Player decoding or Receiver decoding, that is the question

[EWL5]

Originally Posted by aramis109

Hrm, interesting. The +15 vs +10db must not be an issue with the PS3, as I certainly have no lack of bass. During playback of DVD's/legacy codecs, I've switched back and forth and can find little to no difference, and none in the LFE department.

That is because the PS3 outputs a fullrange PCM signal after decoding. There is no option to select LARGE or SMALL speakers (it assumes all speakers are large and lets your AVR/prepro handle bass management). As stated in the first post, as long your AVR/prepro offers the nominal +10dB boost, you should be ok.

[EWL5]

Originally Posted by Ricshoe

This has been debated to death.

https://forum.blu-ray.com/showthread...light=decoding

But good write-up, just the same.

I realize that but I was never satisfied with speaking in "general terms." I tried to include specific issues and a hypothetical situation where decoding in either the player or the AVR/prepro would result in identical output.

Edit: Let me also add that although Sir Terrence and I share the same view that all decoders should be the same, I've gone a little further to explain why some users feel their AVR/prepro is doing a better job.

[aramis109]

Originally Posted by EWL5

That is because the PS3 outputs a fullrange PCM signal after decoding. There is no option to select LARGE or SMALL speakers (it assumes all speakers are large and lets your AVR/prepro handle bass management). As stated in the first post, as long your AVR/prepro offers the nominal +10dB boost, you should be ok.

Ah, nice. Thanks for the explanation.

[BIslander]

Originally Posted by aramis109

Hrm, interesting. The +15 vs +10db must not be an issue with the PS3, as I certainly have no lack of bass. During playback of DVD's/legacy codecs, I've switched back and forth and can find little to no difference, and none in the LFE department.

Originally Posted by EWL5

That is because the PS3 outputs a fullrange PCM signal after decoding. There is no option to select LARGE or SMALL speakers (it assumes all speakers are large and lets your AVR/prepro handle bass management). As stated in the first post, as long your AVR/prepro offers the nominal +10dB boost, you should be ok.

I believe the PS3 actually outputs an LFE channel that is the same level as the other channels, which makes it 10db low. (LFE is designed to be played 10db louder than the other channels.) The same is true of an uncompressed PCM track on a disc. LFE is recorded and sent 10db lower than the proper playback level.

In both of those cases, the digital software in the receiver knows that it needs to boost LFE by 10db. (The same thing happens with receiver decoding, btw. LFE is always recorded 10db low. The AVR does the decoding and then does the needed boost.) If bass management is engaged in the processor, then LFE gets dropped even further to make room for the redirected bass and the subwoofer output (LFE + redirected bass) will be boosted by 15db. With digital, all of those adjustments are transparent to the user. The software takes care of everything. Receivers don't even offer a digital subwoofer boost because it should never be needed.

Analog transmission is different. The end user has to apply the subwoofer boost in the receiver or at the sub itself.

[EWL5]

Thanks for moving it to the sticky. Hoping to hear from Sir Terence eventually...

[welwynnick]

I've been hearing many people say two things about bitstreaming to amplifiers:

1. Onkyo owners in particular often say how bitstream to their amplifiers sounds better than LPCM over HDMI. Flawed theory is irrelevant, there are clear differences to be heard.

2. Others say that they cannot sound different, as decompression of the bitstream is lossless, and the bits are the same in both cases. If some hears a difference, it must be because levels aren't matched, etc.

