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

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Let us reduce this to simple terms.
As it stands, without MQA, we have CD quality audio.
We have Hi-Res audio, from master recordings that we assume is as the original artist intended.

With MQA we have people telling us that it improves upon the original by some mysterious method which cannot be proven and has been shown to be not so.

HOWEVER

MQA was created by "luminaries". We should bow down and accept MQA.

The plane for Guyana is leaving next week. All the MQA followers are expected to be there.
 

Rottmannash

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Except that if some are adding $30 for MQA supports, it would mean in this case it's $30 for adding MQA and $140 in pure benefits for Matrix.
In this case, I won't defend the manufacturer ;)


Right, what I wanted to highlight is that Amazon cost can be his own operating cost, while Tidal is paying them more for the same bandwidth.



Are you sure this Hiby is a full decoding+rendering DAC and not just a rendering one ?
They may exist but which DAC is doing MQA decoding+rendering and is not using Blue or Green ?
The last DAC I got can process MQA and has Blue or Green light when it's doing all processing, and Magenta only if decoding is done before (like by Roon or Tidal app, if I set it to do that).
So I thought that Magenta was always linked to the rendering only, once decoding is done.

We can rely on manufacturer presentation, they are a lot mixing terms like decoding and rendering the way they like it, and there are already using while their DAC is only rendering (I think a iFi is in this case)

On a side note, I just watched the youtube video from Helm regarding the Helm Bolt MQA :
It's insane, it looks like a MQA advertising more than a Helm Bolt one :
- affirms a better quality in MQA than in PCM
- "unfolds MQA stream back into the same quality as the originally mix" No, it can come from the original mix, it doesn't mean it's the same.

In the end, MQA themselves are making nicer than it is, but some manufacturer too
I'm not saying it's really bad either, just that they are lying on some points, and there's no authority to make them change that.
My Hiby R5 fully unfolds MQA streams.
 

DDF

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Forget the “3 bits” that people are mentioning. It’s a red herring (or maybe the sound of axes grinding).
I think the argument is simple and we're speaking at cross purposes.

You're assuming the bottom bits don't really exist as they're noise and can be repurposed for ultrasonic information that can't possibly be heard, in concert with a "deblurring" process that could be implemented with all pass filtering without otherwise tossing bits.

The rest of us are understandably upset that instead of just offering this as an alternative it replaces and adulterates the true full on lossless files, especially the 16 bit files. To call this "axe grinding" is a bizarre assertion from someone that spent their life in the pursuit of the highest quality audio.
 
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RichB

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Thank you!. iPhone translator helps sometimes... :)

Because it is a very interesting thing they are doing, and it is a shame that people trash it just because they are told this could be worse (without even hearing it!), just because reading these absurdities of lossyness, 13bits, bad rendered square waves, etc. Also because I think this encapsulation is a way to make a healthy music industry, allowing them to deliver the best possible quality and still have their assets protected, and I really, really love music; because with a tenth of the money I used to spend in music, I can now have an almost infinite library of even better quality (with Tidal, I hope that also with others soon); but most of all... because when rendered by hardware it sounds so freakingly good that sometimes (not always, of course) it is almost unbelievable.
Yes, some are bothered by facts and find MQA inc. unbelievable. :)
Enriching Mr. Dorsey is not the right direction. Direct distribution that supports the artist is a more noble goal.

If only there we had HDR-Audio (High-Dynamic Range) that would be an audible improvement instead of this drivel.
We should be looking to expand dynamic range not consume it chasing inaudible frequencies and ephemeral blur.

- Rich
 
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Because in ultrasonic band the content of music (just harmonics of increasingly lower magnitude) is NOT 24 bit deep, but as Atkinson's post says, 5 bits, and decreasing even more the higher you move in frequency. The rest is noise below, and empty bits above. And so, they don't need to pack 24 bits below the noise of the first 24Khz band, but instead much, much less (and btw, this is not a mysterious, hidden information; it is explained by MQA in their documents even with annoying detail).

Unless, of course, your signal is white noise of big amplitude or square wave, that instead DOES have very high amplitudes of harmonics in ultrasonic (and also in the high region of the sonic bandwidth). Which, btw, is the reason why Amir tests of DACs increase the band to ultrasonics when measuring square waves. That's why MQA performs bad with that type of signal: it is not intended to process that. One of the many reasons why these tests are flawed.

Btw, I can't figure out what's worse: if Archimago and GoldenEar didn't know that (almost unbelievable); or that they knew it and even then, they prepared a test file knowing the type of failures they would get.
Other than via PowerPoint Engineering, seen to much of that from MQA, or technical statements expressed only in words in this forum, can you please provide links to any technical analysis that demonstrates and verify your claims that you know of?

Thanks.
 
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*** Yikes! This post is being interrupted because I just noticed I had NeutronMP set with 4x oversampling and I expect this is why the sampling rates where so high. I’ll double check everything and update as required. Your regular post will resume shortly with no thanks to this user’s stupidity though. ***

@@@ We are now returning your to your regular post. I have found that only the MQA-CD file’s sampling rate was effected. I’ve updated the screen shot but to summarise: the unfolded MQA-CD is now showing as a 24bit/44.1kHz. That means that other than changing the bit depth from 16 to 24 no other changes have been made. The more I see of MQA the more it appears to be nothing more than a fancy shell game. @@@

Ok I’m sure everyone knows this already but just in case some don’t.

Did you know NeutronMP appears to have reverse engineered the full unfolding of MQA FLAC and MQA CD files?

