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24/192 Music Downloads and why they make no sense - Page 2

post #31 of 761
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Originally Posted by Theresa View Post

… Personally I can hear a difference

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Originally Posted by mcnarus View Post

… No, you really can't. No one can.

I agree, you can't hear the difference and am happy to read that others agree as well … if one believes they can hear a difference, they should load up Foobar2K, install ABX Comparator to try a double-blind listening test between two tracks for themselves. The only reason I could see 24-bit/192kHz format is for mastering/mixing the original recordings.

Edit: BTW both are free software
post #32 of 761
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Originally Posted by Ovation View Post

There is also the MCH aspect--I consider that the most important benefit of SACD (and thus my SACD purchases are, with rare exceptions, MCH).

Same for me.
post #33 of 761
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Originally Posted by arnyk View Post

That's because he didn't feel the need to given the number of other papers that mention this effect and even go way out of their way to address is.

I would imagine if you write an article, it is for people who don't already know the answer . In this case, saying there is a listening test that demonstrates intermodulation distortion of this type is audible but not mentioning the author, or anything else for one to go and read more about is not proper way to present data. But maybe that is just me .

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Their name is legion.

Here is one example:

Example? I thought you said you knew the test that demonstrates audibility of ultrasonic induced IMD as Monty says.

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"Most of the conventional audio systems that have been used to present sound for determining sound quality were found to be unsuitable for this particular study. In the conventional systems, sounds containing HFCs are presented as unfiltered source signals through an all-pass circuit and sounds without HFCs are produced by passing the source signals through a low-pass filter Thus the audible low-frequency components (LFCs) are presented through different pathways that may have different transmission characteristics, including frequency response and group delay. In addition, inter-modulation distortion may differentially affect LFCs. Therefore it is difficult to exclude the possibility that any observed differences between the two different sounds, those with and those without HFCs, may result from differences in the audible LFCs rather than from the existence of HFCs. To overcome this problem, we developed a bi-channel sound presentation system that enabled us to present the audible LFCs and the nonaudible HFCs either separately or simultaneously. First, the source signals from the D/A converter high-speed, one-bit coding signal processor were divided in two. Then, LFCs and HFCs were produced by passing these signals through programmable low-pass and high-pass filters respectively, with a crossover frequency of 26 or 22 kHz and a cutoff attenuation of 170 or 80 dB/octave, depending on the type of test. Then, LFCs and HFCs were separately amplified with power amplifiers, respectively, and presented through a speaker system consisting of twin cone-type woofers and a horn-type tweeter for the LFCs and a dome-type super tweeter with a diamond diaphragm for the HFCs. This sound reproduction system had a flat frequency response of over 100 kHz. The level of the presented sound pressure was individually adjusted so that each subject felt comfortable; thus the maximum level was approximately 80–90 dB sound pressure level (SPL) at the listening position."

I know this report. It is famous Hyrpsonics report. I would think if you want to back the claim that 44.1 Khz is enough, this is the last study you want to cite. From its summary on top: http://jn.physiology.org/content/83/6/3548.full

"Although it is generally accepted that humans cannot perceive sounds in the frequency range above 20 kHz, the question of whether the existence of such “inaudible” high-frequency components may affect the acoustic perception of audible sounds remains unanswered. In this study, we used noninvasive physiological measurements of brain responses to provide evidence that sounds containing high-frequency components (HFCs) above the audible range significantly affect the brain activity of listeners."


Back to Monty's article, I was looking for evidence behind this statement:

"Neither audio transducers nor power amplifiers are free of distortion, and distortion tends to increase rapidly at the lowest and highest frequencies. If the same transducer reproduces ultrasonics along with audible content, harmonic distortion will shift some of the ultrasonic content down into the audible range as an uncontrolled spray of intermodulation distortion products covering the entire audible spectrum. Harmonic distortion in a power amplifier will produce the same effect. The effect is very slight, but listening tests have confirmed that both effects can be audible."

Is there a report that validates the last sentence Arny? I am genuinely asking.

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Amir, the paper you object to so strenuously full of factoids that are well known to people who are well read.

I am not objecting to Monty's paper. I am just saying if you want an authoritative view of this topic, there is far better work as in the case of Bob Stuart's paper presented at AES. Monty's designed an audio codec. That gives him some understanding of what we are talking about here. But not as complete a picture as we like. Certainly I would not go to him to hear about distortion products in amplifiers.

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Again Amir if you were well-read you'd know that musical program material with this kind of spectral content is commonly used by advocates of very high sample rates. One word: Gamalon.

Do you believe they are right? If you do, then we better give them what is recorded and not chop it out because you and I think it shouldn't be there, but the talent who heard the music heard it that way -- IMD distortion and all!!!.

If it is not there, then why you are not complaining about Monty's representation as I did? You think it is OK to make a case of ultrasonics not being good based on assuming it has amplitude at 26 Khz the same as your music at 7 Khz?

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It is highly unlikely that there would be a SACD with this kind of spectral content due to noise shaping.

