24/96 releases sometimes just upscaled 16/44? Options

[jamie_P84]

I know many people have developed a special attachment to the CD format - its 16-bits, 44.1kHz sample rate, and its simple interpolation of missing samples to "hide" its read errors represent an almost God-like perfection. This not only brings a great deal of comfort and reassurance to its devotees, but gives the format a unique property or 'essence' which means it can never be bettered.

As one of the deluded and unenlightened heathens who finds himself unsatisfied with CD, I can only beg my superiors to show mercy in shielding me from biased moderation, and from attacks upon my audio equipment, my hearing, my sanity and my brain's ability to adequately perceive not only sound, but the rest of the universe around me.

With that in mind, I have the following quick question:
For test purposes I have acquired a small number of 24-bit 96kHz lossless audio files derived from DVD-A and SACD releases. However, a spectrum analysis of their content always shows a sharp roll-off at either 22050Hz or 24000Hz, suggesting that these releases are nothing more than upscaled versions of previous 16-bit 44.1 or 48kHz releases (complete with the so-called 'loudness war' compression in most cases).

So, is it normal for these high resolution releases to be upscaled?
Which DVD-Audio/SACD releases are known to be genuine 24/96?

Thanks,
jamie.

This post has been edited by db1989: Jun 5 2012, 00:54

Reason for edit: Stop it. Reference: http://hydrogenaudio.org/forums/?showtopic=95366

[krabapple]

Here's one. From Neil Young's "Harvest ' DVDA, which has nominal 192kHz sample rate (Neil Young is utterly ridiculous when it comes to audio) , 24bits

No real musical content above 20 Hz or so, but the visible 'cutoff' for background noise -- the faint purple/blue speckling going completely to black -- is slightly above 40kHz, suggesting that perhaps the 'effective' SR was 88.2.



This post has been edited by krabapple: Jun 3 2012, 18:01

[uart]

Here's one. From Neil Young's "Harvest ' DVDA, which has nominal 192kHz sample rate (Neil Young is utterly ridiculous when it comes to audio) , 24bits

No real musical content above 20 Hz or so, but the visible 'cutoff' for background noise -- the faint purple/blue speckling going completely to black -- is slightly above 40kHz, suggesting that perhaps the 'effective' SR was 88.2.

Thanks for posting that. Not having any HD content myself, I was interested to see a spectrograph.

Given that "Harvest" is rather old, what would that have been mastered from krabapple, the original tapes?

BTW. You can just make out a faint line in that spectrum at about 30 kHz, I wonder what that is?

[jamie_P84]

Thanks for posting that. Not having any HD content myself, I was interested to see a spectrograph.
Given that "Harvest" is rather old, what would that have been mastered from krabapple, the original tapes?

Thanks from me also - I might purchase a copy of "Harvest".
Original analogue master tapes will certainly contain content above 24kHz, and a level of depth beyond that of 16-bits.

[krabapple]

Original analogue master tapes will certainly contain content above 24kHz, and a level of depth beyond that of 16-bits.

Why do you believe that?

[bandpass]

Original analogue master tapes will certainly contain content above 24kHz, and a level of depth beyond that of 16-bits.

ATR Master Tape Specifications: http://www.atrtape.com/technical.php

Frequency Pass Band 20Hz-20Khz
Peak Dynamic Range 86 dB

[jamie_P84]

ATR Master Tape Specifications: http://www.atrtape.com/technical.php

Frequency Pass Band 20Hz-20Khz
Peak Dynamic Range 86 dB

Probably means a flat frequency response and linearity from 20Hz-20Khz within pre-defined tolerances. Unlike digital recorders, analogue ones do not require a sharp cut-off in frequency response above their rated maximum.
I have many AAD CDs which show no signs of roll-off at 20kHz, incidentally.
Dynamic range of analogue vs digital cannot be compared so easily either - the former can provide subjectively useable dynamic range which exceeds that of its digital equivalent, because it 'fails gracefully' above its rated maximum range, continuing to capture information which, in the digital domain, would have simply been truncated (resulting in a clipped waveform).

PS. It would be rather unfortunate if this thread were to turn into "yet another analogue vs digital debate", all because my original post insulted certain people's "religion".

[krabapple]

Probably means a flat frequency response and linearity from 20Hz-20Khz within pre-defined tolerances. Unlike digital recorders, analogue ones do not require a sharp cut-off in frequency response above their rated maximum.