My view has alway been that it depends on the way the amplifier works, and we don't know enough to say for sure. Only having a DD?DTS receiver, I was really looking forwards to hearing thes differences (or not) for myself. I recently borrowed an Onkyo PR-SC886 from very good friend, "Mad Mr H". pooling his equipment and mine, I had the following kit to play with:

Players:
Denon 3800BD
Samsung BDP1200
LG BH200
Pioneer DV989
Processors:
Lexicon MC12V4
Onkyo [FONT='Verdana','sans-serif']PR[/font]-SC886
DVDO EDGE
Amplifiers:
Sony DA9000
Magnum 125 stereo
Lynx monoblocks
Speakers:
Final electrostatics 5.1
Acoustic Energy Aegis Evo3 5.1
Acoustat hybrid electrostatics
Final, AE & Rythmik Servo Subs.
Displays:
JVC DLA-RS1X
Panasonic TH42PZ70

I figured the Onkyo would perform with BD sound tracks, but I also wanted to see how it compared with a top quality processor when playing CDs and DVDs (which was not very well). It was also a good opportunity to compare both PQ and SQ ofvarious players, using the DVDO where necessary to shore up the de-interlacing. But the focus for me was to compare player and amplifier decoding, and I looked at these combinations of tests:

PQ: Denon 3800 vs LG BH200
SQ: Denon 3800 vs LG BH200 by HDMI LPCM
SQ: 3800 into SC886 analogue vs HDMI LPCM
SQ: 3800 into SC886 LPCM vs bitstream
SQ: 3800 into SC886 analogue vs 3800 into MC12 analogue
SQ: 3800 into SC886 HDMI vs BH200 into MC12 DTS spdif

I used a Radio Shack analogue sound level meter to set the speaker levels, and an Eye One Display LT to calibrate the displays as far as I could. This is what I found. With bitstream, it was like listening to a different soundtrack. All the sounds were there, the frequencies and the dynamics etc, but with LPCM the 886 was seemingly throwing all these high resolution sounds at you without making sense or order out of them. The Lexicon seemed to know how to organise the music it was reproducing and make it convincing, but it didn't have HBR capability.

With bitstream into the 886, everything seemed to come to life. The sounds were the same, but it was like it was happening in front of you, instead of being an accurate reproduction. A wall of sound became a room full of tangiable sources.

I guess I could be deluding myself, but I don't think theres any question about it to my mind, its hardly difficult to spot. When I first put on an LPCM blu-ray thinking it was TrueHD, I come away with what I thought was a null result, and I was happy just to have the answer that I wanted. It wouldn't have stopped my getting an amp or processor with HBR decoding, I just wouldn't have cared so much. Not any more.

This is quite a revelation, and the 886 is sounding fine. In subective terms its up with the best stereo systems that I remember so fondly, its that good. Its left any DD/DTS based system behind in my opinion. My goodness, I've got to go and listen to all my BDs again. Heck, why did I bother buying all those cheap HD DVDs with their infernal dolby digital plus soundtracks? Damn. This is the most exciting day I've had for -er- yonks.

At first I thought I wasn't yet hearing everything that was on the disc. Well, I think I made a big step in that direction. I have no doubt that I could spot this reliably with blind testing, and will see if I can sort something out. However, this clearly show to me that all those people who insisted that they heard better audio from bitstream were not imagining it. In many cases it could be that they were simply listening to the film at higher volume, and I had to frop the volume down about 3 dB to compensate for what the amplifier was doing with bitstream (which I thought wa a bit of a cheat).

But no, the answer is clearly that bitstream does make a difference with the equipment that I was using. of course it could be that a different receiver or processor would have different processes when decoding and converting bitstream, and the result could be quite different. For example, the Onkyo suffers from moderate jitter over HDMI in the recent HiFi New & record Review tests, and recent Pioneer receivers were much less sensitive. It could be that they would not show an audible improvement in going to bitstream - it would be useful to get some feedback there. Furthermore the Denon 3800 seemed to suffer less with LPCM output than the LG BH200, so I have to assume that it has a better engineered and less jittery or noisy LPCM output. So I think the answer does depend on the equipment being used, but in simple terms it is clear that bitstream is better.

regards, Nick

[crackinhedz]

was this "test" under double blind conditions?

...so how could it be truth/fact?


And even then, youd have to pretty much be able to switch back and forth on the fly because your auditory/echoic memory lasts for only seconds.