Well if even with SACD and noise shaping you can't get to that level of ultrasonics, seems like you are agreeing with me that Monty's test was not representative. If so, why did you post his graph and praised him by saying "enough said?" Clearly enough wasn't said or he should have noted at least that his simulation/test -- which as yet we don't know where it came from -- is probably not representative of normal content.

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Figure 3 shows that the shaped noise above 20 KHz is 55 dB or more below FS. It is highly unlikely to be the source of audible IM products with even marginal equipment.

So again I ask why you accepted Monty's notion that his graph was representative of the situation at hand.

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Depends on how important it is to you that listeners have the most sonically accurate possible reproduction. In this case chopping off the ultrasonics provides more accurate (as in less audible distortion) sound for a wider audience of listeners.

I don't need someone else to chop them for me. I can do them myself digitally or can have my equipment do it if it is an issue. Better yet, I can compare different approaches. As I noted above, remember, when the music was mixed and approved by the talent, whatever is wrong with ultrasnoics was there.

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Remember, people who produce mainstream music recordings don't make money by selling recordings that go out of their way to make their customer's audio systems sound bad.

That's neither here nor there. I just got the Blu-ray of Adele concert at Albert Hall. The Blu-ray sounds nice. The CD, not so much. Did they go out of their way to make the CD sound bad? I don't know. Maybe they were told it had to be louder, etc. I don't know. What I know is that I like the 48Khz soundtrack better. Wish I could have downloaded that version instead of the CD.

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Irrelevant argument. This discussion is not about recording formats that support frequencies limited to just 26.5 KHz. It is about recording formats like DSD (SACD) that claim response up to 90 KHz and beyond.

I don't know why you throw DSD in there. Most music is not mixed and finalized in DSD but high-resolution PCM. I said that once we have that, and whoever produced it is happy with it, we should deliver that to the consumer. Chopping it down to size was necessary for CD but it is not for digital distribution. That point is 100% relevant because it completely sidesteps these arguments. You can chop down your download to 10 bits, 16 Khz if you wanted, and someone else could keep it as is. Everyone is happy. Heck, if you don't want to download the high-res version, you can get the low res version.

Your argument seems to be let's continue to force people get CD spec audio. Why? Am I harmed anyway and you and Monty are the ones to save me?
post #34 of 761
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Originally Posted by amirm View Post

I know this report. It is famous Hypersonics report. I would think if you want to back the claim that 44.1 Khz is enough, this is the last study you want to cite.

Amir, you fell into one of my traps, again! The fact that you could recognize this report from a tiny quote of it shows something about your comments here on AVS.

Amir, you first swear up and down that evidence does not exist, and then when I quote a tiny part of it that is not even about its thesis, you chastise me for quoting it. In the process you admit that you knew about it all along.

Then you argue with it!

Amir, one lesson from all of this is that you will argue against *anything*, and conceal any relevant evidence that you already know in order to bolster your argument.
post #35 of 761
You guys just saved me a lot of money. Thanks! I guess good masters and CD quality really are "as good as it gets".

Does anything in the report (which I skimmed) seem to indicate that there is a quality difference in DACs?
post #36 of 761
Quote:
Originally Posted by Walk_Good View Post

I agree, you can't hear the difference and am happy to read that others agree as well if one believes they can hear a difference, they should load up Foobar2K, install ABX Comparator to try a double-blind listening test between two tracks for themselves. The only reason I could see 24-bit/192kHz format is for mastering/mixing the original recordings.

Edit: BTW both are free software

Perhaps for studio archival works for future use or posterity?
post #37 of 761
Quote:
Originally Posted by Walk_Good View Post

I agree, you can't hear the difference and am happy to read that others agree as well … if one believes they can hear a difference, they should load up Foobar2K, install ABX Comparator to try a double-blind listening test between two tracks for themselves. The only reason I could see 24-bit/192kHz format is for mastering/mixing the original recordings.

Edit: BTW both are free software

99% of the people running playback software on their pc do not have the proper stack/drivers to play a 192khz/24bit audio file unmolested... you might be in that 99%... in these cases, something in the stack is decimating audio. In other words, in your case, there may be no difference.
post #38 of 761
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Originally Posted by arnyk View Post

Amir, you fell into one of my traps, again! The fact that you could recognize this report from a tiny quote of it shows something about your comments here on AVS.

I didn't "recognize" it because you didn't provide appropriate reference with a link to the paper. So I used Google to search for it and as soon as I saw the title and authors of the paper, realized what it was and that it did not support your position or Monty's.

Putting aside the fact that we are adults and should not be laying "traps" for each other, I fail to see what trap you did leave for me. That I can use Google and have read technical articles in this area? My admission here is a bad thing?

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Amir, you first swear up and down that evidence does not exist, and then when I quote a tiny part of it that is not even about its thesis, you chastise me for quoting it. In the process you admit that you knew about it all along.