True, they don't but that doesn't mean they are 'flat' or distortion-free in that range. That is the point, I would think. LPs have a FR that extends beyond 20kHz, but what's there, at what level, and how distortion-free is it?

I have many AAD CDs which show no signs of roll-off at 20kHz, incidentally.

So, how have you determined that these CDs you refer to have 'no signs of rolloff' at the redbook limit?

Dynamic range of analogue vs digital cannot be compared so easily either - the former can provide subjectively useable dynamic range which exceeds that of its digital equivalent, because it 'fails gracefully' above its rated maximum range, continuing to capture information which, in the digital domain, would have simply been truncated (resulting in a clipped waveform).

'fails gracefully? "subjectively usable dynamic range'? capturing extra 'information'?

Ok let's run with all that. What is the 'subjectively usable' range that analog tape offers, how many people listen to the original analog tape, and what is the subjectively usable DR that dithered, noise-shaped Redbook offers as a delivery format, and what is the subjectively usable DR that LP or reel-to-reel consumer formats offer? What is the background noise level of a typical listening room?

PS. It would be rather unfortunate if this thread were to turn into "yet another analogue vs digital debate", all because my original post insulted certain people's "religion".

PS I took you not to be a troll, but now I wonder.

This post has been edited by krabapple: Jun 4 2012, 06:58

[jamie_P84]

LPs have a FR that extends beyond 20kHz, but what's there, at what level, and how distortion-free is it?

Depends, as always, upon the condition of the record and the quality of the recording/playback equipment.
As an example though, at least one commercial quadraphonic LP system (Quadradisc) used a pair of modulated carriers for the extra channels' content, cut to the vinyl in the range of 18-45kHz. High end record players can reproduce even higher frequency signals.

I have many AAD CDs which show no signs of roll-off at 20kHz, incidentally.

So, how have you determined that these CDs you refer to have 'no signs of rolloff' at the redbook limit?

I use an old WinAmp plugin called "DSP Spectrum Tool" (it crashes on newer WinAmp versions) to reliably check for roll off.
CD content derived from an oversampling ADC often has no roll off at 20kHz - frequency response can remain flat up to 22.05kHz.

'fails gracefully? "subjectively usable dynamic range'? capturing extra 'information'?

Welcome to analogue recording - things aren't so clean-cut as with digital are they.

PS. It would be rather unfortunate if this thread were to turn into "yet another analogue vs digital debate", all because my original post insulted certain people's "religion".

PS I took you not to be a troll, but now I wonder.

My original post was about sourcing genuine native 24/96 recordings to try out on my new soundcard - nothing more.
I anticipated the instinctive rush to defend the holy redbook, which is why I begged my superiors to show me mercy. What more did you want?

Anyway, here is an example spectrum plot of a 24/96 DVD-A release with sharp roll-off just below 22.05kHz (the display range is 0 - 48kHz and -130dB - 0dB):

[krabapple]

LPs have a FR that extends beyond 20kHz, but what's there, at what level, and how distortion-free is it?

Depends, as always, upon the condition of the record and the quality of the recording/playback equipment.
As an example though, at least one commercial quadraphonic LP system (Quadradisc) used a pair of modulated carriers for the extra channels' content, cut to the vinyl in the range of 18-45kHz. High end record players can reproduce even higher frequency signals.

Hmmm, you quote and answer one question of mine out of several.

For a quad carrier signal -- that's the one case where it really is demonstrably important to get that ultrahigh frequency signal onto vinyl intact, and to preserve it. Not so you can *hear* that frequency, mind you. And btw analog quad is a dead technology, have you noticed?

So, for a typical analog product (stereo LP not being quite so dead as quad LP), what is the demonstrable importance of having >=20kHz signals pressed to vinyl undistorted and at full level? And how commonly is that achieved?

I have many AAD CDs which show no signs of roll-off at 20kHz, incidentally.

So, how have you determined that these CDs you refer to have 'no signs of rolloff' at the redbook limit?

I use an old WinAmp plugin called "DSP Spectrum Tool" (it crashes on newer WinAmp versions) to reliably check for roll off.
CD content derived from an oversampling ADC often has no roll off at 20kHz - frequency response can remain flat up to 22.05kHz.

No one disputes that Redbook-rate ADC can yield an flat FR across practically all its bandwidth, with respect to the input signal, maybe fading a little at the very top. My question meant, how do you know there wasn't any rolloff earlier in the recording chain, if the input is coming from, say, an old analog tape? What 'signs' would you look for?

