Another PCM/Bitstream question

[buster6070]

Just wondering which one is best? I'm about to setup my new reciever "Harman Kardon AVR 3600" which supports the newest DTS-HD/Dolby HD, and just trying to decide. Should I setup my blu-ray to PCM or bitstream. I realize that if set to bitstream I may not here little things like menu pop-ups, etc. But will the sound not be as good? And if I do set my BR to PCM, how does my reciever process that? Does it auto detect PCM like it does Dolby Digital or will it just display Logic 7 like when I watch regular tv. Any help would be great, thanks.

 

[ljaggers]

Either Or

It is my understanding that neither is better than the other. If one is, I'll bet you will be hard pressed to hear the difference. I just purchased the H/K AVR 1600 myself & set my Blu-ray player to send bitstream to be processed by the receiver. Sounds great to me.

If you were going to decode the audio in the Blu-ray player and send PCM to the H/K it can receive it either through HDMI or the multi-channel analog inputs (depending on what outputs you have on the BR.) The AVR1600 will then display "PCM" & the sampling rate that is coming through. The receiver will not, however, display "Dolby True-HD" or "DTS-HD Master" (which is something I personally like to see.) Ultimately you shouldn't hear much of a difference.

P.S. Excellent receiver choice

 

[GlocksRock]

Bitstream does not support secondary audio stream i.e. picture in picture audio that would be used in something like a directors commentary, or movie extras. But if you don't care about that and want to see the TrueHD or DTS-HD Master audio lights on your receiver, then select bitstream. They should both sound exactly the same, the only difference that may exist is a slight variance in overall volume, which would only be a few db at most.

 

[AcuDefTechGuy]

Theoretically, they should sound identical, like Glocks says.

But receivers/BD players may differ in a variety of ways.

For me & my current setup, bitstream actually sounds better than PCM.

However, in the past with different processors, etc. and different setups, PCM sounded identical to bitstream.

So the moral of the story is to try BOTH ways and see which one sounds better to you.

The biggest advantage in bitstreaming to me is knowing "for sure" what sound I'm actually hearing.

For example, a lot of TrueHD movies have DD as the DEFAULT!

If you use PCM, you may be hearing the DD if you don't watch out.

If you bitstream, your receiver will say Dolby TrueHD or Dolby Digital.

 

[buster6070]

Thanks for the advice everyone. Reciever just came in, but I gotta go to work. First thing tomorrow though my old AVR is coming out and my new one is going in. Gonna try both PCM and bitstream to see if I can tell a difference. I don't usually watch the comments or extras so most likely will go with bitstream. I'll get back tomorrow with results. Thanks again.

 

[KASR]

I've always heard that it's better to let the player do the decoding as opposed to making the receiver do it - something about syncing...but I could be wrong (it's happened before).

 

[GlocksRock]

I'd much rather have the receiver do the decoding over the player, but that's just me.

 

[AcuDefTechGuy]

I'd much rather have the receiver do the decoding over the player, but that's just me.

Yeah, especially when your receiver is $1,500 and your BD player is $400.

I see early adds for BD players (Black Friday) for $99.

I bet these $99 BD players do a better job decoding than your $1,500 receiver.

I mean the high quality components in these players must be overwhelming.

 

[KASR]

Yeah, especially when your receiver is $1,500 and your BD player is $400.

I see early adds for BD players (Black Friday) for $99.

I bet these $99 BD players do a better job decoding than your $1,500 receiver.

I mean the high quality components in these players must be overwhelming.

"...contrary to what you might hear elsewhere, there's absolutely no sound-quality difference whether the decoding takes place in the receiver or the Blu-ray player. The common analogy is to "zipping" a file on your computer; it's the exact same file if you unzip it on another computer. The only real difference is that if you use onboard decoding on your Blu-ray player, you won't see the "Dolby TrueHD" or "DTS-HD Master Audio" lights on your receiver. That's because the receiver only knows it's receiving a linear PCM signal; it doesn't know how that linear PCM signal was previously compressed...." - source

 

[3db]

"...contrary to what you might hear elsewhere, there's absolutely no sound-quality difference whether the decoding takes place in the receiver or the Blu-ray player. The common analogy is to "zipping" a file on your computer; it's the exact same file if you unzip it on another computer. The only real difference is that if you use onboard decoding on your Blu-ray player, you won't see the "Dolby TrueHD" or "DTS-HD Master Audio" lights on your receiver. That's because the receiver only knows it's receiving a linear PCM signal; it doesn't know how that linear PCM signal was previously compressed...." - source

I wanna see the lights

 

[KASR]

I wanna see the lights

Yea, me too...I love that crap!

 

[AcuDefTechGuy]

"...contrary to what you might hear elsewhere, there's absolutely no sound-quality difference whether the decoding takes place in the receiver or the Blu-ray player. The common analogy is to "zipping" a file on your computer; it's the exact same file if you unzip it on another computer. The only real difference is that if you use onboard decoding on your Blu-ray player, you won't see the "Dolby TrueHD" or "DTS-HD Master Audio" lights on your receiver. That's because the receiver only knows it's receiving a linear PCM signal; it doesn't know how that linear PCM signal was previously compressed...." - source

Of course. All $100 BD players will sound just as good as any $5,000 receiver.