I didn't say evidence didn't exist. I said I didn't know about it because Monty's article didn't provide the reference. You said I should have known, only to post a paper which had nothing to do with the question I raised.

I don't know why you are surprised that I questioned you posting a paper that invalidates your thesis.

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Amir, one lesson from all of this is that you will argue against *anything*, and conceal any relevant evidence that you already know in order to bolster your argument.


You started the argument Arny and now you complain about arguing? I post Bob's report and its conclusion as an answer to someone else. You post a long response, saying it is "corporate white paper that has no standing as an industry standard or recommendation." And that you put value on something published at AES. Never mind that we are discussing an online article in this thread which has is not published that way. You follow that with confirmation of Monty's claim that ultrasnoics are bad for us.

I provide reference that Bob's paper was indeed published at AES. Any AES member could have searched and downloaded it in a few seconds. I am sitting here still with no answer on which listening test confirmed IMD distortion yet you were in total agreement with him with that "enough said" statement.

If you don't want an argument, then please don't put down work from respected industry experts like Bob, and don't back to use your phrase, "factoids" with no reference which you can't substantiate let alone there being a lot of examples of it.
post #39 of 761
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Does anything in the report (which I skimmed) seem to indicate that there is a quality difference in DACs?

No.
post #40 of 761
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Originally Posted by amirm View Post

I didn't "recognize" it because you didn't provide appropriate reference with a link to the paper.

Except you did recognize the article in your first response to the post, and without the reference. Amir, now you are denying clearly evident facts!

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So I used Google to search for it and as soon as I saw the title and authors of the paper, realized what it was and that it did not support your position or Monty's.

As usual Amir, you are changing the subject of our conversation in a deceptive way, which is not how sincere adults behave.

Amir, the topic of the discussion you just sloughed is whether or not IM in components is likely to cause audible artifacts with high sample rate music.

Amir, I produced a paper where the some of the author's statements clearly supported my position. You are now trying to change the topic away from that and towards the main thesis of the paper. I'm not going to let you pull that stunt again!

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Putting aside the fact that we are adults and should not be laying "traps" for each other, I fail to see what trap you did leave for me.

The trap you fell into Amir was that you admitted that you knew that it is well known that IM in components is likely to cause audible artifacts with high sample rate music, immediately after you denied that was possible.

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Originally Posted by amir View Post

I didn't say evidence didn't exist.

You said that the effect didn't exist.

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Originally Posted by amir View Post

I said I didn't know about it because Monty's article didn't provide the reference.

Amir, you were kind enough to let me trap you into admittng that you were intimately familiar with an article that clearly stated that IM in components is likely to cause audible artifacts with high sample rate music.

Amir, if your first response left any questions about your recent obfuscations unanswered, your second post removes all remaining doubts. You hve now admitted that you knew that it is well-known that IM in components is likely to cause audible artifacts with high sample rate music. Yet you denied it on completely ridiculous grounds - that the specific paper we were talking about didn't footnote its claim about that to your satisfaction.

It is very irritating to hold an conversation with someone who knows the relevant facts but denies them whenever it suits him. Life is too short!
post #41 of 761
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Originally Posted by djkest View Post

You guys just saved me a lot of money. Thanks! I guess good masters and CD quality really are "as good as it gets".

Does anything in the report (which I skimmed) seem to indicate that there is a quality difference in DACs?

There's no doubt that there are sound quality differences among some DACs. For example, the DACs that drive the headphone jacks in PC CDROM drives have historically been technically substandard enough that they had audible defects.

The problem is that many people are claiming all sorts of things about DACs sounding different that just don't stand up to careful inspection and testing.
post #42 of 761
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Originally Posted by mlknez View Post

99% of the people running playback software on their pc do not have the proper stack/drivers to play a 192khz/24bit audio file unmolested... you might be in that 99%... in these cases, something in the stack is decimating audio. In other words, in your case, there may be no difference.

It is good to keep people reminded that playing high sample rate files on Win7 and Vista machines can be less than straight foreward.

IME 99% is a very high estimate. There are still tons of XP machines around, and IME they rarely if ever molested 24/192 files.

Even for Vista and Win 7 machines, there's an easy path to bit-perfect playback of high sample rate files that the recommended software (FOOBAR) supports, known as ASIO.
post #43 of 761
Bob Stuart's article doesn't seem outrageous at all. My read is that his opinion, an educated opinion at that, is that 16 bits is plenty with dithering and shaping, but 44.1K is a bit tight. He states that having a sampling rate 1.5x higher than Nyquist rate would allow better behaved filters to be used. Later he basically says that using multiples of the two current standards would be more practical, and thus supports 88.2 and 96Khz. He also mentions that most consumer products do a poor job of truncating 24 bits, thus supports 24 bit in the studio but 20 bits for distribution. Furthermore, he recommends loss-less compression for data integrity and keeping the file size down.