My original post was about sourcing genuine native 24/96 recordings to try out on my new soundcard - nothing more.
I anticipated the instinctive rush to defend the holy redbook, which is why I begged my superiors to show me mercy. What more did you want?

I pretty much know what to expect from you now, I think.

Anyway, here is an example spectrum plot of a 24/96 DVD-A release with sharp roll-off just below 22.05kHz (the display range is 0 - 48kHz and -130dB - 0dB):

Yes, some 'high rez' releases don't really exploit the touted advantages of 'high rez' (and did you know, many CDs don't exploit the 16bits of dynamic range available to them?). Yes, some 'high rez' release are just upconversions of previously lowpassed signals. And actually, even if they were bona fide 96kHz/24bit recordings from start to finish, it might be very difficult tell them apart from a Redbook downconversion in a fair listening test, and even then the difference, if heard, might be due to hardware, rather than the audio format. Implying that as a consumer audio delivery format, 'high rez' might be more a marketing ploy than anything else.


Last but not least, if you do plan to 'use your ears' to determine if a true 24/96 recording differs audibly from the same recording at 16/44, does that mean you'll do the test blind, or is that sort of thing too religious for a rebel like you?

This post has been edited by krabapple: Jun 5 2012, 04:14

[jamie_P84]

Depends, as always, upon the condition of the record and the quality of the recording/playback equipment.
As an example though, at least one commercial quadraphonic LP system (Quadradisc) used a pair of modulated carriers for the extra channels' content, cut to the vinyl in the range of 18-45kHz. High end record players can reproduce even higher frequency signals.

Hmmm, you quote and answer one question of mine out of several.

So, if people come here expressing a personal desire to exceed the limits of glorious redbook, they'd better have the answers to an array of unduly-demanding questions plucked out of thin air, pertaining to legacy analogue technologies which they haven't necessarily even advocated, about specific noise levels and all the rest.
Obviously the individuals making them up -ahem- reeling them off won't take a poster seriously otherwise, which is handy.

For a quad carrier signal -- that's the one case where it really is demonstrably important to get that ultrahigh frequency signal onto vinyl intact, and to preserve it. Not so you can *hear* that frequency, mind you. And btw analog quad is a dead technology, have you noticed?

So, for a typical analog product (stereo LP not being quite so dead as quad LP), what is the demonstrable importance of having >=20kHz signals pressed to vinyl undistorted and at full level? And how commonly is that achieved?

More analogue-bashing and more unduly-demanding questions. Some people do have a special attachment to analogue - in much the same way as some have a special attachment to CD. Both could be described as "religious" attachments, and indeed the plethora of analogue vs digital debates on the 'net often resemble religious wars.
Btw I never expressed any particular affection for analogue, did you notice?

I'll respond to the issue of frequency response beyond the redbook maximum, since some posters keep hammering on it (bit depth having been mentioned far less, interestingly): I'm under no illusions as to the frequency range of human hearing. I myself could hear nothing beyond 26kHz in a test last year.
Some have speculated that content above this range can still influence the way we perceive sounds, and others suggest that the presence of a brickwall filter at a given frequency (22.05kHz for example) - which doesn't exist in real-world sounds - may itself create audible artefacts across the rest of the audible spectrum.
No doubt you'll all disagree strongly with both of these anti-redbook views.

Either way, sharp roll off at redbook maximum remains a largely reliable means of identifying upscaled content published on high resolution formats, and you can't get away from that.

Yes, some 'high rez' releases don't really exploit the touted advantages of 'high rez' (and did you know, many CDs don't exploit the 16bits of dynamic range available to them?). Yes, some 'high rez' release are just upconversions of previously lowpassed signals. And actually, even if they were bona fide 96kHz/24bit recordings from start to finish, it might be very difficult tell them apart from a Redbook downconversion in a fair listening test, and even then the difference, if heard, might be due to hardware, rather than the audio format. Implying that as a consumer audio delivery format, 'high rez' might be more a marketing ploy than anything else.

Last but not least, if you do plan to 'use your ears' to determine if a true 24/96 recording differs audibly from the same recording at 16/44, does that mean you'll do the test blind, or is that sort of thing too religious for a rebel like you?

I assume your use of the phrase 'high rez' in the place of 'high resolution' is an attempt to cheapen its image? I'd be more impressed if you provided a more scientific analysis. In a professional environment, the behaviour I've seen in this thread just wouldn't cut it.

