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'Mastered For iTunes' guidlines from Apple Effects Pedals, Units & Accessories
Old 15th March 2012
  #331
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Old 15th March 2012
  #332
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Quote:
Originally Posted by optimax4000 View Post
So how about let's just put our minds and energy toward eliminating lossy audio as an issue, instead of pretending that we can somehow "make it better".
Do you really think that mastering engineers have the power to eliminate lossy audio?
Lossless is the way to go for sound quality. Yes, absolutely yes.
But lossy audio is a reality. Now, today.


Old 16th March 2012
  #333
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Quote:
Originally Posted by Laarsø View Post
This is not a scientific measurement of audio fidelity. It's a head count of who can be fooled.
From the ITU-R BS.1284-1:
"9. Statistical treatment of data
The subjective data should be processed to derive the mean values and confidence intervals. This will describe the data and, if the resulting discrimination is inadequate to satisfy the objectives of the test, further processing should be carried out. The methods of Recommendation ITU-R BS.1116, § 9 may be used. In general, statistical expertise will be required to analyse the data."

You can download it from:
BS.1284

Who are ITU:
"ITU membership represents a cross-section of the global ICT sector, from the world's largest manufacturers and carriers to small, innovative players working with new and emerging technologies, along with leading R&D institutions and academia."

Quote:
Originally Posted by Laarsø View Post
A perceptually-weighted mangling that can fool a crowd of listeners is reminiscent of Enrico Caruso endorsing the Victrola as indistinguishable from live music.
Do you think that a 24/96 file it's indistinguishable from live music?
So transducers, analog -non linear- preamps and A/D converters are perfect.
Sorry. I play piano and there is no recording-playback device capable of reproducing the same live sound and vibrations. (Well, I don't know it).

Quote:
Originally Posted by Laarsø View Post
Just take Aliyah's song, "Try Again," and convert the uncompressed extraction from your store-bought CD to AAC. Then convert the AAC to .wav (or .1/.2, etc...), line them up in two panels of your DAW and toggle between the panels while playing both versions back, in sync. The snare and kick and general high end is so much more exciting and open with the uncompressed source, I don't know how someone can mistake, even against 320 kb/sec/stereo AAC.
Because there're people that only listen to music and not to the "sound of the music".
Because you have a "sound quality" education and your brain is "tuned" to do this analysis.
Music cognition is not Sound cognition.
To appreciate the details you need to know where to put your attention.
Normal people don't have this backgroung. They only listen to music... except if something important fails: a lot of distortion, narrow frequency range, low volume...

And also, maybe, becasue the mastering engineer has not compensated for lossy. Do you know it?

Quote:
Originally Posted by Laarsø View Post
I don't believe in listening tests - since they only test the taker, rather than the audio
And what's the audio without a "taker"?
Next sampling frequency: 69 MHz (... looks sexy... perfect for soul music).


Old 16th March 2012
  #334
j_j
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Quote:
Originally Posted by SweetLossy View Post
This does work for lousy loudspeakers, it's not the same as the real thing at all, but first you have to have the original bass frequencies in order to do this. If somebody has removed them already ...
Old 16th March 2012
  #335
j_j
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Quote:
Originally Posted by Laarsø View Post
OkMine is only perceptual codec of your level of quackery.
I require you to retract this egregious, false example of professional defamation.

The rest of your uninformed, ignorant screed is not worth addressing.
Old 16th March 2012
  #336
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Quote:
Originally Posted by j_j View Post
screed
that the good ****

a-screed
Old 16th March 2012
  #337
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Quote:
Originally Posted by j_j View Post
I require you to retract this egregious, false example of professional defamation.

The rest of your uninformed, ignorant screed is not worth addressing.
It might help to think of Laarsø as the entropy generator of this forum.

I do.


DC
Old 16th March 2012
  #338
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Quote:
Originally Posted by Bob Olhsson View Post
It's important to understand that what JJ considers a listening test and what the ABX/Hydogen Audio skeptics crowd considers a listening test are two very very different things.
Perhaps JJ can explain what he considers a listening test and how it's different from the Hydrogenaudio standpoint.
I was somehow under the impression they were not that different.
Old 16th March 2012
  #339
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Quote:
Originally Posted by j_j View Post
I require you to retract this egregious, false example of professional defamation.

The rest of your uninformed, ignorant screed is not worth addressing.
I agree that it's a "false example of professional defamation." Everything Laarsø said, above, therefore, stands. Only _true_ examples, thereof, such as your bile-encrusted rejoinders, ought to be edited, yes?