My question or maybe it's an observation, is that HDtracts sells a bunch of old analog recordings at 88/24 or even 192/24. Seems a bit optimistic that the original recordings have that much data in them. Do you really need 88/24 or 192/24 to convey old analog reel-reel music?
post #44 of 761
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Originally Posted by arnyk View Post

The trap you fell into Amir was that you admitted that you knew that it is well known that IM in components is likely to cause audible artifacts with high sample rate music, immediately after you denied that was possible.

I said that I had read that paper and it was about the ability of people to appreciate ultrasonics. There is no listening test in there for back this statement from Monty: "the effect is very slight, but listening tests have confirmed that both effects can be audible." I have asked twice for that evidence and you have not shown it.

A listening test of IM distortion with ultrasonics is a specific thing. It is clear you don't have such a report yet you believe second hand claim of its existence. And you cite evidence of support in the Hypersonics paper, yet the core thesis of that undermines your entire position that we don't need anything better than the CD.

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You said that the effect didn't exist.

That's not correct Arny. This is what I said and I quote:
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Originally Posted by amirm View Post

I can't find any reference he provides for that. Maybe there are such tests and if so, I love to read them but for now, you don't say there are listening tests and not at least mention them by name.

I faulted him for making a reference to a test that he doesn't provide a reference to and you giving him a high five. How can you believe a claim like this with no back up or details about the test?

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Amir, you were kind enough to let me trap you into admittng that you were intimately familiar with an article that clearly stated that IM in components is likely to cause audible artifacts with high sample rate music.

That is not what the article says. it says this: "In addition, inter-modulation distortion may differentially affect LFCs." "May" is not the same as "likely." And at any rate, is not a listening test of IMD as I repeatedly ask, and keep getting these deflections.

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Amir, if your first response left any questions about your recent obfuscations unanswered, your second post removes all remaining doubts. You hve now admitted that you knew that it is well-known that IM in components is likely to cause audible artifacts with high sample rate music. Yet you denied it on completely ridiculous grounds - that the specific paper we were talking about didn't footnote its claim about that to your satisfaction.

To my satisfaction? You read Bob Stuart's paper. It has *two* pages of references and you claimed what he had written was factoids and opinions. Marty says there is a listening test proving audibility of IMD ultrasonics and after three posts, you can't cite it yet you accepted it a face value? What if the test didn't exist? What if it was sighted? What if it was single and not double blind? What if there were mistakes in it? You are good with someone stating the results of a listening test like that and have it be that?

Truth is that if he had said the listening tests had shown that CD wasn't good enough, you would be up in arms about lack of detail. But have it say what you want to hear and you complain about someone else asking for detail? Where is your objectivity if I may ask?

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It is very irritating to hold an conversation with someone who knows the relevant facts but denies them whenever it suits him. Life is too short!

Life is too short. So how about next time not jumping in, claiming a well written authoritative paper that goes on for some 37 pages is not corporate white paper. Doing a bit of searching on AES web site to see if published there before saying it isn't (and joining as a member if you are not). And not backing unsubstantiated measurements and hearsay claims of listening tests. Then grief would not be there. OK, this is AVS so grief is inevitable but you get the picture.
post #45 of 761
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Originally Posted by mlknez View Post

... something in the stack is decimating audio. In other words, in your case, there may be no difference.

Humans don't actually hear ultrasound, no matter how amazing one thinks his/her hearing is. http://theaudiocritic.com/plog/index...eId=4&blogId=1 or http://drewdaniels.com/audible.pdf
post #46 of 761
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Originally Posted by Swampfox View Post

Bob Stuart's article doesn't seem outrageous at all.

Umm, too you. Here's reality - Stuart's paper started out in the late 1980's as an attempt to fix the mistakes that were made in the original RedBook standards. It appears that he gave it a retread and tried to get it to fly 10 years later in the late 1990s. Eventually his ideas got some traction and the major recording and electronics companies blew a few hundred million on SACD and DVD-A which may have overkilled his idea, but they were based on his basic thesis that significant audible improvements over RedBook CD format were not only possible, but likely to be commercial successes. Didn't happen in the mainstream marketplace and 100's of millions were lost and careers were seriously damaged. People in high places got fired for hitching their company's wagon(s) to the DVD-A and SACD stars.

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My read is that his opinion, an educated opinion at that, is that 16 bits is plenty with dithering and shaping, but 44.1K is a bit tight.

Sounds great on paper, but fails the sniff test when you do good listening tests. Stuart has had the resources for over 35 years (Meridian was founded in 1977) to come foreward with even just one proper listening test that showed that what he was talking about actually did what he kept claiming - provide superior sound quality.

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He states that having a sampling rate 1.5x higher than Nyquist rate would allow better behaved filters to be used. Later he basically says that using multiples of the two current standards would be more practical, and thus supports 88.2 and 96Khz. He also mentions that most consumer products do a poor job of truncating 24 bits, thus supports 24 bit in the studio but 20 bits for distribution. Furthermore, he recommends loss-less compression for data integrity and keeping the file size down.

As I point out below, if the above is true and I think it is, Stuart wants people to use almost 2 bits for every bit that would be required in the minimal case.

