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Discussion Starter #1
Please help me settle a minor dispute.

A source device which shall go nameless (it's not hi-fi gear, it's a mass produced retail item that sells for about $300) and we'll say hypothetically say it's capable of either bitstream or PCM via its HDMI output to your middle/hi-end hi-fi receiver (which is designed for hi-fi acoustics and retailed for around $2000.)

Which is best for optimal sound (using HDMI output on source to HDMI in on the receiver)

1/ Set the source to bitstream to the receiver and let the receiver's DACs decode any audio codec it encounters.

2/ Set the source to PCM and let the source device (not hi-fi) conduct the decoding and the receiver can handle the raw PCM and just play it back to the speakers.

3/ Set the source's output however you want bitstream/PCM doesn't matter because decoding an audio codec is just like opening a ZIP file anyway, it's all the same. No perceptible acoustic differences will be present.

Let me know which (if either) of the choices you would agree to and why.

Thank you for your input.
Wayde
 

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With bitstream it is possible that there will end up being a bit less clock jitter to the Digital to Audio Converters (DACs) in the receiver. This would be due to the packetizing of the audio data with bitstream thereby requiring a independent clock generated in the receiver. Linear PCM via HDMI will use a clock derived from the HDMI video clock for the DACs. Some report that more jitter to the DACs' clock results.

A high end AVR or Pre-Pro may have much more sophisticated DAC clock recovery circuitry for a PCM input (either via HDMI or S/PDIF). Then the difference (hearing DAC clock jitter effects) may be very hard to detect.
 

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Depends on what the source material is. If its HD Master Adio or other HD coec on a BluRay only having the unamed source component decode it and output PCM will get you ther HD Audio
 

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Discussion Starter #4
Depends on what the source material is. If its HD Master Adio or other HD coec on a BluRay only having the unamed source component decode it and output PCM will get you ther HD Audio
I'm not sure that's right.

I have a BD player and it bitstreams to my AVR (hdmi 1.3) and the receiver decodes DTS HD-MA just fine. If I understand you correctly you're saying that only the source can decode that particular codec.
 

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With bitstream it is possible that there will end up being a bit less clock jitter to the Digital to Audio Converters (DACs) in the receiver.
So, if it was your a/v gear you'd bitstream to the receiver?

from what I understand the differences between cheap DACs and expensive brand name DACs (wolfson, Burr-Brown) are large. I never knew about it being the clock but what I understand is that the digital to analog conversion can be performed in a number of ways... some are done cheaply and generically so as not to require much processing power. Others are done in a more sophistocated manner requiring higher powered DACs that consequently cost more.

Or am I buying into audiophile myths?

I would have to believe that a mid-line Denon DVD player will decode Dolby Digital in a far superior maner than a $50 Wal-Mart special (assuming both had analog outs and could perform the decoding internally).
 

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If I had a new HDMI 1.3 AVR with the new codecs and a new display that uses HDMI 1.3 -- then I would use bitstream output on HDMI 1.3 from my HD-XA2 player.

Yes, the quality of the DAC can matter. But it seems that many hi def players are using good quality (mid-range for audiophiles) DACs anyway so that is not a big factor for mid-range audio users. Those who spend more than $10K for a player or Pre-Pro will feel different. But both linear PCM and bitstream use the DACs at the end destination (AVR, receiver, Pre-Pro). The player's DACs only matter if you are using an analog connection (stereo or multi-channel analog).

Just that DACs need to be accurately clocked (triggered to do a sample conversion) at a consistant time interval, centered where the digital sample data has stabilized at the DAC's inputs. It is possible to hear the effects of inconsistant clocking or a clock that is so skewed off in time that the input sample data is not settled but rather is changing to or from another sample set. This is one real electrical engineering technical detail/requirement that I know can be a factor with the sound quality.

Early CD players outputing linear PCM on a digital S/PDIF (coax or Toslink) connection to the earliest S/PDIF capable receivers had DAC clock jitter issues at the receiver end. Higher end Pre-Pro's reduced this issue with more elaborate PLL clock recovery circuitry.