As for the insults, keep them comink. Laarsø has laid back master black belt in cappin' the rap.

Cheersø,
Laarsø
Old 16th March 2012
  #340
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Quote:
Originally Posted by dcollins View Post
It might help to think of Laarsø as the entropy generator of this forum.

I do.


DC

Au contraire. Whereas Laarsø is negentropy source for premastering with honesty. Everyone who says she is "mastering," but does so without a lathe or lbr, misspeaks. Sorry.




Cheersø,
Laarsø
Old 16th March 2012
  #341
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Quote:
Originally Posted by SweetLossy View Post
...ITU-R BS.1284-1
I C UR BS! (;


Again, I ask, just how many SI tingles are formed on the nape of the listener to AAC version versus uncompressed LPCM source file? We need numbers of scientific units of measurement. To say, "It sounds identical," or to say, "I think I hear a difference," is meaningless. It's not a number (of standard units).

Quote:
Originally Posted by SweetLossy
Do you think that a 24/96 file it's indistinguishable from live music?
Has to be played on the right loudspeaker with the right amplifier and in an anechoic chamber... _and_ the instrument has to be played in that chamber, for the comparison to work. Then you will be fooled, if blindfolded and sufficiently bribed (I mean, groped, I mean, honest). Yes.



Quote:
Originally Posted by SweetLossy
Because there're people that only listen to music and not to the "sound of the music".
Because you have a "sound quality" education and your brain is "tuned" to do this analysis.
Music cognition is not Sound cognition.
To appreciate the details you need to know where to put your attention.
Normal people don't have this backgroung. They only listen to music... except if something important fails: a lot of distortion, narrow frequency range, low volume...

Don't sell short the shiny happy non-studio people. I am defending also their subconscious minds as well as their conscious awareness. The music should sound so good that repeated listens reveal more and more nuance or subtlety.

Seriously, the only reason lossy media beats CD is convenience and impulse click-buys.


Quote:
Originally Posted by SweetLossy
And also, maybe, becasue the mastering engineer has not compensated for lossy. Do you know it?

A "mastering engineer" has no business touching a lossy codec in her job. (She makes either the lacquer sound disc, which goes to parts, or she makes the glass master, which also goes to parts.) It is, rather, the premastering clerk who might be asked to decimate a perfectly merchantable CD. (This is why words matter. One misunderstanding snowballs into a tangled web of downloads.

Next.)



Quote:
Originally Posted by SweetLossy
And what's the audio without a "taker"?
Next sampling frequency: 69 MHz (... looks sexy... perfect for soul music).
Actually, it doesn't look so sexy at that speed. As Dan Lavry points out, the low end loses accuracy starting at sampling rates above ~55 kHz Fs due to the need for settling between pulses. So, slow down your Mustang, Sally.


Cheersø,
Laarsø
Old 16th March 2012
  #342
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Quote:
Originally Posted by Laarsø View Post
Again, I ask, just how many SI tingles are formed on the nape of the listener to AAC version versus uncompressed LPCM source file? We need numbers of scientific units of measurement. To say, "It sounds identical," or to say, "I think I hear a difference," is meaningless. It's not a number (of standard units).
And when you've measured your difference, how do you know it's audible?

Do you just guess, or do you refer to data on whether that magnitude of difference is audible, data usually acquired through listening tests.

You seem to have a strange idea of how proper listening tests are performed.

For example a double blind ABX does not determine whether someone thinks they can tell a difference, it determines whether they actually can or can not (under the circumstances of the test). The MEASURED results of the test (the number of times they actually got it right) can be used to determine a probability that they are actually hearing a difference, that lets us determine an audibility limit for that individual. Sampling a properly selected group of individuals lets us determine a probable limit for audibility in humans as a whole.

It's scientific measurement and analysis, not guesswork, and it's not people saying "I think I hear a difference", in fact it's specifically designed to eliminate the "think" from the equation.
Old 16th March 2012
  #343
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Quote:
Originally Posted by optimax4000 View Post
The importance of "audibility" is sometimes overrated in these discussions, as are the results of various types of testing. : )
When the subject is audio for humans, what can possibly be more important than audibility to humans?
Quote:
It also seems to me that the phenomena being observed do not really submit to all the "rules", "regulations", and / or limitations that some are trying to impose.
Nobody is trying to "impose" rules, regulation or limitations, they're trying to ascertain what limitations actually exist.
Old 16th March 2012
  #344
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Quote:
Originally Posted by optimax4000 View Post
As they say, "If you have to ask ............".
erm... "it means you'd like an answer" ?

