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post #751 of 761 Old 02-22-2014, 03:32 PM
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Quote:
Originally Posted by krabapple View Post

HDCD, at least as originally implemented in hardware (I can't really say for sure what Microsoft's software version now does) had three components that conceivably could affect the sound

-- use of Keith Johnson's (then) high-quality ADC and DAC
-- use of switchable filters
-- optional use of 'peak extension' , whereby the file, if played back on a device with an HDCD decoder, would undergo dynamic range expansion.
Decent summary. Here is what Arny post about HDCD and SACD on usenet newsgroup:

Arny Krüger wrote:

> "Tushar" wrote in message
> news:803qsp$2uj$1@nnrp1.deja.com...
> > Could someone explain in laymans terms how the dsd technology used
> in
> > the SACD format is different from the PCM used in the CD and if it
> is
> > superior what are the reasons.
>
> I would like to do that, but the technical literature that I've
> been able to pull together from various sources so far lacks the
> detail I feel I need to reliably do so.
>
> Reading between the lines and speculating wildly, SACD seems to me
> to be a bit stream-oriented digital data coding technique, one that
> effectively uses data words of various lengths for different parts
> of the audio spectrum and/or sound levels. There seem to be claims
> that such data that is transmitted is not subject to lossy
> compression, but if, as I may erroneously or correctly infer,
> different parts of the frequency and/or amplitude domains are coded
> with different length data words, then it SACD is in fact a form of
> perceptual (lossy) coding. FWIW, HDCD seems to have implemented a
> subset of these benefits.


[bolding mine] He says SACD is a lossy format and HDCD is a subset of SACD! eek.gif I guess he is going by the similarity of the last two letters in each technology with that last remark???

As I think most people know, he is not remotely in the same planet with respect to what these technologies are. This is the story throughout this thread. And we are having another episode of it with "masking."

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post #752 of 761 Old 02-22-2014, 03:42 PM
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Quote:
Originally Posted by Frank Derks View Post

This was explained at an AES meeting a couple of years ago.

http://www.tvtechnology.com/opinions/0087/digital-audio-sample-rates-the--khz-question-/184354
Thanks much for the great article! smile.gif

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post #753 of 761 Old 02-23-2014, 05:40 AM
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I have a couple of SACDs that I got primarily because they were going out of print (Rolling Stones Beggars Banquet and Let It Bleed). Also have Sticky Fingers. To be honest, these are not that much better than the same thing on a CD. They have a little bit higher dynamic range, but the sound is not a huge improvement unless you're running them out to a DSD DAC. My Sony BDP-S470 plays the SACD layer too.

Just go after a good CD mastering and it's good enough.
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post #754 of 761 Old 02-23-2014, 06:44 AM
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Quote:
Originally Posted by amirm View Post

Quote:
Originally Posted by krabapple View Post

HDCD, at least as originally implemented in hardware (I can't really say for sure what Microsoft's software version now does) had three components that conceivably could affect the sound

-- use of Keith Johnson's (then) high-quality ADC and DAC
-- use of switchable filters
-- optional use of 'peak extension' , whereby the file, if played back on a device with an HDCD decoder, would undergo dynamic range expansion.
Decent summary. Here is what Arny post about HDCD and SACD on usenet newsgroup:

Arny Krüger wrote:

> Reading between the lines and speculating wildly, SACD seems to me
> to be a bit stream-oriented digital data coding technique, one that
> effectively uses data words of various lengths for different parts
> of the audio spectrum and/or sound levels. There seem to be claims
> that such data that is transmitted is not subject to lossy
> compression, but if, as I may erroneously or correctly infer,
> different parts of the frequency and/or amplitude domains are coded
> with different length data words, then it SACD is in fact a form of
> perceptual (lossy) coding. FWIW, HDCD seems to have implemented a
> subset of these benefits.


[bolding mine] He says SACD is a lossy format and HDCD is a subset of SACD! eek.gif I guess he is going by the similarity of the last two letters in each technology with that last remark???

As I think most people know, he is not remotely in the same planet with respect to what these technologies are. This is the story throughout this thread. And we are having another episode of it with "masking."

Yup, apparently I again unfortunately managed to talk right over some people's heads. Please note - Amir has tried this exact same stunt once before - its in the AVS archives. I tried to explain it then, but here we go again - Amir apparently can't even come up something new to work his magic on - he's been dredging the archives and just repeated the same mistake he made before! Here's the link: http://www.avsforum.com/t/1425262/are-audio-companies-all-involved-in-a-huge-conspiracy/210#post_22361426

In order to understand what I wrote above many years ago one needs to understand two facts:

(1) Ever wonder what happens when perceptually-based data coding (MP3, AAC, etc.) does to the signals that are removed during coding? The short answer is that they are replaced by noise. People don't hear this noise in a high quality MP3 because the noise is hidden away in places where the human perceptual process does not go. One reason why really low bitrate MP3s sound so bad is that push has come to shove and this noise is so widespread and becomes audible.

(2) DSD - the coding technique used by SACD in its way does a simplified version of the same thing:



The blue line is the noise floor of a DSD recording. One way to look at it is to say that above about 15 KHz really small signals are replaced by noise. This replacement process becomes more and more pronounced as the frequency increases. People don't hear this noise in a SACD because the noise is hidden away in places where the human perceptual process does not go.

That my friends is the similarity between MP3s and SACD that I was talking about long long ago.
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post #755 of 761 Old 02-23-2014, 06:57 AM
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Quote:
Originally Posted by arnyk View Post

That my friends is the similarity between MP3s and SACD that I was talking about long long ago.
I won't bother to critique your explanation Arny because it is so wrong that hopefully no one is agreeing with you. Clearly you did not know what SACD or HDCD remotely were about but that didn't stop you from saying otherwise. What is even more surprising is that you are sticking to it now! You really thought that we went from uncompressed format in CD to "super audio" (CD) and there we applied lossy/perceptual compression? How would that have been sold to anyone as a step above CD?