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My question or maybe it's an observation, is that HDtracts sells a bunch of old analog recordings at 88/24 or even 192/24. Seems a bit optimistic that the original recordings have that much data in them. Do you really need 88/24 or 192/24 to convey old analog reel-reel music?

Of course not. I can actually construct a technical argument that you need 48 KHz sampling to do a great job of capturing the music on a 15 ips half track analog tape master. But, it all falls apart when you include the human ear.

Do you need 24 bits or 20 bits to capture the music on that half-track master? Don't be silly! The noise floor on those great-sounding old tapes is in the 12-13 bit range depending on how you do the digital. With aggressive noise shaping, 11 bits might work.
post #47 of 761
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Originally Posted by Walk_Good View Post


Humans don't actually hear ultrasound, no matter how amazing one thinks his/her hearing is. http://theaudiocritic.com/plog/index...eId=4&blogId=1 or http://drewdaniels.com/audible.pdf

you missed my point I was just saying if your stack was setup correctly you may or may not be able to hear it but most people do not have the hardware or the software to even play those files properly let alone hear a difference.
post #48 of 761
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Originally Posted by mlknez View Post

you missed my point I was just saying if your stack was setup correctly you may or may not be able to hear it but most people do not have the hardware or the software to even play those files properly let alone hear a difference.

I got it and do agree with your point, that's why I didn't respond to that part but rather to the "may or may not be able to hear."
post #49 of 761
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Originally Posted by mlknez View Post

you missed my point I was just saying if your stack was setup correctly you may or may not be able to hear it but most people do not have the hardware or the software to even play those files properly let alone hear a difference.

I think you are right to keep on reiterating this point. No matter what I believe about these various parameters, I more strongly believe that people should do clean evaluations.

When I was doing things like this I measured the frequency response of my test setups so I knew for sure that whether it was audible or not, it came out of the output jack.
post #50 of 761
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Originally Posted by arnyk View Post

When I was doing things like this I measured the frequency response of my test setups so I knew for sure that whether it was audible or not, it came out of the output jack.

Which unfortunately seems to have not been doing in Meyer and Moran with regards to the test material or hardware they used. Despite this, they had one tester who got 8 out of 10 right, detecting the high resolution source. Wonder if the test was completely proper, how much higher it would get.
post #51 of 761
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Originally Posted by amirm View Post

Which unfortunately seems to have not been doing in Meyer and Moran with regards to the test material or hardware they used.

As far as the test material goes, it is true that M&M did not cover the possibility of malfeasance on the part of the media suppliers, which unfortunately was widespread, it seems.

The evidence we have now suggests that were selling old shoes in new boxes. Everybody's ears were fooled, even the goldenest of the goldenest of the golden eared music reviewers. The in-house and hired gun mastering engineers must have been fooled as well. The problem was outed by measurements, because only measurements were a reliable indicator of the presence or absence of music > 20 KHz. In a way, here we have the blindest test of all and it too was negative for audible differences.

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Despite this, they had one tester who got 8 out of 10 right, detecting the high resolution source. Wonder if the test was completely proper, how much higher it would get.

Comments like this make anybody who has actually worked with non-trivial data sets smile. You've always got some outlyers. If you really understand statistics, you expect them and give them the credibility they deserve, which is nothing special.

We learned about apparent golden ears back in the late 1970s. Guess what happens to your golden ears when you ask them to develop more data points? They converge to the mean!

Ever flip a coin 1,000 or 10,000 times? Been there, done that. You get some incredible runs of heads after heads after heads and tails after tails after tails. Unless the test is biased, convergence to the mean is virtually guaranteed.

I'd like to see the M&M tests rerun with all of the old shoes thrown out as an intellectual exercise. But, given the other relevant testing that has already been done, positive outcomes are unlikely.
post #52 of 761
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Originally Posted by arnyk View Post

Umm, too you. Here's reality - Stuart's paper started out in the late 1980's as an attempt to fix the mistakes that were made in the original RedBook standards. It appears that he gave it a retread and tried to get it to fly 10 years later in the late 1990s. Eventually his ideas got some traction and the major recording and electronics companies blew a few hundred million on SACD and DVD-A which may have overkilled his idea, but they were based on his basic thesis that significant audible improvements over RedBook CD format were not only possible, but likely to be commercial successes. Didn't happen in the mainstream marketplace and 100's of millions were lost and careers were seriously damaged. People in high places got fired for hitching their company's wagon(s) to the DVD-A and SACD stars.

That is remarkable progress Arny. You went from yesterday not knowing his paper was published at AES and seemingly not aware of it, to all of sudden knowing all about it and blame Bob for existence of DVD-A and SACD? Even after I explained his position was against SACD, you pin that format on him too? How about blaming him for the current recession we are having?

