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Can't get DD or DTS through HDMI, only PCM

18603 Views 24 Replies 9 Participants Last post by  Kilian.ca
Hey guys,


I've been racking my brain over this...reading through forums, scouring instruction manuals, etc... I need help!


Granted I'm pretty new to this surround world, I feel like my setup is correct - just not working. Here's what I'm working with:


I have a 5.1 speaker setup, a Sony BDP-S570 BluRay Player, and an Onkyo TX-SR309. I have the Blurray Player connected via HDMI directly into the receiver, with another HDMI cable connected from the receiver to my TV. I've gone through all the settings on the blurray player and it looks like it is fully ready to transmit DD and DTS signals. When I select a Bluray to watch I make sure the audio settings on the BD are correct (in the case of what I am testing now, it is set for DTS-HD Master Audio.) When the movie begins playing though, the receiver only seems to be reading in PCM audio, and not DTS as I feel it should be. What steps am I potentially missing here?


I've also gone through all the receiver setup options and can't seem to find any answers there either. From what I can tell it is fully ready to receive DTS or DD surround audio.


Any suggestions? Thanks!
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First, if your player is decoding the lossless track, then PCM is the best possible audio. It doesn't matter whether the player or the receiver does the decoding. The resulting PCM is the same either way.


As to why your player is doing the decoding rather than sending DTS-HD Master Audio to your AVR for decoding, we'll need to know the player's audio output settings. This is almost certainly a player setting issue. Also, are you getting multichannel PCM or just stereo?
You know, I think I actually figure it out. Continued reading through threads and found that someone suggested turning off the "BD Audio MIX Setting" on my particular bluray player. Bingo.


Suddenly DTS Master HD is an option and sounds WORLDS better.


I posted too soon.
But thank you!
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Yes, that's the player setting that usually causes a PCM output. Mix = On is the default.


But, again, PCM is the same quality as lossless decoded by your AVR. And PCM enables menu sound effects and other secondary audio. It may also facilitate room correction and other DSPs that some moderately priced AVRs cannot do when decoding lossless tracks themselves.


Sent from my ADR6400L using Tapatalk 2

Quote:
Originally Posted by NickRRood  /t/1416253/cant-get-dd-or-dts-through-hdmi-only-pcm/0_50#post_22142723


You know, I think I actually figure it out. Continued reading through threads and found that someone suggested turning off the "BD Audio MIX Setting" on my particular bluray player. Bingo.

Suddenly DTS Master HD is an option and sounds WORLDS better.

I posted too soon.
But thank you!

What you perceive as "world's better" is simply due to the "bitstream" audio being a few db louder.



As BIslander noted, the audio quality is the same either way.
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I disagree!


I bought a new Yamaha RX-V673 on Saturday to replace an Onkyo TX-NR616, returned after three weeks of aggravation with problems (another story, another thread!) and I was frustrated with it because it was only outputting PCM. After reading this thread, I had the Mix=On and changed the setting and now I'm outputting TrueHD from the BD Player (Sony BDP=580) and the difference is immediately much, much better.


Of course, this is with 10 minutes of playing before I had to leave for work this morning, but last night, I was on the brink of returning another receiver because it wouldn't do what it was supposed to.


Made me realize, too, that because of the Onkyo problems, I hadn't watched a BD movie in over three weeks!
^^

While I would never disagree with someone's personal expediences, the fact remains there is no difference between the PCM produced by player and receiver decoding. Lossless codecs are like zip files whose sole purpose is saving space on a disc. The decoders on all players and receivers unzip lossless codecs exactly the same way. They have to. Otherwise the outputs would not be lossless. So, perhaps the differences you hear are simply volume. Or, maybe you applied other processing to the PCM in your player, something like Dynamic Range Compression.



Sent from my ADR6400L using Tapatalk 2

Quote:
Originally Posted by BIslander  /t/1416253/cant-get-dd-or-dts-through-hdmi-only-pcm#post_22143193


^^

While I would never disagree with someone's personal expediences, the fact remains there is no difference between the PCM produced by player and receiver decoding. Lossless codecs are like zip files whose sole purpose is saving space on a disc. The decoders on all players and receivers unzip lossless codecs exactly the same way. They have to. Otherwise the outputs would not be lossless. So, perhaps the differences you hear are simply volume. Or, maybe you applied other processing to the PCM in your player, something like Dynamic Range Compression.

Sent from my ADR6400L using Tapatalk 2

+1/ PCM is the original data. The high def lossless codecs are just lossless codecs. To be lossless, by definition, when you decode them, you have to get the PCM that started.


I note JDSmoothie suggested there may be a volume difference between the output with bitstreamed lossless codecs and that with PCM from the player, and AFAIK it has been established beyond question that normal human beings uniformly will hear small differences in volume as increases in clarity, detail, etc. and likely never notice the volume difference. People constitute bad measurement devices!
It's entirely possible for the PCM to sound different than the bitstream if the 'mix' setting is enabled. Many players will downsample the output to regular Dolby Digital when the 'mix' setting is enabled.
^^

Some players use lossy when mixing secondary audio. But, not this player.


Sent from my ADR6400L using Tapatalk 2
I don't know too much about the technical side, but I do know what I like! Whether my Rx wasn't processing the PCM or recognizing it I have no idea, but when I changed the setting, I was getting TrueHD or DTS Master Audio where I wasn't before and it sounds a whole lot better!


