Question about DTS HD Master audio

How is your Sony player set up? It might be outputing PCM instead of Bitstream.

Or it could be outputting a lossy core audio, again depending on setup.

Are you using an HDMI cable to connect your BDP to your AVR? If so, check your audio settings on the Sony. Make sure you do not select the PCM options. The AVR should read DTS MA (or similar) when you have the settings right.

Double check your player and make sure that it is capable of playing higher rez format. If not, PCM is just as good.

I have a Sony 570 and the setting you're looking for is called BD Audio Mix on the 570. Set that to "Off", which sounds backwards but it's what the manual says.

If you want to hear the sound effects that are provided in the menus or the secondary audio track(s), you have to turn mix on. When you turn mix on, the player has to output PCM. The receiver won't show either Dolby or DTS indicators because that's not what it's getting -- it's getting PCM. The receiver has no way to know what's actually on the disc.

In order to do the mixing, the player internally decodes the audio from the disc into PCM and mixes it with the audio used for the menu. The player then has no choice but to output the resulting PCM: the player doesn't have the computational power (or the license) to recreate either DTS or Dolby high-def compressed audio bitstreams from the mixed audio.

It's not going to change how the soundtrack sounds. Either way, PCM or bitstream, you should get the same sound quality. The difference is where the decoding is being done. When you decode at the player, the player sends multichannel PCM to the AVR and all the AVR knows is that it is receiving some sort of multichannel PCM. It doesn't know which codec that multichannel PCM came from originally, which is why there is no display of a particular codec.

As pointed out, what WILL change if you pass bitstream instead of PCM, is that some of the audible menu beeps and clicks that you might have heard when navigating discs' menus, when passing PCM, will no longer be there.

Using bitstream also disables "secondary audio" which is used by PIP "Bonus View" options on some discs.

Some players, especially when they mix in the menu sounds and secondary audio channels, only output standard definition LPCM instead of high definition. Whether or not you can actually hear that difference is arguable.

There is no benefit to decoding in the AVR instead of the player, although some people like seeing the lossless codec on their AVR displays. You get the same PCM regardless of where the decoding is done and the AVR handles the rest of the processing (bass management, EQ, etc) either way.

In fact, there may be advantages to decoding in the player. You can mix in secondary audio for menu sound effects and PIP commentary tracks with player decoding. And, some AVRs lack the processing power to apply room correction or other DSPs when doing lossless decoding. So, in those circumstances, player decoding is better.

But, again, the PCM produced is the same no matter where the track is decoded.

Many players will use the lossy core for mixing with secondary audio, so it's not a given that decoding in a player is just as good as AVR.

Those players have settings that allow them to decode lossless tracks without secondary audio. I am not aware of any halfway recent player that cannot decode lossless to produce the exact same PCM as a receiver.

I do not know how with current generation of players, but two years ago NONE of players on the market were able to mix secondary audio with lossless tracks. So if you want to hear lossless either in PCM or native mode you had to disable all sound effects in player.

PS3s, Samsungs, LGs, and many Sony players will mix secondary audio when decoding lossless. That's always been the case with those players. In fact, most of them don't even have SA settings - there's no way to turn off effects audio - if you decode in the player you get whatever effects audio is present. Panasonics, Pioneers, and Oppos have the lossy limitation when mixing secondary audio.

But, it appears I have not been clear in making my point. I am saying there's no advantage to decoding in a receiver since you can get the exact same PCM when decoding in any player. There are also advantages to player decoding. Secondary audio is one of them. While it is true that some some players use the lossy track when mixing in effects, the only way to get SA is with player decoding. If you have a player with the lossy limitation, you can still get lossless decoding by turning SA off. The other potential advantage to player decoding is with receivers that lack the processing power to apply room correction or DSPs when decoding lossless tracks.

This is not the case with all players. But in those that re-encode S.A. it's usually to lossy DTS.

Of course it is. The original soundtrack must be decoded by the player in order to mix in the secondary audio. The fact that player is decoding the soundtrack on the disc may be transparent to the user who selects an output option such as re-encode. But, it happens nonetheless.

Players with a specific re-encode option mostly output DTS. But, players such as Panasonics, that have an SA option, re-encode with the original type - TrueHD as DD 5.1 and dts-MA as DTS.

Here's the point: if you bitstream lossless codecs to an AVR with lossless decoders, you cannot get secondary audio.

It's not a matter of DSP power, it simply would serve no purpose to re-encode lossless audio since HDMI handles PCM just fine.

The new Oppo 93/95 use HD audio when mixing secondary audio.

What??? You aren't going to watch the PIP descriptions of how scenes were developed while you're also watching the movie? Horrors! all that wasted effort by the producers!!!

Only a few BD discs include this feature, but it can be interesting at times.


In principle, you shouldn't be able to hear the difference between a high-bitrate DD or DTS soundtrack and the lossless equivalent. Both companies put a lot of work into the psychoacoustics involved in their lossy compression algorithms. As the bitrate goes down, there are more differences, of course, which eventually might produce audible effects.


You're quite welcome, of course.

Apart from that, letting the AVR decode and display the input codec also eliminates the chance of accidentally getting the wrong audio track from the player. Not all BD discs will default to lossless audio, and being able to see it on your AVR can be a help.

There are some receivers, such as the expensive Marantz sr7002 and Marantz sr8002, that can either decode DTS-HD MA/TrueHD or apply Audyssey. These receivers lacked the processing power required to decode HD audio and apply Audyssey.

By having the player output pcm, these Marantz receivers had no problem with applying Audyssey just as you said.

The Marantz AV8003 pre/pro that I have (it's the predecessor to their current AV7005) has the same limitation: decode HD audio or use Audyssey, but not both.