There's nothing wrong with that thinking.

I'm sure double-blinded studies have proven that and journals have been published.

But I'll just continue to let my $5,000 receiver do all the processing because it makes me sleep better at night.

 

[KASR]

Of course. All $100 BD players will sound just as good as any $5,000 receiver.

There's nothing wrong with that thinking.

I'm sure double-blinded studies have proven that and journals have been published.

But I'll just continue to let my $5,000 receiver do all the processing because it makes me sleep better at night.

Well, since the blu-ray isn't producing the sound it merely decoding and then transferring the information, I fail to see how it's doing a worse job than the receiver. Perhaps you can explain this phenomenon?

 

[AcuDefTechGuy]

Well, since the blu-ray isn't producing the sound it merely decoding and then transferring the information, I fail to see how it's doing a worse job than the receiver. Perhaps you can explain this phenomenon?

It has been published (The Audio Critic) that CD players, DACs, Amps, preamps, and wires pretty much do NOT create sounds of their own unless defective or bad SNR/distortion. Thus, they will sound pretty much the same.

However, speakers & processors/decoders DO sound differently from one another - even when VOLUME MATCHED.

Another fact is that not all players (BD) are the same in the way they implement the bass and overall sound.

For example, when my Denon BD player decodes the sound (DTS-HD/TrueHD) and outputs via PCM, there is significantly LESS bass than when my Denon receiver decodes the DTS-HD/TrueHD - volume matched via SPL meter.

Another example was with my Toshiba HD-XA1 player & HK receiver. When I watched The Matrix HD DVD, I compared the TrueHD sound decoded by the player and output via PCM to the bitstream of plain Dolby Digital decoded by my HK receiver.

Again, the plain DD bitstream (decoded by receiver) had significantly more bass than the Toshiba's internal TrueHD decoder - volume matched SPL.

Another example was comparing my Denon receiver + BD player vs. the computer's TMT3 software player's internal TrueHD decoder with the movie Transformers BD (1st movie).

Denon BD player decode ---> sorry a$$ bass.
Denon Receiver decode ---> sorry a$$ bass.

TMT3 HTPC decode ---> Totally Awesome a$$-kicking bass.

Theories are good as guidelines, but don't let them be the final answer to all.

Always try all the possible options and see which one gives you the best sound (especially Bass).

It's not difficult to change from PCM to Bitstream and vice versa.

 

[KASR]

It has been published (The Audio Critic) that CD players, DACs, Amps, preamps, and wires pretty much do NOT create sounds of their own unless defective or bad SNR/distortion. Thus, they will sound pretty much the same.

However, speakers & processors/decoders DO sound differently from one another - even when VOLUME MATCHED.

Another fact is that not all players (BD) are the same in the way they implement the bass and overall sound.

For example, when my Denon BD player decodes the sound (DTS-HD/TrueHD) and outputs via PCM, there is significantly LESS bass than when my Denon receiver decodes the DTS-HD/TrueHD - volume matched via SPL meter.

Another example was with my Toshiba HD-XA1 player & HK receiver. When I watched The Matrix HD DVD, I compared the TrueHD sound decoded by the player and output via PCM to the bitstream of plain Dolby Digital decoded by my HK receiver.

Again, the plain DD bitstream (decoded by receiver) had significantly more bass than the Toshiba's internal TrueHD decoder - volume matched SPL.

Another example was comparing my Denon receiver + BD player vs. the computer's TMT3 software player's internal TrueHD decoder with the movie Transformers BD (1st movie).

Denon BD player decode ---> sorry a$$ bass.
Denon Receiver decode ---> sorry a$$ bass.

TMT3 HTPC decode ---> Totally Awesome a$$-kicking bass.

Theories are good as guidelines, but don't let them be the final answer to all.

Always try all the possible options and see which one gives you the best sound (especially Bass).

It's not difficult to change from PCM to Bitstream and vice versa.

That actually makes quite a bit of sense - it might also explain why TrueHD didn't sound as good when decoded from my Toshiba HD-A20. Gonna flip the switch and see what happens. Thanks for the additional info!

 

[buster6070]

Using bitstream, I like the lights too. Unfortunatly experiencing some sound delay. Trying to figure out whats causing it as it doesn't seem gradual like I would expect. Thanks for everyones help.

 

[Shrivel]

I generally prefer the receiver to do the decoding, and I think the industry is probably gonna move in that direction exclusively. It doesn't make a lot of sense to include the extra expense of decoders in the players when a receiver can do it.

The one advantage that allowing the player to decode in my situation is the fact that my receiver (Marantz 5003) can't apply Audyssey equalization processing over the high res audio tracks that it decodes, only over PCM tracks. This is not a big deal to me, but it could certainly be to others.