Sending audio digitized into packets (as bitstream does) for transport via HDMI or IEEE-1394 firewire (iLink) ends up requiring receiver clock circuitry that avoids the "jitter" issue.
 

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I'm not sure that's right.

I have a BD player and it bitstreams to my AVR (hdmi 1.3) and the receiver decodes DTS HD-MA just fine. If I understand you correctly you're saying that only the source can decode that particular codec.
A source device which shall go nameless (it's not hi-fi gear, it's a mass produced retail item that sells for about $300)
Only source device I know that fits that discription (in terms of HD Audio) is a PS3. A PS3 will not bitsteam anything other than Dolby Digital. No high def.

I assumed it was a PS3 as I'm not sure why he wouldn't simply give the nodel number of a BR player?
 

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Only source device I know that fits that discription (in terms of HD Audio) is a PS3. A PS3 will not bitsteam anything other than Dolby Digital. No high def.

I assumed it was a PS3 as I'm not sure why he wouldn't simply give the nodel number of a BR player?
Good call Toolatecrew!

You assumed correct, I didn't want to say PS3 because it enters into the realm of fanboyism and I don't care of it's a PS3 or box of Pop Tarts, I just wanted to know which would be 'optimal'.

Since the PS3 is incapable of bitstreaming the hi-res codecs my contention is that a BD player capable of bitstreaming would be a better option for overall sound quality if you're using a higher-mid range AVR that is capable of decoding the bitstream.

No, that's not a knock on the PS3. I'm sure it's a wonderful device that makes a lot of people very happy. :)

A lot of people get very touchy about it and I wanted to separate facts from favoritism.

If the PS3 were bitstream capable and you had an AVR capable of decoding the hi-res codecs... which would you do - Bitstream or PCM?

I doubt anyone that had a choice would do the latter even if the differences were negligible.

As bob points out cheap DACs have come a long way in recent years. So, maybe it wouldn't matter to anything under a true audiophile grade setup.
 

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Good call Toolatecrew!

You assumed correct, I didn't want to say PS3 because it enters into the realm of fanboyism and I don't care of it's a PS3 or box of Pop Tarts, I just wanted to know which would be 'optimal'.

Since the PS3 is incapable of bitstreaming the hi-res codecs my contention is that a BD player capable of bitstreaming would be a better option for overall sound quality if you're using a higher-mid range AVR that is capable of decoding the bitstream.

No, that's not a knock on the PS3. I'm sure it's a wonderful device that makes a lot of people very happy. :)

A lot of people get very touchy about it and I wanted to separate facts from favoritism.

If the PS3 were bitstream capable and you had an AVR capable of decoding the hi-res codecs... which would you do - Bitstream or PCM?

I doubt anyone that had a choice would do the latter even if the differences were negligible.

As bob points out cheap DACs have come a long way in recent years. So, maybe it wouldn't matter to anything under a true audiophile grade setup.
If the PS3 could bitstream I might well let it do so just so I see the little Dolby HD thingy light up on my 3808. It looks cooler than PCM Multi Channel and I can tell if its DTS HD or Dolby HD or whatever without pushing the the button on the PS3 remote. I'm happy to let whatever piece of gear that is software upgradable to accommodate new formats do the decode.

I do not believe there is any difference in where the HD audio is uncompressed. I subscribe to the zip file analogy.

We are not talking about analog outs here. Its HDMI vs Toslink or HDMI vs HDMI (in terms of a PS3). You can ONLY get HD over HDMI.

I'm no fanboy. I have a PS3 and an HD DVD player. I could have spent more $ and gotten an HDDVD player that would bitstream but saw absolutely no reason to. Its just my opinion though. I can't hear a difference and to me that's all that matters. If someone else can hear a difference more power to them .
 

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Discussion Starter #10
I'm with bob... probably 99.9% of people's gear won't hear a diff. But if it's available, I'd rather bitstream.
 

