to select a default Listening Mode for each Input Source and Signal Format (e.g. I could select a Listening Mode of "All Channel Stereo" for any "Analog/PCM/Digital" signal on the Panasonic source). Is it the Listening Mode that you're referring to. Unfortunately there's no "Auto" Listening Mode. There's a "Direct" Listening Mode, which is described as " audio from the input source is
output without surround-sound processing. The speaker configuration (presence of
speakers) and speaker distance settings are enabled, but much of the processing set via
the audio setup is disabled". Presumably that's not what you meant?

???

Page 59 of the manual explains it all, it's under " setting the incoming digital signal (fixed mode).

Looks if you have to navigate to the home menu then source setup.....

Fixed mode (auto) is what needs to be selected - Basically it decodes the digital signal automatically.

Ah OK, so I just need to check that Fixed Mode is OFF (i.e. that the format is detected automatically)?

From Chris Frost's post it also sounds like I can leave the Panasonic Digital Audio settings to PCM, as the end result (i.e. what I hear) should be exactly the same as if I'd selected Bitstream.

Yes, fixed off....

Select Bitstream if you want the amp to display the audio format, PCM will just show multichannel pcm or similar.

It can be complicated at first, it does get easier.....

Reading the manual for the Panasonic it does seem that it can send up to 7.1 surround in PCM over HDMI. So you could leave the output as PCM if you wish. Have a listen to both though. In PCM the Panasonic does the decoding, in Bitstream the Onkyo does. So there may be differences in the way the two do the job and one may sound better then the other. Or there may be no noticeable difference at all.

Sometimes you have to be careful as PCM is often used to refer to Stereo as opposed to multi channel surround even though it can be any number of channels.

Hmmm....now I'm confused....the options for Fixed Mode are:
(1) Off: The format is detected automatically. If no digital input signal is present, the corresponding analog input is used instead.
(2) PCM: Only 2-channel PCM format input signals will be heard. If the input signal is not PCM, the PCM indicator will flash and noise may also be produced.
(3) DTS: Only DTS (but not DTS-HD) format input signals will be heard. If the input signal is not DTS, the dts indicator will flash and there will be no sound.

Of these, it seems that (1) (i.e. OFF) is the one for automatic format detection. If I select PCM, the description above suggests that I'll only get 2-channel input signals. Have I misunderstood this?

Re. Bitstream vs PCM: My understanding from Chris's explanation above is that a PCM setting on the Panasonic would send a 5.1 signal to the Onkyo which had been decoded by the Panasonic, rather than Bitstream which would leave the 5.1 decoding to the Onkyo, but either way I'd get the right 5.1 output. Hence I'm unclear why I should definitely select Bitstream - is it because it's better to have the Onkyo doing the 5.1 decoding?

Apologies, I have edited my reply as I misread your post, cooking tea while replying .

Fixed mode needs to be off....

The amp will display the audio format when Bitstream is selected, the amp will show multichannel pcm or similar when PCM is selected.

Try Bitstream, then you will see by the amps read out that you are getting DD5.1, DTS, True HD or DTS HD MA .....

Having read the relevant section of the Onkyo manual online I agree that Fixed Mode should be set to OFF to allow auto selection of the input format. It seems that Fixed Mode ON refers to setting either PCM or DTS only as the input formats.

OK I seem to be making progress now....selecting Bitstream on the Panasonic has the advantage of the Onkyo showing the source signal format as you say, so now I see why it's the better choice. Now I need to sample some of these listening modes to see what fits best as a preset for each.

Many thanks for the input.

Sorry for the confusion earlier....glad you are making progress.

Listening modes:

Since most TV channel sound is stereo, then the best mode to use is Dolby Prologic II Movie. This will either detect the presence of Dolby Surround matrixed in to the stereo siignal and decode it to give a surround effect, or it will use its own processing to manufacture pseudo surround.

Freeview HD channels should show up as DD, but it's DD that could be stereo more often than it is 5.1 Not all of the channels broadcast DD5.1 all the time. So if it sounds like there's no centre or surround sound then that's the reason why.


Blu-ray and DVD movies - with the exception of older titles then you should find a lot of films have at least DD. You may need to check the disc menus and select DD or a HD audio version. Don't just presume that the disc will play the best sound.

Music Video discs..... it's anyone's guess. Check the set-up menu. Assume nothing. Stereo can be played back using DPL II Music or Movie. You could also play in 7ch stereo. There are DTS equivalents to the DPL modes. Or you could play it in stereo which means front L&R + sub only.

Any music dvds with 5.1 audio should be played straight.


For anything Bitstreamed in 5.1 (DD/DTS/Dolby True HD/DTS Master Audio) then STRAIGHT should be sufficient unless you're running 7.1 speakers. If you are then the Blu-ray Bitstream will either include 7.1 audio, or you can take a 5.1 sound and add ProLogic IIx to decode matrixed reach channel info or manufacture rear channel sound from scratch. DLP IIz does the same but for front height instead of rear.

Your amp has two different audio processing stages. The first is recognising the signal (Straight / DPL II etc). The second is Effects. This is the group of sound effects processing that includes Church, Stadium, Jazz etc. It's mostly echo and timing effects. They're a novelty at first, but rarely used much after.

I would try both ProLogic Music and ProLogic Movie options and see which you prefer. If your Onkyo is anything like mine the differences are quite noticeable. On my system there is a distinct tonal difference between the two modes.

In Movie the centre speaker is more prominent and there is less sound from the surrounds. In Music the centre is lower and it seems a bit more dialogue comes from the fronts as well. And there is more sound from the surrounds.

Personally I prefer the Music mode to Movie for TV listening but obviously your ears may prefer otherwise

I myself never apply any non Dolby listening modes, I prefer to playback everything in it's original state. I'll apply DPLII movie for certain TV dramas/series not in DD, content like Top Gear, music and the news I keep in stereo.

I listen to all 2 channel music in Pure Direct mode, DVDA, the few I have automatically playback the original track, for example DTS for The Eagles (HFO) and DTS 4.1/4.0 96/24 for Queens Greatest Hits 1&2.

For Bluray I'll check the languages/audio menu to make sure the highest quality soundtrack is selected, for example True HD, DTS HD MA or Dolby Atmos if and when available.

All you can do with listening modes is suck 'em and see, everyone is different in what they think sounds best to them.