This is not intended as an attack, but sometimes I feel people put too much importance on facts and figures when all that matters is whether someone is happy with what they're hearing.

Quote:
Originally Posted by Guindalf  /t/1416253/cant-get-dd-or-dts-through-hdmi-only-pcm#post_22146826


I don't know too much about the technical side, but I do know what I like! Whether my Rx wasn't processing the PCM or recognizing it I have no idea, but when I changed the setting, I was getting TrueHD or DTS Master Audio where I wasn't before and it sounds a whole lot better!

This is not intended as an attack, but sometimes I feel people put too much importance on facts and figures when all that matters is whether someone is happy with what they're hearing.

Facts are good. Nobody can tell you what to hear, but there's nothing wrong with knowing the underlying facts. If yit leads a person to assess whether, like all other human beings, they are subject to biases that comme from all over the place (including subconscoius biases that require double blind testing just to figure out if a pill really reduced pain) that's okay too.
Ok, so explain to me why my Sony BDP says it has options to output "Dolby Digital" or "DTS" or "Downgrade PCM" and the manual says "only enable PCM if your receiver is not capable of decoding DD or DTS"?

Quote:
Originally Posted by Guindalf  /t/1416253/cant-get-dd-or-dts-through-hdmi-only-pcm/0_50#post_22147877


Ok, so explain to me why my Sony BDP says it has options to output "Dolby Digital" or "DTS" or "Downgrade PCM" and the manual says "only enable PCM if your receiver is not capable of decoding DD or DTS"?

Well .... unless I missed it, the word "only" is not mentioned in the manual, rather simply that you would use PCM if the AVR cannot decode the audio and DD if it can, as most folks prefer to see the words DD/DTS on their front panel rather than seeing "Mult CH In". There's no implication that one format is better than the other.

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Really?


I'd say those instructions are pretty clear. The word "only" may be implied rather than stated, but to most, this would be read as 'only".


The word "Downmix" clearly suggests that it's an inferior option.

Quote:
Originally Posted by Guindalf  /t/1416253/cant-get-dd-or-dts-through-hdmi-only-pcm#post_22147877


Ok, so explain to me why my Sony BDP says it has options to output "Dolby Digital" or "DTS" or "Downgrade PCM" and the manual says "only enable PCM if your receiver is not capable of decoding DD or DTS"?

You do understand that everything recorded in digital that's not SACD is PCM? That PCM is the original, native recorded "sound" and that the lossless codecs take PCM, reduce the data load, then allow reconstruction back to PCM? It's not possible AFAIK for the zipped and unzipped system to be better than the original recording . . .
I have a Sony 770. In the manual, the Dolby Digital vs. Downmix PCM options refer to Coax/Optical output, so downmix (NOT downgrade) implies (as in normal use) channel reduction to 2.0 (stereo). There is a similar set of options for DTS for Coax/Optical. Coax/Optical can only carry max. stereo PCM, not multi-channel PCM. All this is irrelevant for the above scenario with HDMI connection.


The set of options for HDMI are Auto or PCM.


That aside, I'm puzzled why the volume difference between PCM and bitstream which seems to happen in the Onkyo. Why should a zipped and upzipped stream have different volume?

Quote:
Originally Posted by Kilian.ca  /t/1416253/cant-get-dd-or-dts-through-hdmi-only-pcm#post_22148898


I have a Sony 770. In the manual, the Dolby Digital vs. Downmix PCM options refer to Coax/Optical output, so downmix (NOT downgrade) implies (as in normal use) channel reduction to 2.0 (stereo). There is a similar set of options for DTS for Coax/Optical. Coax/Optical can only carry max. stereo PCM, not multi-channel PCM. All this is irrelevant for the above scenario with HDMI connection.

The set of options for HDMI are Auto or PCM.

That aside, I'm puzzled why the volume difference between PCM and bitstream which seems to happen in the Onkyo. Why should a zipped and upzipped stream have different volume?

That's a really interesting question. Maybe Filmmixer or soembody else in the biz understands how that happens. I assume it's anAVR anomaly, but IDK. Makes no sense to me, but I accept that it happens becuase it's been reported by reputable folks. Many players use the lossy stream if they are set to play the commentary etc. directly. Might be possible to detect the difference between the higher bitrate lossy used on BD and the original PCM/lossless stream, at least in some circumstances . . . .
Guindalf, as you have acknowledged, you know little about the technical side. Perhaps you can accept the information from the several posters here who do have that knowledge, and then try to figure out why your experience is different. Is the volume simply louder? Studies have shown people tend to believe louder is better. Have you applied settings in your player that modify the PCM differently than your AVR? The use of DRC would be something that would account for an audible difference. There are lots of reasons why bitstreaming lossless to your AVR may seem to sound better to you. But, that doesn't mean bitstream is higher quality, which is what your position seems to be.


And please don't take your interpretation of implications in a user manual as meaningful technical distinctions. Downmix has a specific meaning - reduction in the number of channels - and in the context of that part of the manual, it is talking about sending stereo PCM instead of encoded multichannel audio because optical and coax connections cannot support multichannel PCM. Even with that difference, the stereo downmix of a lossless source would be higher resolution audio, just not discrete 5.1. For movies, most people would prefer the lower resolution DD 5.1 or DTS output because they are mixed for surround. But, with a concert, many might actually find the high resolution stereo output sounds better than lossy multichannel. And, with concerts, applying PLII to a stereo source often produces the same surround experience as the 5.1 mix, which generally won't have specific surround channel effects.
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