In all these years, I have never, ever seen anyone say SACD is a lossy system. Or that HDCD is a subset of it. Compare your explanation to that of Krab. You see any resemblance? I don't think anyone does.

And what the heck "different length data words" have to do with anything you just said? Star Trek language meant to impress the layman?

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post #756 of 761 Old 02-23-2014, 10:27 AM
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Quote:
Originally Posted by hogger129 View Post

I have a couple of SACDs that I got primarily because they were going out of print (Rolling Stones Beggars Banquet and Let It Bleed). Also have Sticky Fingers. To be honest, these are not that much better than the same thing on a CD. They have a little bit higher dynamic range, but the sound is not a huge improvement unless you're running them out to a DSD DAC. My Sony BDP-S470 plays the SACD layer too.

Just go after a good CD mastering and it's good enough.

FWI, I once analyzed a track of those Stones SACDs -- I compared the digitally captured (at 88kHz/24 bits) analog output of the DSD layer, versus a rip of the CD layer -- and when level-matched, their 'dynamic range' and frequency plots (within the audible range) were virtually identical. I as unable to tell them apart by ABX either. This suggests to me that the CD layer is really just a downconversion of the SACD layer, which I think is the proper way to do it.

There are, of course, hi-rez hybrid releases that 'cheat' -- the 'hi rez' layer receives a significantly different mastering from the CD layer. Typically in those cases, the CD layer has a reduced dynamic range compared to the hi rez layer. Unwary listeners may conclude that hi rez sounds 'better than CD' when it's not really the formats that are causing the difference.
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post #757 of 761 Old 02-23-2014, 11:22 AM
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Quote:
Originally Posted by arnyk View Post

Yup, apparently I again unfortunately managed to talk right over some people's heads. Please note - Amir has tried this exact same stunt once before - its in the AVS archives. I tried to explain it then, but here we go again - Amir apparently can't even come up something new to work his magic on - he's been dredging the archives and just repeated the same mistake he made before! Here's the link: http://www.avsforum.com/t/1425262/are-audio-companies-all-involved-in-a-huge-conspiracy/210#post_22361426

In order to understand what I wrote above many years ago one needs to understand two facts:

(1) Ever wonder what happens when perceptually-based data coding (MP3, AAC, etc.) does to the signals that are removed during coding? The short answer is that they are replaced by noise. People don't hear this noise in a high quality MP3 because the noise is hidden away in places where the human perceptual process does not go. One reason why really low bitrate MP3s sound so bad is that push has come to shove and this noise is so widespread and becomes audible.

(2) DSD - the coding technique used by SACD in its way does a simplified version of the same thing:



The blue line is the noise floor of a DSD recording. One way to look at it is to say that above about 15 KHz really small signals are replaced by noise. This replacement process becomes more and more pronounced as the frequency increases. People don't hear this noise in a SACD because the noise is hidden away in places where the human perceptual process does not go.

That my friends is the similarity between MP3s and SACD that I was talking about long long ago.

This graph shows the theoretical dynamic range of dsd. The actual noise floor is much, much higher for dsd.

This graph is some of the dsd marketing fluf used to show dsd supposed 'superiority'. It omits the effect of dither and noise shaping on 24bit pcm dynamic range.

A more realistic noise comparison is shown in fig 2:

http://www.stereophile.com/content/dcs-verdi-sacd-transport-purcell-dd-converter-elgar-plus-da-converter-measurements
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post #758 of 761 Old 02-23-2014, 11:38 AM
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Quote:
Originally Posted by Frank Derks View Post

Quote:
Originally Posted by arnyk View Post




The blue line is the noise floor of a DSD recording. One way to look at it is to say that above about 15 KHz really small signals are replaced by noise. This replacement process becomes more and more pronounced as the frequency increases. People don't hear this noise in a SACD because the noise is hidden away in places where the human perceptual process does not go.
.

This graph shows the theoretical dynamic range of dsd. The actual noise floor is much, much higher for dsd.

The actual noise floor of any real world recording is much, much higher.



This is of someones studio control room. Nothing to write home about, but typical. The rooms I work in are at least 10 dB better.
Quote:
This graph is some of the dsd marketing fluf used to show dsd supposed 'superiority'. It omits the effect of dither and noise shaping on 24bit pcm dynamic range.

I'm not sure of that given that it seems to show 24/96 and 24/192 outperforming DSD across most of the frequency ranges measured.
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post #759 of 761 Old 02-23-2014, 11:48 AM
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Must be someone's room in the US. 120 Hz transformer hum stands out like a sore thump.smile.gif
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post #760 of 761 Old 02-23-2014, 01:17 PM
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Originally Posted by Frank Derks View Post

Must be someone's room in the US. 120 Hz transformer hum stands out like a sore thump.smile.gif

IMO no excuse for that!
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post #761 of 761 Old 02-23-2014, 01:43 PM
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Quote:
Originally Posted by arnyk View Post

IMO no excuse for that!
Except that he lives in 50 Hz country (Argentina). http://www.gearslutz.com/board/8608183-post213.html

"Originally Posted by Jens Eklund View Post
60 & 120 Hz and no decay… looks like AC mains background noise to me (assuming where in a 60 Hz AC country naturally).

OP responds with:
Here in Argentina is 220V/50Hz"


This is some guy's home studio and is asking for help to optimize his room. No one could figure out where the 120 Hz is coming from.

Why would you post his measurements here and without any link to the discussion Arny?

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