[Tok]

Are you aware of the DolbyTrueHD issue with Onkyo and some other receivers that decode it?

The DRC is defaulted to AUTO on the Onkyo AND most every TrueHD track is set limit the DRC to midnight mode in the bitstream flags. When I turn DRC OFF on the Onkyo, I hear no difference between the 805 decoding bitstream from the BD35 or the PS3 and the BD35 sending LPCM on the same tracks. Note you have to set DRC to OFF on the PS3 also BUT the PS3 remembers the setting between power cycles. The Onkyo does not.

[sheedoe]

Thanks for taking the time to do the tests. I have always wondered the same thing. I think the components that decode the hi-res audio makes a difference in the sound output. Here's a quote from the Onkyo 885 review @ ultimateAVmag.
"I wanted to start by testing the Dolby TrueHD decoding of the pre/pro vs. decoding in an HD DVD player, so I popped in Harry Potter and the Order of the Phoenix on HD DVD and watched the climactic battle between Dumbledore and Voldemort. Just as I have discovered in the past, decoding in the pre/pro was the better option. The soundtrack had a bit more punch and depth compared to the internal decoding of the HD DVD player."

[welwynnick]

Originally Posted by crackinhedz

was this "test" under double blind conditions?

...so how could it be truth/fact?

And even then, youd have to pretty much be able to switch back and forth on the fly because your auditory/echoic memory lasts for only seconds.

I'm not aware that there have been any DBTs to show that it doesn't make a difference.

We ll know that nody does DBT tests on the user community. Even doing single blind tests was difficult and time-consuming, but they were valid and they were repeatable. I've been testing for two weeks now, and there are some interesting patterns emerging which I think Blu-ray enthusiasts would like to hear about. It will take some time to write up but there's a lot to talk about.

Other forums are open-minded but Blu-ray.com has been peculiarly polarised on this issue. There are the "bits-are-bits" people who say that there can't be any difference because of the theory that they choose to believe. And there are the amateur subjectivists who say they can hear a difference, even though it may be explained scientifically by other differences.

I have resolutely stood in between these diametrically-opposed views, and always insisted that there MAY be a difference, but it depends on how the receiver works. It could be that with different receivers or processors, the result could be quite different, and there are at least two reasons to explain that. However, I can say with confidence that with the particular equipment I had at my disposal, amplifier decoding DID make a difference. Until this week I was sat on the wall, but now there is no doubt about it in my mind. I would be happy to demonstrate this to any one who would care to come round and listen, and I'm hoping to arrange a few sessions shortly.

Originally Posted by CraigW

Are you aware of the DolbyTrueHD issue with Onkyo and some other receivers that decode it?

The DRC is defaulted to AUTO on the Onkyo AND most every TrueHD track is set limit the DRC to midnight mode in the bitstream flags. When I turn DRC OFF on the Onkyo, I hear no difference between the 805 decoding bitstream from the BD35 or the PS3 and the BD35 sending LPCM on the same tracks. Note you have to set DRC to OFF on the PS3 also BUT the PS3 remembers the setting between power cycles. The Onkyo does not.

Do you hear a difference with the DRC turned on?

Presumably that would make TrueHD sound worse on bitstream?

Nick

[crackinhedz]

Originally Posted by welwynnick

Other forums are open-minded but Blu-ray.com has been peculiarly polarised on this issue.

what makes other forums open minded and bluray.com polarized? ...simply because they do not agree with you? Or because they need more to go on than just opinion and speculation?

I'm not aware that there have been any DBTs to show that it doesn't make a difference.

exactly. I have not heard of one instance where someone did a double blind listening test for bitstream vs. lpsm...instead its just folks who say "oh yeah, bitstream is better because I can hear a difference." Which may be true, but...

I commend the long work you put into the "test"...but when these "tests" are not under the right conditions, they become biased and flawed. Which makes them unreliable at best.