I suspect you're thinking of the saying "if you have to ask the price, you can't afford it", but that doesn't apply here (and anyway, it's a non-sequiteur so a rather silly saying).

So please, enlighten me, what is the point in anything anyone here does (in their various audio/musical roles) if at the end of it what it affects is something that is not audible to humans?

(Note I'm not arguing what is and what is not audible to humans, just that at the end of it all, it has to be audible to matter)

Quote:
What's to say that any such limitations exist at all? Why would you take such a presumptuous position, when it could mean that all of your "groping about in the darkness", so to speak, is entirely misguided?
Hmmm, the physiology of the ear, the laws of physics, oh and actual testing.

There's nothing presumptuous about it, it's common sense, backed up by real world data, human beings have limits to all their senses.

Quote:
The truth about sound, or anything, really, is not something to hunt down so that you can put it in a cage for the purpose of "ascertaining its limitations". That's not a very enlightened approach to gaining knowledge.
Put it in a cage? What on earth are you talking about?

You gain knowledge by asking questions and finding the answers, which is what testing is all about.
Old 16th March 2012
  #345
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Quote:
Originally Posted by dcollins View Post
It might help to think of Laarsø as the entropy generator of this forum.

I do.


DC
With a missing keyboard key rather than a bit or two.
We'll send Andy replacement keys.



Keep it civil gents
Old 16th March 2012
  #346
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Quote:
Originally Posted by j_j View Post
This does work for lousy loudspeakers, it's not the same as the real thing at all, but first you have to have the original bass frequencies in order to do this. If somebody has removed them already ...
Well, yes.
But the idea is to compensate from the original PCM, not after lossy conversion.

--------------------------

Maybe I have not explained well the concept of "lossy audio compensation."
The idea is to have two different masters when needed:
1. To have a PCM master (24/96) for lossless distribution.
2. To have a "lossy compensated" PCM master (24/44.1) for lossy distribution.

If lossy compensation is not too aggressive or not necessary only one master will be OK.

I think, at least in modern pop-rock music, it will be necessary the two masters: for lossless and for lossy.


Old 16th March 2012
  #347
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Quote:
Originally Posted by Laarsø View Post
Seriously, the only reason lossy media beats CD is convenience and impulse click-buys.
Absolutely!
That's the idea behind lossy audio.

Quote:
Originally Posted by Laarsø View Post
Actually, it doesn't look so sexy at that speed. As Dan Lavry points out, the low end loses accuracy starting at sampling rates above ~55 kHz Fs due to the need for settling between pulses. So, slow down your Mustang, Sally.
I don't agree.
Have you tested the 69 MHz experience...

69 année erotique.avi - YouTube

Old 16th March 2012
  #348
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Move along gents, Nothing to see here....
Old 16th March 2012
  #349
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Quote:
Originally Posted by Kees de Visser View Post
Perhaps JJ can explain what he considers a listening test and how it's different from the Hydrogenaudio standpoint.
I was somehow under the impression they were not that different.
Including positive and negative controls, lots of training for the test as well as familiarity with the equipment and music, and equiment validation are the biggies.

Test evaluation might be an issue, too. Many tests, including some of the MPEG tests and 1116 make assumptions that the entire population reacts the same to impairments. While basic masking is universal, what people dislike when they can hear something is NOT universal.
Old 16th March 2012
  #350
j_j
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Quote:
Originally Posted by Laarsø View Post
I agree that it's a "false example of professional defamation."
Once again, retract your false, defamatory statement promptly. I will have no futher business with you until your abject, total capitulation in this matter.
Old 16th March 2012
  #351
j_j
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Quote:
Originally Posted by Jon Hodgson View Post
Put it in a cage? What on earth are you talking about?

You gain knowledge by asking questions and finding the answers, which is what testing is all about.
It is typical of some audio "experts" and would-be "experts" to reject science, that being what you just alluded to up there, science as the practice of making a hypothesis, and TESTING it, and then examining what really, actually, by damn happened when you ran the test. It's about externally verifiable, falsifiable, testable, and repeatable results, not about the dogma of various belief systems or anecdotes based on wishful thinking.

Science is all about what actually happens, not about anecdotal guesswork, perverse belief systems (be they in the presumed paranormal ability of the human ear or in the presumed superiority of linear system paramaters). Both the "golden ear" believers and the SNR weenies are practicing a kind of religion, the first unwilling to even test what they submit the truth to be and requiring faith, and the second unwilling to take any step beyond their mathematical tests again stating issues as a matter of faith, choosing to accept as dogma that the ear is a linear system (you hear laughing on that front going all the way back past Helmholtz). (I find it almost amusing in this day and age that people still try to hear with their eyes, looking at a time waveform, when the ear takes that apart as a first function of the basilar and tectoral membranes.)

