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MQA Deep Dive - I published music on tidal to test MQA

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muslhead

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I obviously meant a purpose to the consumer, not to our MQA overlords :facepalm:;)
I know, since i am not smart enough to contribute technically to this thread i thought the least i could do would be to toss some fuel on the flame :)
 

RichB

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Although you say that have no interest in giving what I write credence, if you are really interested in learning, I will try again.



You're correct that others share your misunderstanding, typified by your earlier comment that "it's even more deeply insulting and disrespectful to respond in turn with something to the effect of, 'I did not say 13 bits is enough; I only noted that in a recording like the one I mentioned in my comment, 12-13 bits was sufficient in the spectrum below 2kHz.'"

I don't understand why it is insulting to offer further clarification. But even if you feel insulted, here goes:

The 24-bit recording of room tone had a spectrum that had an amplitude close to the 13-bit level in the very low bass. However, the specturm sloped down as the frequency increased and In the treble the amplitude of the noise was closer to the 18-bit level. That does not mean, as you falsely claim me as saying, that "MQA-style encoding doesn't impact the resolution of the recording because 'real world' recordings don't need more than 12-13 bits to fully capture them." I haven't made any comment on MQA.

The music recordings I made in the church where I recorded the room tone peaked just below 0dBFS. As it is not possible to record the music without the analog noise, and not feasible to record frequency bands individually, a recording of that music will need to be made with a resolution of at least 18 bits, if information is not to be lost.

18 bits, not 13 bits.

And as I explained, the spectra statistics of the analog noise floor allow a hidden data channel to be inserted in that analog noise floor. And as long as the spectrum of the data embedded in that channel is encrypted as pseudo-random noise, has the same spectral statistics as the noise floor in the recording, and has an amplitude sufficiently below the noise floor at all frequencies, there will be no loss of bits/information/resolution.

Noise is noise.



I look forward to you doing so.

John Atkinson
Technical Editor, Stereophile

We finally get an answer.
When first discussing this, I asked for clarification on > 16 bits, there was no response. So, 18 bits is the answer.
MQA may just fall 1 bit short from capturing your recording. Perhaps, this explains the silence.
However, 96kHz/18 bit file would be fine.

There are DACs capable of resolving 20 bits, perhaps you have measured these, silly buggers, what where they thinking making such products.

- Rich
 
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Tks

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Anyone get to addressing why muddling around with lossy 13, 14, 15, 16, 17, 19, 20, or 21-bit MQA files are relevant when you can opt for 24 bit lossless? Especially seeing as how no appreciable storage savings are to be had with MQA in the first place?
 

Raindog123

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Anyone get to addressing why muddling around with lossy 13, 14, 15, 16, 17, 19, 20, or 21-bit MQA files are relevant when you can opt for 24 bit lossless? Especially seeing as how no appreciable storage savings are to be had with MQA in the first place?


You? With that silly question, again!? And what, next you’ll ask why does one need ultrasonics!?
 
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RichB

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Unfortunately I think we are seeing this chilling effect right before our eyes. Maybe a little compassion is in order though. People need to make a living and taking on internet monopolies is a good way to get cancelled. The bigger problem is that some day any one of us may find ourselves in a similar situation.

Not everyone gives tacit support to something they know is wrong and unfair.

I try to explain to my children (with little effect thus far) to look for the deeper truth, that sometimes support for issues look good/innocuous may actually harm people. Then, I go on the teach them the meaning of the word "innocuous" :)
With kids, you are playing the long game.

- Rich
 

RichB

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Apparently annoying you, for one thing, mansr :)

John Atkinson
Technical Editor, Stereophile

Perhaps for a deposition, volunteer nothing to the other side :)

- Rich
 
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GoldenOne

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@Archimago and @GoldenOne do you agree to the above?

Regarding patents. Here is an interesting read
Wavelet (= "origami") compression of audio signals
http://profesores.elo.utfsm.cl/~mzanartu/Documents/Wavelets Project.pdf

From 2005 based on articles from 1993 and 1998
B-splines are a special kind of wavelets (used in MQA)
Article from 1993
https://ieeexplore.ieee.org/document/258086

BTW: A very smart person here where I live have found these. (not me)
I am an amateur yes.
I want to be VERY clear. I am not an engineer. I am currently doing Economics at university. Audio and engineering are just hobbies of mine. I have a fair bit of experience but in no way am I a professional or expert. And I do not claim to be.