The reasons those formats failed are clear and have nothing to do with Bob. Consumers have shown incredible apathy for audio/video fidelity. They simply will not pay for them, or put quality ahead of convenience. Neither DVD-A or SACD allowed ripping of their content, coming at an era where you could do that. Nor would they allow consumers to buy individual tracks as they could by either stealing the bits or buying them from iTunes. And of course prices were higher. For *general* consumers, all of these issues soundly trump quality differences and hence the formats failed.

As another counterpoint, both of these formats allow for multi-channel playback. Surely you are not going to say consumers can't tell the difference between 2-channel and multi-channel music. Yet, even though that differentiation existed and clearly identifiable in blind testing, it didn't save either format. Clearly that was not enough to trump lower value and lack of convenience.

It is important to make another point. There is a temptation here to extrapolate the topics we are talking about to general public. That is wrong. This is an enthusiast forum. We don't care what the general public thinks of our hobby or desires for fidelity. Take video. My wife would not buy anything but DVDs. They are cheaper and she finds them on sale at the stores she shops. I am the only one buying blu-rays and at extra cost. To her, DVD is "good enough" as to not be worth spending anything extra for quality. Truth to be told, I watch those DVDs with her and if the story and acting is compelling, I enjoy them just the same. By your logic, this must mean that there is no fidelity difference that is observable in blind tests against DVD whereas we know the reality is otherwise. Mass consumer preference for a format is not the same as us voting for what is improved fidelity or not.

If I asked die-hard audiophiles if they would buy either one of these formats they would say yes. But sadly, they do not make a reasonable enough market to enable distribution of higher fidelity content. So the formats did not die because the fidelity wasn’t there necessarily but because there is not a mass market for it. With HD Tracks selling high resolution music, the bits that were in these formats may be coming back anyway.

So no, Bob is not the reason either one of these formats got created, or failed. The industry had a format war on its hand and Bob was doing its best to speak about his wisdom after nearly two decades of designing such gear at that time. He didn't work for Sony and Philips who wanted to advance their patent position which was lost on the CD (time period was expiring). Nor was he part of the Panasonic, Toshiba and crew who wanted to advance the same for DVD-A. You want to know why these formats existed, you need to look in that direction .

As I noted earlier, despite lack of involvement from Bob and his company, his company's lossless compression became part of HD DVD and then Blu-ray. We should be thankful of his contributions rather than putting him down just because he dared to say we need to go a hair past CD to assure inaudibility of the distortion in our distribution format. He strives for excellence and we need more people like him, not less.
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Sounds great on paper, but fails the sniff test when you do good listening tests. Stuart has had the resources for over 35 years (Meridian was founded in 1977) to come foreward with even just one proper listening test that showed that what he was talking about actually did what he kept claiming - provide superior sound quality.

His job isn't the same as yours Arny. Your goal is how crappy we could make audio until folks can hear distortion. His job is to provide a specification that has a design margin that allows us to establish inaudibility without much guesswork. That is a higher bar than you strive. By your standard, when building a bridge, we should go by the average weight of all the cars going on it, rather than increasing that by a safety margin. If we are talking general public, your standard is more than enough. Indeed it is too good as consumers are good with lossy compression even though we know that doesn’t achieve full transparency.

That is beside the fact that if Bob had documented the tests you ask about, you would find 1000 faults with it as to dismiss the results. Yet if Monty says there is some listening test that proves having higher bandwidth is bad for us, you give him high five without even asking for the test details. The mere mention of what you want to hear is good enough evidence. But 37 page paper written and presented at AES is not worth anything but to be used to bad mouth one of the industry leaders in digital audio.

Here is an example test you and I discussed:

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http://old.hfm-detmold.de/eti/projek...paper_6086.pdf

"DVD-Audio versus SACD
Perceptual Discrimination of Digital Audio Coding Formats
Listening Comparison Test between DSD and High Resolution PCM (24-bit / 176.4 kHz)

by
Dominik Blech and Min-Chi Yang
Erich-Thienhaus-Institute (Tonmeisterinstitut), University of Music Detmold, Germany
"

The test was ABX and designed to see if anyone could tell the two sources apart. Almost no one did except for four people:


"The four highest scores fell into the region of “critical probability.” This amounted to only 2.76% of all the tests. These four tests were carried out by four separate listeners, all of whom chose stereo music examples, and in all four cases headphones were used—thus excluding the influence of the listening environment to the greatest possible extent."

So we have four people hearing the difference between SACD and DVD-A. Your counter was here: http://avsforum.com/avs-vb/showthrea...2#post20277042 saying the test was done in 2004 and M&M test was in 2007 so the latter result is more valid. Never mind that the M&M test had nothing to do with comparing SACD to DVD-A, and didn't follow the same protocol or anything like it. But hey, you like its conclusions better so you ran with it. My answer is a few posts later: http://avsforum.com/avs-vb/showthrea...9#post20277189

Additionally, as I just noted, in M&M test, one person got 8 out of 10 right. If I am building a format that I claim to be fully transparent to the source, I wouldn't want anyone getting such a high score. The fact that this statistic doesn't rise to 95% wouldn't be enough for me. I would want the format for high-end enthusiasts to do better than that. Again, the target here is not the general public so it is not important to me that 50 other people got lower scores. I would have taken that one person aside and tested him some more rather than summing everyone together and declare “50-50” results.
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As I point out below, if the above is true and I think it is, Stuart wants people to use almost 2 bits for every bit that would be required in the minimal case.