Both kinds of people, as we have seen in this thread, are willing to slander, libel, otherwise defame, and deliberately, with obvious malice aforethought, attempt to subvert actual discussion of what actually happens in the real world. In this, they are an audio cognate of the young earth creationist, appealing to emotion because they know they have no material fact to back up their assertions. They can brook no discussion of fact, and will deliberately engage in knowingly dishonest defamation in order to derail discussion. Such actions show the utter lack of ethics, morals, and knowlege of such ignoramii.

Unfortunately for all of us, while Young Earth Creationists are not accepted in the geology community, the paranormalists and the SNR weenies are large, noisy, dishonest, and influential part of the audio community.
Old 16th March 2012
  #352
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Quote:
Originally Posted by optimax4000 View Post
What's to say that any such limitations exist at all? Why would you take such a presumptuous position, when it could mean that all of your "groping about in the darkness", so to speak, is entirely misguided?

The truth about sound, or anything, really, is not something to hunt down so that you can put it in a cage for the purpose of "ascertaining its limitations". That's not a very enlightened approach to gaining knowledge.

Indeed, if anything suffers from "limitations", it is the methods some people employ.
You're either high, in college, or both.

Air molecules impose a limitation on sound. For example, we know there is a maximum possible volume before the air simply can't deform any farther to create a larger magnitude pressure wave.

Technology imposes a limit on our ability to recreate the sound that has a natural limit of it's own.

Biology imposes a limit on our ability to hear the recording of limited natural sound created by limited technology.

Either learn the limitations or be baffled when you run into a wall.
Old 16th March 2012
  #353
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Quote:
Originally Posted by Cheebs Goat View Post
You're either high, in college, or both.

Air molecules impose a limitation on sound. For example, we know there is a maximum possible volume before the air simply can't deform any farther to create a larger magnitude pressure wave.

Technology imposes a limit on our ability to recreate the sound that has a natural limit of it's own.

Biology imposes a limit on our ability to hear the recording of limited natural sound created by limited technology.

Either learn the limitations or be baffled when you run into a wall.
There is no upper limit to sound pressure. Air may become highly nonlinear, but you can always go 'one louder.'

How loud was The Big Bang, for instance? You would definitely need a pad for that one.


DC
Old 17th March 2012
  #354
j_j
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Quote:
Originally Posted by dcollins View Post
There is no upper limit to sound pressure. Air may become highly nonlinear, but you can always go 'one louder.'

How loud was The Big Bang, for instance? You would definitely need a pad for that one.


DC
This is true, however, our ears are able to deal with about 2*10^-10 Atmospheres to about 10^-5 atmospheres of dynamic range. That's from 0dB SPL to about 94dB SPL, FYI.

Above about 120 dB SPL air becomes noticably nonlinear. Above 140dB SPL you can kinda pitch the idea of a linear transmission out the window. Above 170dB is in the "military" range.

Another thing to realize is that due to the molecular nature of air, the eardrums have about a 6dB SPL white noise imposed on them in the 20-20K range, simply due to the individual molecules bouncing off the ear drum. This sets a lower limit to perception in any ERB (you know, the mechanical filter bandwidth in the ear that some people here seem to forget about) that is lower than 6dB SPL, but in the most sensitive range gets down to about -15dB SPL, which is JUST below the threshold of hearing.

So, it's reasonable to say that the ear can very nearly hear the brownian noise at the eardrum.

Ears are sensitive. Loud is not much of an atmosphere. A big thundercloud going over can give you a 10% change in air pressure, that's 174dB SPL, of course in the milliHz to microHz range, which just doesn't register, thanks to the highpass filter built (fortunately) into our middle ear and eardrum.

ETA: If it were possible (i.e. if air were linear), a 194dB SPL level would be 1 atmosphere RMS. Hard to achieve, though, in fact impossible, since all of the linear media equations fall splat at that kind of pressure change.
Old 17th March 2012
  #355
j_j
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Quote:
Originally Posted by optimax4000 View Post
The truth about sound, or anything, really, is not something to hunt down so that you can put it in a cage for the purpose of "ascertaining its limitations".
No, that's the gospel and dogma of the luddite anti-scientific sound engineer, not the truth.