I've nothing against blind listening tests, but I don't think they're the holy grail, especially when conducted in the non-controlled conditions of individuals' homes. And of course, people at home can fabricate the results to suit their own agendas.

Interesting that you should mention the use of a fair listening test to compare bona fide 24/96 with redbook. That's precisely the sort comparison I'm seeking to make (see post #1).

This post has been edited by jamie_P84: Jun 5 2012, 15:05

[Arnold B. Kruege...]

So, if people come here expressing a personal desire to exceed the limits of glorious redbook, they'd better have the answers to an array of unduly-demanding questions plucked out of thin air, pertaining to legacy analogue technologies which they haven't necessarily even advocated, about specific noise levels and all the rest.

BTW is the pity party over yet? ;-)

The questions that Krab asked weren't plucked out of thin air, and are not unduly-demanding of people who know the relevant facts that every vinyl advocate should know.

Some of us are the people who lived through the days when vinyl was all we had, and who watched CD-4 fall on its face. Some of us have gotten vinyl cutting chips in our hair and pants cuffs.

So far your posts have brought nothing new to the table.

Are we lying in wait and trying to trick you, or have we just been here and done that a zillion times before, going back years if not decades?

You made some stock claims, and Krab kinda gently popped some critical questions that many of us including him already know the proper, scientific answers to.

You know the one about good lawyers never asking questions that they don't already know the answers to?

;-)

The bottom line is that most vinyl advocates don't know the relevant facts.

And as far as the hi-rez thing goes, let me recommend HDTracks.com. If I want to know the titles of tracks with true hi-rez contents for sure, I buy them one at a time and test them..

I did post here a list of about 20 tracks, and my prognostications about whether or not they had a hi rez heritage not too long ago.

A little quickie searching of Wikipedia and Amazon comes up with the following release dates:

Patricia Barber – Nightclub (Mobile Fidelity UDSACD 2004) Original Release Date: September 26, 2000

Chesky: Various -- An Introduction to SACD (SACD204) needs track by track analysis

Chesky: Various -- Super Audio Collection & Professional Test Disc (CHDVD 171) needs track by track analysis

Stephen Hartke: Tituli/Cathedral in the Thrashing Rain; Hilliard Ensemble/Crockett
(ECM New Series 1861, cat. no. 476 1155, SACD) Audio CD (November 18, 2008)

Bach Concertos: Perahia et al; Sony SACD Audio CD (March 12, 2002)

Mozart Piano Concertos: Perahia, Sony SACD Audio CD (October 25, 1990)

Kimber Kable: Purity, an Inspirational Collection SACD T Minus 5 Vocal Band, no cat. no audio CD equivalent found

Tony Overwater: Op SACD (Turtle Records TRSA 0008) Audio CD (March 18, 2008)

McCoy Tyner Illuminati SACD (Telarc 63599) Audio CD (June 22, 2004)

Pink Floyd, Dark Side of the Moon SACD (Capitol/EMI 82136) Audio CD (March 1973)

Steely Dan, Gaucho, Geffen SACD Audio CD (1980)


Alan Parsons, I, Robot DVD-A (Chesky CHDD 2003) Audio CD (1977)


BSO, Saint-Saens, Organ Symphony SACD (RCA 82876-61387-2 RE1) Audio CD (July 5, 1991)


Carlos Heredia, Gypsy Flamenco SACD (Chesky SACD266) Audio CD (February 15, 1996)


Shakespeare in Song, Phoenix Bach Choir, Bruffy, SACD (Chandos CHSA 5031) Audio CD (September 21, 2004)

Livingston Taylor, Ink SACD (Chesky SACD253) Audio CD (September 23, 1997)

The Persuasions, The Persuasions Sing the Beatles, SACD (Chesky SACD244) Audio CD (February 26, 2002)

Steely Dan, Two Against Nature, DVD-A (24,96) Giant Records 9 24719-9 Audio CD (May 2, 2006)

McCoy Tyner with Stanley Clark and Al Foster, Telarc SACD 3488 Audio CD (January 25, 2000)

I would suggest that anything released prior to 1997 would have been originally tracked, mixed and/or mastered in what we would call now a legacy format, either 15 ips analog tape or 44-48-50 KHz sampled digital. Anything originally released after 2001 is more or less likely to have some HD DNA.

Hope this helps!