But you do not need to be an engineer to test things.
If a manufacturer says a car will do 0-60 in 5 sec, you don't have to know the intricacies of designing an engine to take it for a spin yourself and test that claim.

You don't need to know the intricacies of signal processing theory overall in order to test if something is or is not lossless.

This video/post wasn't made to try to make myself look clever. It was done because no one had done testing by actually getting files encoded in MQA and so I thought it would bring about some new/useful information.
These tests are not perfect. But perfect tests cannot be done because MQA prevents it. Because THEY do not allow proper testing to be done.
Not because myself, archimago or anyone else is just not smart enough to form perfect tests.
Some of the criticisms such as that if I'd abided by MQA's 'triangle' diagram it would have worked I also DID attempt to test but as mentioned they nuked the tracks before making it to Tidal.
They could have been open, they could have been honest. But their hostile censorship approach meant that they may have shot themselves in the foot by not allowing that track to be tested. So quite honestly it's their own fault.

I have said both publicly and to MQA directly that I would be very eager to work with them to conduct testing that is agreeable to both them and myself. That remains true. I have no grudge or vendetta against MQA. I just want the truth. And right now all evidence suggests that MQA's marketing claims and what they are selling people is not true. If evidence to the contrary is presented that would be great and I would be quite happy to openly say I was completely wrong.
And if it were needed I'd be happy to sign an NDA or something in order to conduct testing with whatever the confidential tools MQA has are, and give a public 'vouch' as such that their claims are true without disclosing anything 'secret' (if the testing conducted did show that were the case). But honestly I really don't think that would be necessary nor a good way to go about it.

My issue is that there is no transparency. And in this hobby, when something claims a benefit with absolutely no evidence for that, we typically call it snake oil. I don't see why MQA is any different other than it has some more well known names attached.

I really do not understand why so many people react so angrily to any testing done on MQA with all sorts of criticisms that the tests are imperfect when it is MQA that is preventing proper testing from being done, not those doing the testing.
Why are people so happy to simply take MQA at their word and trust them when there is so much evidence from various people showing all sorts of issues and contradicting MQA's claims?

How much evidence does there need to be before it is fair to say that MQA should probably step up and provide some evidence now.....
Why are they given a free pass to sell (or force) a product on people with nothing backing it up when something like telos is not? https://telos-audio.com.tw/quantum-noise-resonator/ (seriously look through this website it's hilarious)

The arguments about credentials, subjective preference and manufacturers supporting it are all nothing to do with the issue I intended to further discussion on, which is simply, are MQA's marketing claims true?
 

RichB

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Jisus man, how many times do we have to repeat the same? Those "repeatable"measurements are measuring the wrong things:

1- square waves, high amplitude white noise, and presumably big amplitude impulse tones completely outside the maximum amplitudes of the music the system is programmed for, as all of them contain upper octaves and ultrasonic in high amplitudes. MQA is not intended to register high amplitude in ultrasonics, because there is NO MUSIC with that profile, and because that space is better used for custom filters fixing time domain issues. If you understand what MQA does (and if both accomplished amateurs are in fact accomplished, they knew it BEFORE doing those tests), you don't need a test to know a square wave will not perform OK.

2- A bit perfect match that by definition is impossible, as MQA replaces those below the noise floor with dithered information. Again, what an accomplished MQA reviewers should know in advance.

3- To make things worse, MQA assumes the noise band is dithered; these tests omitted that basic step, and so, the algorithm is fed with wrong information. It is obvious the multitude of anomalities would occur doing that.

4- Even if all of the above were not an issue, even then you wouldn't get that pretended bit-perfect match, because the system is intended to be lossless compared with analog input; but to fix the flaws of that input (by correcting time domain issues) if instead that input is digital.

5- If MQA were performing as bad as their conclusions say, the plots above ( that even then are incomplete, since they are comparing a 352K input with a 88.2 Khz output, leaving information the system has registered unprocessed) wouldn't have the degree of coincidence they have. Then... something must be wrong with those tests, don't you think?

What you are questioning is the very definition of the MQA design (noise shaping, encapsulation of data in noise bands, limited amplitude in high frequencies, deblurring of time domain information, etc), because all of that differs with your immaculate conception of how perfect a simple Redbook file is. If so, you don't need to backup your criticism in test trying to demonstrate the things the system is not intended to do.