I guess you could call me cynical. If you were to conduct a more scientific approach to this subject I would be more inclined to listen. Simply sitting on the couch comparing tracks does nothing for me. You must remove all bias beforehand.

[EWL5]

Originally Posted by welwynnick

I'm not aware that there have been any DBTs to show that it doesn't make a difference.

We ll know that nody does DBT tests on the user community. Even doing single blind tests was difficult and time-consuming, but they were valid and they were repeatable. I've been testing for two weeks now, and there are some interesting patterns emerging which I think Blu-ray enthusiasts would like to hear about. It will take some time to write up but there's a lot to talk about.

Other forums are open-minded but Blu-ray.com has been peculiarly polarised on this issue. There are the "bits-are-bits" people who say that there can't be any difference because of the theory that they choose to believe. And there are the amateur subjectivists who say they can hear a difference, even though it may be explained scientifically by other differences.

I have resolutely stood in between these diametrically-opposed views, and always insisted that there MAY be a difference, but it depends on how the receiver works. It could be that with different receivers or processors, the result could be quite different, and there are at least two reasons to explain that. However, I can say with confidence that with the particular equipment I had at my disposal, amplifier decoding DID make a difference. Until this week I was sat on the wall, but now there is no doubt about it in my mind. I would be happy to demonstrate this to any one who would care to come round and listen, and I'm hoping to arrange a few sessions shortly.

Do you hear a difference with the DRC turned on?

Presumably that would make TrueHD sound worse on bitstream?

Nick

Originally Posted by crackinhedz

what makes other forums open minded and bluray.com polarized? ...simply because they do not agree with you? Or because they need more to go on than just opinion and speculation?


exactly. I have not heard of one instance where someone did a double blind listening test for bitstream vs. lpsm...instead its just folks who say "oh yeah, bitstream is better because I can hear a difference." Which may be true, but...

I commend the long work you put into the "test"...but when these "tests" are not under the right conditions, they become biased and flawed. Which makes them unreliable at best.

I guess you could call me cynical. If you were to conduct a more scientific approach to this subject I would be more inclined to listen. Simply sitting on the couch comparing tracks does nothing for me. You must remove all bias beforehand.

Guys, you may be interested in the following thread I started in AVS:

http://www.avsforum.com/avs-vb/showt...1066645&page=1

It is double blind and I had FilmMixer (soundtrack mixer insider) agree with me concerning the results.

Edit: Anybody feel it would be a good idea for me to copy the first post over to Blu-ray.com either as a new thread or to an existing discussion?

[crackinhedz]

Originally Posted by EWL5

Guys, you may be interested in the following thread I started in AVS:

http://www.avsforum.com/avs-vb/showt...1066645&page=1

quick question?

...so you compared the optical connection vs. the multichannel analog connection? ...not sure how this is relevant?

Optical will only provide 2.0 stereo Lossless. Were you comparing multichannel and two channel? ...sorry if im misunderstanding the comparison.

[EWL5]

Originally Posted by crackinhedz

quick question?

...so you compared the optical connection vs. the multichannel analog connection? ...not sure how this is relevant?

Optical will only provide 2.0 stereo Lossless. Were you comparing multichannel and two channel? ...sorry if im misunderstanding the comparison.

No, I was comparing the DTS "core" of Master Audio over optical (this is the max it can do) vs the Master Audio over analog. It is not possible to select "core" of MA or HR as a choice in any audio menu of a BD video. Otherwise I would have compared "core" over analog vs MA over analog for a fairer comparison.

Does this make sense?

[crackinhedz]

Originally Posted by EWL5

Does this make sense?

gotcha.

...So your conclusion is that Lossless and Lossy are indistinguishable? Let alone bitstream vs LPCM...interesting.


Now may I ask, how long in between switching from lossless to lossy did it take you?

Was the multichannel analog audio compensated (spl) using the players internal speaker adjustments as well as adjusting for optical using the Rotel speaker adjustments? (In essence, to compensate for the different DAC's being used in both scenarios?)