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Just to clarify, remember:

The player's DACs only matter if you are using an analog connection (stereo or multi-channel analog).
 

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I don't know why DACs would be an issue either. It's a digital source either way passed over a digital cable. It would be the decoder that would come into play. Decode at source or decode at destination is the question.

I personally can't tell the difference when flipping between bitstream and LPCM for Dolby Digital or DTS on my PS3 to my Denon 4306. The only benefit I can tell is that the display on the 4306 reads Dolby Digital rather than Multi Ch In.

One area I could see that it would have effect would be if the decoder (source or destination) extrapolates a higher sample rate from lower one (ie: Denon's AL24 processing or the PS3's audio upconversion). In that being if the source could upsample to 192khz and do nice job of it and the destination can't, then bitstream looses out.
 

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This is basically how I see it (feel free to correct me people), LPCM has the player decoding the soundtrack from its compressed format on the disc into an uncompressed one that is then sent to a compliant receiver. The receiver then plays the data. Bitstream means the compressed audio on the disc is sent untouched from the disc (via the player) to the receiver, the receiver then uncompressed/decodes the sound and plays it.

Which is the best way?

I'd say this depends entirely on each persons setup. Lets assume a receiver that can decode both formats and a player that can send both formats at all levels of sound (upto true HD etc). If you have a basic receiver then you should let your player decode as it will be a superior decoder (LPCM). If you have very good HT then you should let the AV receiver do the decoding (bitstream) as this will be superior to the players.

As someone has already stated, the PS3 is different as it wont send HD sound as bitstream so for that particular device LPCM is what you need. All stand alone player will send both formats just fine as far as i know.
 

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If you have a basic receiver then you should let your player decode as it will be a superior decoder (LPCM)...
But is not just any basic receiver, Right??? ... you CAN NOT GET TrueHD or DTS HD through optical or coaxial cable, you need to use the analog multi channel input, Right???
 

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Yes...exactly...most "Basic" receivers don't have the lossless codec decoders. Unless you consider something like the Onkyo 606 or a Pioneer VSX-1018AH "basic". I would think that the digital bits outputted would be the same no matter what decoded it. They all use the same algorithm after all.
 

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... Onkyo 606 or a Pioneer VSX-1018AH "basic". I would think that the digital bits outputted would be the same no matter what decoded it. They all use the same algorithm after all.
Those AVR are able to decode TrueHD and DTS HD ...

How do you connect/use an AVR that can't decode them but your DVD player can??? ... It can't be done through the optical/coaxial cable, Right???
 

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You need to either use the HDMI connection and the then receiver must support LPCM over HDMI

or

the player must have 5.1/7.1 analog outputs and the receiver must have 5.1/7.1 analog inputs

You are correct that the lossless audio cannot be passed over optical or coaxial in either encoded or decoded form.
 

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You need to either use the HDMI connection and the then receiver must support LPCM over HDMI

or

the player must have 5.1/7.1 analog outputs and the receiver must have 5.1/7.1 analog inputs

You are correct that the lossless audio cannot be passed over optical or coaxial in either encoded or decoded form.
That's what I thought ... :sad:

I was getting excited ... my RXV 2700 can't decode TrueHD or DTS HD, it has the multichannel inputs but my HD D3 doesn't have the multichannel outputs so I'm using optical/coaxial :doh:
 

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Hi David, dont get too worked up about TrueHD or DTS HD as there is very little noticeable difference between DTS and Dolby digital+ over TrueHD or DTS HD the bitrate numbers may look allot higher but to most people it really is not a huge noticeable difference.
 

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Hi David, dont get too worked up about TrueHD or DTS HD as there is very little noticeable difference between DTS and Dolby digital+ over TrueHD or DTS HD the bitrate numbers may look allot higher but to most people it really is not a huge noticeable difference.
Thank you ... :T

Sometimes I think that HT beginners have more fun (is not that I'm an expert but I learned a lot here :bigsmile:) because they don't know or care about getting the best out of their system :yes: ... until they start learning and start reading ... then they become like me :dizzy: :yes:
 
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