You think it is? You didn't read the report as Swampfox did? Did you read Swapfox’s proper summary of how he is rounding up to the next sampling rate since we don't have 58 Khz as a valid option? How about the fact that Bob goes down from 16 to 14 bits? He doesn't get credit for that? You are forever non-objective when you look at evidence like this Arny .
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Of course not. I can actually construct a technical argument that you need 48 KHz sampling to do a great job of capturing the music on a 15 ips half track analog tape master. But, it all falls apart when you include the human ear.

Once more, enthusiasts want all that existed there. If that requires 48 Khz, then you don't get to chop down the content for them because you have this M&M test in your pocket. If you claim to have a copy of the master tape in digital, then you better deliver that as is. What is so wrong with doing that Arny?

As you correctly imply, Reel to Reel does not have a brick wall filter on its frequency response at 22 Khz. So capturing it at 44.1Khz may indeed leave some of the response on the table. Why not capture that and give it to the discriminating consumer? Why go on and on, advocating a lesser standard?
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Do you need 24 bits or 20 bits to capture the music on that half-track master? Don't be silly! The noise floor on those great-sounding old tapes is in the 12-13 bit range depending on how you do the digital. With aggressive noise shaping, 11 bits might work.

For others who don’t know what we are talking about, when digital systems use fixed bit depth, you create distortion since analog waveforms do not have such steps. The way to solve this is to add some amount of random data in the form of noise to the signal prior to digitalizing it. That converts distortion into noise which is a good thing. What is not a good thing is that we have now raised the noise floor of our system relative to the source. Noise shaping says instead of adding noise that has equal power in the audible frequency band, we make it so that it has the least amount where the ear is most sensitive and more of it where it is not.

Given the above, the best use of noise shaping is when you have bandwidth above 20 Khz to stuff the noise there. With 44 Khz sampling, your response stops at 22Khz so you are now essentially forced to put the quantization noise in the audible band. This is one of the other reasons it is better to have some headroom in our sampling rate as to give us a place to “park” these dither noise. If you used 88 Khz for example, you now have 50% more bandwidth to push the noise into.

The above is the type of analysis that Bob does in his paper (and then some) to arrive at his recommendations. He puts thought in there combined with excellent grasp of technology and science. Whether you agree with this conclusions or not, it is worth a read. As I have said, I have always used his paper to prove that we don’t need astronomical sample rates and bit depths for transparency. Its use in reverse by Arny is very odd.
post #53 of 761
Quote:
Originally Posted by arnyk View Post

Eventually his ideas got some traction and the major recording and electronics companies blew a few hundred million on SACD and DVD-A which may have overkilled his idea, but they were based on his basic thesis that significant audible improvements over RedBook CD format were not only possible, but likely to be commercial successes. Didn't happen in the mainstream marketplace and 100's of millions were lost and careers were seriously damaged. People in high places got fired for hitching their company's wagon(s) to the DVD-A and SACD stars.

You really can't blame Stuart for any of that. The executives that made the decisions are 'big boys'. The decision was based upon a perceived market, they took a risk, the market wasn't there, they lost. I'm OK with that, it's how free markets work.

Quote:


Sounds great on paper, but fails the sniff test when you do good listening tests. Stuart has had the resources for over 35 years (Meridian was founded in 1977) to come foreward with even just one proper listening test that showed that what he was talking about actually did what he kept claiming - provide superior sound quality.

I'm fairly dubious about his claim that 'some individuals can hear 24kHz'. Maybe a small fraction of infants can, but I'd like to see data on the percentage of adults that can hear 20K, let alone 24K. Frankly, most adults are lucky to hear much above 16K.

Quote:


As I point out below, if the above is true and I think it is, Stuart wants people to use almost 2 bits for every bit that would be required in the minimal case.

I don't get the point. What's the cost to the end consumer in having excess capacity? The cost of the DAC is a small percentage of the overall costs of a player. The storage media isn't prohibitive. The material isn't produced at 16/44.1. The way the data is currently stored is obsolete because modern loss-less codecs are more efficient and provide data integrity.
So who cares if we waste bits.

I do have a problem with dishonest marketing, but that has nothing to do with engineering a system that has more than ample 'headroom'.
post #54 of 761
Quote:
Originally Posted by Swampfox View Post

I don't get the point. What's the cost to the end consumer in having excess capacity? The cost of the DAC is a small percentage of the overall costs of a player. The storage media isn't prohibitive. The material isn't produced at 16/44.1. The way the data is currently stored is obsolete because modern loss-less codecs are more efficient and provide data integrity.
So who cares if we waste bits.