[EWL5]

Originally Posted by crackinhedz

gotcha.

...So your conclusion is that Lossless and Lossy are indistinguishable? Let alone bitstream vs LPCM...interesting.

Yes, that was my conclusion. Controversial but backed by industry insiders and the now famous Home Entertainment Magazine "expose."

Originally Posted by crackinhedz

Now may I ask, how long in between switching from lossless to lossy did it take you?

I would play one track for about 30 sec followed by the track again for another 30 sec. Remember, I was not the test subject (my guests were). I would mix it up to guarantee against bias (ie. sometimes play lossless followed by lossless, etc.)

Originally Posted by crackinhedz

Was the multichannel analog audio compensated (spl) using the players internal speaker adjustments as well as adjusting for optical using the Rotel speaker adjustments? (In essence, to compensate for the different DAC's being used in both scenarios?)

Yes, the multichannel analog output was level matched to the optical output to within .5 dB. Even the crossover for both the AVR and the Denon 3800 were set at 80 Hz (this ability to set crossover is currently unique to the Denon 3800 and the Marantz 8200 BD players). I tried to make it as fair as possible when different DAC's are being compared (ie. during the "core" vs MA comparison). TrueHD vs DD comparisons were solely done using the analog outputs, so same DAC's were used in both cases.

I tried to make it as fair as possible. As my ABX results showed, my guests could not reliably tell lossless from lossy!

[crackinhedz]

Originally Posted by EWL5

Yes, that was my conclusion. Controversial but backed by industry insiders and the now famous Home Entertainment Magazine "expose."

I would play one track for about 30 sec followed by the track again for another 30 sec. Remember, I was not the test subject (my guests were). I would mix it up to guarantee against bias (ie. sometimes play lossless followed by lossless, etc.)

Yes, the multichannel analog output was level matched to the optical output to within .5 dB. Even the crossover for both the AVR and the Denon 3800 were set at 80 Hz (this ability to set crossover is currently unique to the Denon 3800 and the Marantz 8200 BD players). I tried to make it as fair as possible when different DAC's are being compared (ie. during the "core" vs MA comparison). TrueHD vs DD comparisons were solely done using the analog outputs, so same DAC's were used in both cases.

I tried to make it as fair as possible. As my ABX results showed, my guests could not reliably tell lossless from lossy!

Very interesting.

...one more question? are/were your test subjects aware of Lossless, Lossy, TrueHD, LPCM, Bitstream etc? ...in other words, did they have any inclination of what they might be listening to or listening for? ...for instance, my wife would have made a great test subject...she's oblivious to electronics.


And the only reason I ask more questions is because I like to see how sound your argument is. Seems like you have done a pretty thorough job.

Like I said in a previous post, I'm a very cynical person. Agnostic if you will.

[crackinhedz]

I would play one track for about 30 sec followed by the track again for another 30 sec.

I meant, how long in between the switch did it take you to go from lossless to lossy, vice versa?

...as echoic memory can play a detrimental part to audio comparison. Although this idea is also debatable.

[welwynnick]

Originally Posted by crackinhedz

what makes other forums open minded and bluray.com polarized? ...simply because they do not agree with you? Or because they need more to go on than just opinion and speculation?

exactly. I have not heard of one instance where someone did a double blind listening test for bitstream vs. lpsm...instead its just folks who say "oh yeah, bitstream is better because I can hear a difference." Which may be true, but...

I commend the long work you put into the "test"...but when these "tests" are not under the right conditions, they become biased and flawed. Which makes them unreliable at best.

I guess you could call me cynical. If you were to conduct a more scientific approach to this subject I would be more inclined to listen. Simply sitting on the couch comparing tracks does nothing for me. You must remove all bias beforehand.