By George, I think you've go it! :)

I am questioning all of MQA marketing claims, the overly complex engineering, the reduction of dynamic range, the loss of original data, the royalty scheme to extract money from producers and vendors and give to one of the richest men in the world.

Once you understand that MQA is intended to insert itself into the music eco system for profit and serves no other purpose, you can realize the its design, what some call elegant, is actually something that would make Rube Goldberg proud.
Excessively complex with NO benefit to the consumer.

You are really missing the goal of MQA, for some reason, you think it resembles their marketing pitch.

- Rich
 

mansr

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I am an amateur yes.
I want to be VERY clear. I am not an engineer. I am currently doing Economics at university. Audio and engineering are just hobbies of mine. I have a fair bit of experience but in no way am I a professional or expert. And I do not claim to be.
It doesn't matter who or what you are. You managed to do something nobody has done before: put some test signals through an MQA encoder. Moreover, you have succeeded, where more technical arguments did not, in convincing a number of people that MQA is nothing but a sham. For this, we owe you our gratitude.
 
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GoldenOne

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I think you will find that the answers you are looking for are to be found within your chosen field of inquiry, the only engineering at play is of the social variety. Why do these "luminaries" defend MQA? Could it be economics?
Of course. Money makes the world go round and it's no different here.

To be honest if the public evidence wasn't enough the conversations that I (and likely others, I know Chris Connaker has had some interesting convos) have had with manufacturers regarding MQA should probably say all that needs to be said.

There are a few manufacturers who are quite happy with the deal they're getting. As some of them have what is effectively a 'mutual growth' agreement. They get to add MQA for free, more people buy their products, and MQA gets more market presence.

But MOST manufacturers, especially higher end ones and those who are doing proprietary designs, absolutely hate it. And only implement it because they are effectively being forced to by consumer demand.
Not only is it frustrating for them because some have to pay quite honestly absurd amounts for licensing of MQA, but also because in many cases it means that they have to disclose proprietary/confidential aspects of their design, and in some cases change it according to MQA's requests. They literally lose control over the design of their own product.



But also, if people think that assuming MQA continues growing, that they will operate in the same way they do now in 2-5 years time, they're fooling themselves.
Once a company has a monopoly on something, they can charge whatever they like. And make whatever demands of manufacturers they like.
A fair few manufacturers get free MQA licensing at the moment, but if MQA becomes the "standard" in the hifi market, then they sure as hell won't be cutting manufacturers any discounts then. And you, the consumer, will have to pay for it.

Look at what happened with dolby. There is absolutely no room for innovation in that market because dolby has a monopoly.

This is not good for manufacturers, it is not good for consumers, it is not good for anyone but the company holding a monopoly.


If MQA had a genuinely worthwhile product they should demonstrate that and allow the demand for it to drive itself. None of this waffly marketing, black box obscurity and hostile response to third party testing.

Competition drives innovation. I can't understand why so many people are happy to throw that away and many of them WANT this one company to have complete integration in this entire market.
 

restorer-john

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It doesn't matter who or what you are. You managed to do something nobody has done before: put some test signals through an MQA encoder. Moreover, you have succeeded, where more technical arguments did not, in convincing a number of people that MQA is nothing but a sham. For this, we owe you our gratitude.

Very well said. I vote @GoldenOne "ASR member of the month" :)
 

PierreV

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Pseudoscientists can be annoying, indeed.

That's OK. His recondite arguments and his tasteful dance around the real issues help support the idea that there is indeed a secret society conspiring in favor of MQA. Whether there actually is or isn't is irrelevant in terms of entertainment value. And it keeps us occupied while we still wait for a clear and concise explanation of the benefits of MQA for customers.
 

muslhead

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That's OK. His recondite arguments and his tasteful dance around the real issues help support the idea that there is indeed a secret society conspiring in favor of MQA. Whether there actually is or isn't is irrelevant in terms of entertainment value. And it keeps us occupied while we still wait for a clear and concise explanation of the benefits of MQA for customers.
There may be one other explanation. Maybe, just maybe Mr JA is under NDA. He seems to know a lot but stops just before spilling the beans, teasing readers and leaving them wanting for more. I don't know how often that comes about in his position but if i were a mfg with what i consider to be proprietary design or information (and that info was needed to explain more about my product to a prominent reviewer) an NDA would be one of the first things i would put in place.

Not a lawyer and dont play one on TV but my interpretation is Mr A knows a lot more than he is or can say. If so, you sort of have to give him a get out of jail free card, no?
 
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