If wasting bits on our current ginormous desktop hard hard drives were the only issue, I'd settle for hi-rez right now.

But, isn't the latest iPad priced like this?

"The 16GB model can be grabbed in the U.S. for $499. Users who demand more on the storage capacity front might prefer the 32GB or 64GB version. Both these devices come tagged with price labels of $599 and $699, respectively."

Let's do the arithmetic: Pre-Thailand flood 1 TB hard drives were $69.95 for top quality, retail-boxed, 7200 rpm large cache models - that is $0.07 per GB.

But, put that same GB into the latest iPad, and a GB of disk space runs $6.25 or $3.125, depending on your budget. Ironically, the iPad drive space is flash, which currently runs around $1 a GB in most other forms.

Then there is the hi-rez premium for buying media. HDtracks wants like $25 for a 24/192 album, while MP3 albums start out as low as $2.95 or less at Amazon.
post #55 of 761
Quote:
Originally Posted by arnyk View Post

If wasting bits on our current ginormous desktop hard hard drives were the only issue, I'd settle for hi-rez right now.

But, isn't the latest iPad priced like this?

"The 16GB model can be grabbed in the U.S. for $499. Users who demand more on the storage capacity front might prefer the 32GB or 64GB version. Both these devices come tagged with price labels of $599 and $699, respectively."

Let's do the arithmetic: Pre-Thailand flood 1 TB hard drives were $69.95 for top quality, retail-boxed, 7200 rpm large cache models - that is $0.07 per GB.

But, put that same GB into the latest iPad, and a GB of disk space runs $6.25 or $3.125, depending on your budget. Ironically, the iPad drive space is flash, which currently runs around $1 a GB in most other forms.

Then there is the hi-rez premium for buying media. HDtracks wants like $25 for a 24/192 album, while MP3 albums start out as low as $2.95 or less at Amazon.

My 'way ginormous' NAS stores archival copies of music and terabytes worth of movies. In my house, I stream content to devices that can play back the content I want to view or hear. I convert music to mp3 for playing on my i-devices and other portable devices. I would guess most enthusiasts do the same. Personally, I see no compelling reason to have high res content on a portable device.
post #56 of 761
Quote:
Originally Posted by amirm View Post

For others who don't know what we are talking about, when digital systems use fixed bit depth, you create distortion since analog waveforms do not have such steps. The way to solve this is to add some amount of random data in the form of noise to the signal prior to digitalizing it. That converts distortion into noise which is a good thing. What is not a good thing is that we have now raised the noise floor of our system relative to the source. Noise shaping says instead of adding noise that has equal power in the audible frequency band, we make it so that it has the least amount where the ear is most sensitive and more of it where it is not.

Amir recites yet another Audiophile Myth like it was revealed truth - the myth that "...when digital systems use fixed bit depth, you create distortion since analog waveforms do not have such steps".

In fact all credible digital converters use dither or other means for randomizing quantization distortion, which results in *no* distortion due to "steps".

Obviously, Amir has never attached a piece of test equipment like a 'scope to the analog output of any normal piece of digital audio gear, because no matter what tests you run, there are no relevant traces of those much-feared "steps".

For example, check out Figure 3 on page 3 of http://www.ti.com/lit/an/slea048/slea048.pdf which shows the output of a DAC chip running at a 48 KHz sample rate. If there were steps present in its output, we might expect to see spikes at 48 KHz, 96 KHz, etc. Instead we see no deviations from a normal random noise floor.
post #57 of 761
My recollection of what Bob Stuart was proposing was that it had something to do with a new standard that just happened to be his own suggesting there was money to be made for him and his company. Is my memory faulty here?
post #58 of 761
Quote:
Originally Posted by arnyk View Post


For example, check out Figure 3 on page 3 of http://www.ti.com/lit/an/slea048/slea048.pdf which shows the output of a DAC chip running at a 48 KHz sample rate. If there were steps present in its output, we might expect to see spikes at 48 KHz, 96 KHz, etc. Instead we see no deviations from a normal random noise floor.

You do know that that is a delta-sigma DAC, right?
post #59 of 761
Quote:
Originally Posted by Chu Gai View Post

My recollection of what Bob Stuart was proposing was that it had something to do with a new standard that just happened to be his own suggesting there was money to be made for him and his company. Is my memory faulty here?

Enlightened self-interest.
post #60 of 761
Amir;

Anyone can see the difference between a blu-ray and DVD. Your point is akin to saying room has no impact on the sound. Nobody is arguing otherwise.
Your wife can see the difference between DVD and blu-ray, but she just doesn't care to pay for that difference. That is entirely different than not being able to see the difference.

As far as DVD-A and SACD. I don't believe anyone can hear the difference between them and a CD as long as they are identically mastered and level matched. That was one of the reasons why they died. Yes it is true consumers did not care for quality, but there was no extra quality to begin with. With that token blu-ray should have died too, yet it is surviving. Not very successfully but surviving because there is a quality difference. Nobody can say that for DVDA and SACD.
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