I don't know what's different about this forum, but many people seem to take their opinons from those who claim to know what they're talking about, rather than being a bit more scientific (which I am!) and learning and understanding things for themselves. Unfortunately this is a complicated question that I've been endeavouring to unravel for a year or two, and I've only made some practical progress in the last few days. I've been reporting things on a day-by-day basis elsewhere, so there's a documented record, and this is quite pertinent.

Firstly, there's no reason why bitstream should sound the same as LPCM. The digital audio replay architecture is different, and that means the sound may be different. I'd better explain that, quick.

A digital audio signal has two elements - a data stream and a timing stream. Both of these end up at the DAC to create the analogue audio signal, and both need robustness and fidelity.

These streams are quite distinct, and take different critical paths:
The data stream starts at the disc, and ends up at the DAC.
The timing stream starts at the master clock, and also ends up at the DAC.

The bitstream decoding process only affects the data stream, and I think we are all pretty confident that that is lossless, so the DAC is receiving the right data, whichever decoding architecture is used.

However, this architecture MAY affect the path of the timing stream . This isn't necessarily the case, but my experience with the Onkyo suggests that it is. With LPCM, the clock is in the transport, and the path takes the HDMI connection to the receiver and too the DACs. This is a tortuous path, and is full of degradation - like toslink but worse. With bitstream, there's no clock associated with the data because its compressed, and the clock is regenerated in the amplifier, just as it is with DD and DTS. This places the clock right next to the DAC, with robust and direct connection, which is ideal. This doesn't eliminate interference, noise and jitter, but its a very big help.

So with bitstream there is an opportunity to minimise jitter, though this is only achieved if the amplifier doesn't generate its audio clock from the players video clock, in the same way it does with LPCM. For ayear, I've never known which it was, but I think that question has now been answered in my mind, now. Of course, my observations may not apply to other amplifiers, like Pioneers, which have different architectures. I'm itching to find out....

Nick

[EWL5]

Originally Posted by welwynnick

I don't know what's different about this forum, but many people seem to take their opinons from those who claim to know what they're talking about, rather than being a bit more scientific (which I am!) and learning and understanding things for themselves. Unfortunately this is a complicated question that I've been endeavouring to unravel for a year or two, and I've only made some practical progress in the last few days. I've been reporting things on a day-by-day basis elsewhere, so there's a documented record, and this is quite pertinent.

Firstly, there's no reason why bitstream should sound the same as LPCM. The digital audio replay architecture is different, and that means the sound may be different. I'd better explain that, quick.

A digital audio signal has two elements - a data stream and a timing stream. Both of these end up at the DAC to create the analogue audio signal, and both need robustness and fidelity.

These streams are quite distinct, and take different critical paths:
The data stream starts at the disc, and ends up at the DAC.
The timing stream starts at the master clock, and also ends up at the DAC.

The bitstream decoding process only affects the data stream, and I think we are all pretty confident that that is lossless, so the DAC is receiving the right data, whichever decoding architecture is used.

However, this architecture MAY affect the path of the timing stream . This isn't necessarily the case, but my experience with the Onkyo suggests that it is. With LPCM, the clock is in the transport, and the path takes the HDMI connection to the receiver and too the DACs. This is a tortuous path, and is full of degradation - like toslink but worse. With bitstream, there's no clock associated with the data because its compressed, and the clock is regenerated in the amplifier, just as it is with DD and DTS. This places the clock right next to the DAC, with robust and direct connection, which is ideal. This doesn't eliminate interference, noise and jitter, but its a very big help.

So with bitstream there is an opportunity to minimise jitter, though this is only achieved if the amplifier doesn't generate its audio clock from the players video clock, in the same way it does with LPCM. For ayear, I've never known which it was, but I think that question has now been answered in my mind, now. Of course, my observations may not apply to other amplifiers, like Pioneers, which have different architectures. I'm itching to find out....

Nick

I'd love to do a double blind jitter test with you. I haven't met a person who claims to hear jitter during multichannel movie soundtracks. With the dynamics involved, it's almost pointless (perhaps a different story for high resolution stereo music).