I can easily show the existance of a minimum sound pressure level at your eardrum. That's not supposition, it's testable, measurable, and repeatable. I can easily show you sound becoming nonlinear at high levels, and at high frequencies. I can show how much attenuation one gets from a sound emitted on the stage, 100 feet away, as a function of frequency (hint, it's not to be ignored!). I can show you the lowest levels that a completely undamaged human auditory system can capture. I can show you the masking levels inside an ERB.

In short, there is a lot of knowlege out there, testable, verifiable, incontrovertable knowlege, knowlege that you have ignored and wish to insist does not exist.
Old 17th March 2012
  #356
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Quote:
Originally Posted by dcollins View Post
There is no upper limit to sound pressure. Air may become highly nonlinear, but you can always go 'one louder.'

How loud was The Big Bang, for instance? You would definitely need a pad for that one.


DC
http://wordpress.mrreid.org/2011/01/...loudest-sound/
Old 17th March 2012
  #357
j_j
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Quote:
Originally Posted by Cheebs Goat View Post
Somebody needs to tell them that they are dead-flat-outright-wrong.

Sorry. They're wrong. Period. You can only go to near zero pressure, but you can go way, way over 1 atmosphere overpressure. Just ask anyone 10 feet from where a shell from the Iowa lands.

They're also assuming that dB and SPL make any sense at that level. They don't do that either.
Old 17th March 2012
  #358
j_j
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Quote:
Originally Posted by optimax4000 View Post
That's kind of a vague statement, Jim, but, to the extent it is meant to apply to this discussion, and / or to me, I think it is erroneous.
Well, how the ear works is quite well understood. What it sends down the auditory nerve to the brain is pretty well understood, too, so in fact there is a whole lot of testable, verifiable information out there.

Sorry you disagree, it doesn't change the facts of the matter.

In particular (given you "optimax" title) I dare say that how loudness works is, despite 1770/1, quite well understood. Density is nothing more than loudness enhancement. I won't go into clipping the S channel
Old 17th March 2012
  #359
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Quote:
Originally Posted by optimax4000 View Post
I was referring to the saying "If you have to ask, then you wouldn't understand".
Try me
Quote:
Here we disagree, I believe.
Well perhaps you think there is some sort of karmic benefit to doing stuff to audio that nobody ever hears, if it makes you feel good doing it, then that's cool for you... but if you think it makes a difference to the guy sitting in front of his hifi, then yes we do disagree.

This isn't so much "if a tree falls in a forest and there's nobody there to hear it, does it make a sound?" as "If there's a difference in a signal shape, and nobody capable of hearing it, who gives a ....?"

i'm talking about what makes it to the listener, discussions and arguments about things that are inaudible at one point in the process but have audible effects further down the line are a seperate issue, I'm saying that what matters if what is audible at the end of the line.
Quote:
There are any number of ways of gaining knowledge. "Testing" is certainly not the only way, nor the best way. It is even arguable that it is no way at all.
I never said testing was the only way to gain knowledge, though it is possibly the only answer some questions, and certainly the best way in many circumstances.

But I'd love to see the argument that it's no way at all.

You do understand that the scientific method, including testing, is one of the essential elements that gave mankind the knowledge for us to be having this online conversation don't you?

So, please explain how it is arguabe that testing is "no way at all" to gain knowledge.
Old 17th March 2012
  #360
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Quote:
Originally Posted by optimax4000 View Post
Mmm Hmm, and "staying down from max a tiny bit" is SOP already. -.3dBfs is kind of "standard".

The Apple document seems to be just some sort of attempt at promo material for them. They aren't saying anything new. In fact they seem to be trying to take credit that's not even due them.

Worse yet, they purport to be instructing us on how to achieve "hi-fi", when what they do [unnecessarily, btw] is the opposite of that.

Nobody is going to "Master for iTunes". That's silly, imo.
finally...it took 10 pages for someone else to see this too?

JJ think see are arguing with his expertise...when all we are doing is saying that unfortunately when it comes to AAC...it isn't important because the format stinks.



Quote:
Originally Posted by Ben F View Post
Move along gents, Nothing to see here....
Actually this is super important.

Quote:
Originally Posted by optimax4000 View Post
As they say, "If you have to ask ............".




What's to say that any such limitations exist at all? Why would you take such a presumptuous position, when it could mean that all of your "groping about in the darkness", so to speak, is entirely misguided?

The truth about sound, or anything, really, is not something to hunt down so that you can put it in a cage for the purpose of "ascertaining its limitations". That's not a very enlightened approach to gaining knowledge.

Indeed, if anything suffers from "limitations", it is the methods some people employ.

JJ seem quite well versed within the confines of his own imagination...

however he seems to be imagining that some "magical AAC encoder" exists that doesn't change the resultant audio.
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