Using one of the downloadable 2L tracks: Hoff Innocence

386F4F29-07A0-4788-BAFB-28FFF501F1D6.jpeg


Exhibit A (MQA-CD):

7C2836B4-FDD1-4694-8226-C0730C925975.png


What NeutronMP sees the raw file as:

8702F424-C1EB-43DE-A2AC-92C163745C59.jpeg


What the (Non MQA) DAC sees (Image updated with correct sample rate — the idiot responsible for the initial debacle has been shot):

D67A2647-4171-469B-BB3C-B4CAD882BCB2.jpeg


Exhibit B (MQA Original Resolution):

DED085AE-FDC8-429D-B76A-85EE2B8F4AF4.png


What NeutronMP sees the file as:

E00D0EB7-C372-4FBA-861D-8C78B01FD5F5.jpeg


What the DAC sees:

3C96D914-AE9B-4D31-9982-B29F0EF7C7F9.jpeg


Sorry to bore you all with all this but…
 

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JEntwistle

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Ok I’m sure everyone knows this already but just in case some don’t.

Did you know NeutronMP appears to have reverse engineered the full unfolding of MQA FLAC and MQA CD files?

Using one of the downloadable 2L tracks: Hoff Innocence

View attachment 126537

Exhibit A (MQA-CD):

View attachment 126538

What NeutronMP sees the raw file as:

View attachment 126539

What the (Non MQA) DAC sees:

View attachment 126540

Exhibit B (MQA Original Resolution):

View attachment 126541

What NeutronMP sees the file as:

View attachment 126546

What the DAC sees:

View attachment 126545

Sorry to bore you all with all this but…
Is this actually analyzing the data in the file, or is it reading metadata (sorry for my ignorance on this topic)?
 
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Is this actually analyzing the data in the file, or is it reading metadata (sorry for my ignorance on this topic)?
NeutronMP plays the file to the DAC fully unfolded. No MQA DAC required. In fact if I try an MQA enabled DAC it will only play as PCM.

So, yes, it’s analysing the data and decoding it.

Something I thought was impossible for software to do without a fully compliant MQA DAC.

Therefore MQA could provide full decoding to the Tidal App in software, not just the first unfold but then they wouldn’t get those juicy licensing fees from the DAC manufactures.

The more we dig into MQA the more it stinks.
 

ebslo

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Forget the “3 bits” that people are mentioning. It’s a red herring (or maybe the sound of axes grinding). I already described in message https://www.audiosciencereview.com/...-music-on-tidal-to-test-mqa.22549/post-759747 how, with a digital audio recording of actual music, it is possible to create a hidden data channel in the least significant bits without losing resolution or “bits.” So forget about MQA for now and consider the following thought experiment (which has nothing to do with “deblurring,” “leaky” reconstruction filters, B-splines, etc):

Imagine that I have a 24-bit audio file of the music from which I extracted that room tone recording mentioned earlier, sampled at 2Fs (88.2kHz). I would like to create a version of that file that will play with a baseband sample rate (44.1kHz) in systems with antique D/A converters but also play at the original 88.2kHz sample rate in my big rig.

I take that 24-bit file and using a complementary pair of low- and high-pass digital filters, I split it into two 24-bit files: one containing content below 22.05kHz so that it can now be considered as having an effective sample rate of 44.1kHz; the other containing content from 22.05kHz to 44.1kHz. As long as the filters used are of a specific type, the band splitting will be transparent.

I examine the spectrum of the background analog noise in the baseband file and calculate that I can create a hidden data channel in the 5 LSBs (bits 19-24), which are 2 bits (12dB) below the lowest amplitude of the audio data. I then examine the spectrum of the 2Fs file. I find that, as expected, the ultrasonic content both has a self-similar spectrum that declines in amplitude with increasing frequency and is at a low level. The level is so low, in fact, that the actual quantization is close to 5 bits.

So, if I encrypt the 5-bit/2Fs data as pseudorandom noise with a spectrum identical to the background noise in the baseband file, I can bury those data in the hidden 5-bit data channel. I now have a single 24-bit file sampled at 44.1kHz that will playback with the same audio quality as the original file (other than the low-pass filtering at 22.05kHz).

For playback in the big rig, a flag that I have embedded in the file’s metadata tells the D/A processor that it has to extract and de-encrypt the 5-bit audio data in the hidden channel. It then upsamples those data to 2Fs, attenuates the data to the level in the original file – this pushes the 5-bit quantization noise below the original background noise floor – and adds the result to the baseband file that has also been upsampled to 2Fs.

In theory, I am playing back the 24-bit baseband file as if it were a 2Fs file with no loss of bandwidth or information or resolution or “bits.” (That would be the “thought experiment” equivalent of the “MQA Stereo original resolution” files in the 2L screenshot you included in your post.)

The devil, of course, lies in the details. How do I encrypt the low-bit-rate content between 22.05kHz and 44.1kHz so it resembles pseudorandom noise? I have no idea, even though I had discussions with the late Michael Gerzon about this back in the day. What if the starting point is a 16-bit file, where there is much less information space in which to embed a hidden data channel beneath the analog noise floor? (That is the “thought experiment” equivalent of the “MQA-CD” files in your 2L screenshot.) Again, I don’t know. What if the statistics of the original audio don’t conform with the self-similar spectrum that I am expecting? That, of course, is how GoldenOne “broke” the encoder.

But again, to talk about “losing 3 bits” or “truncating” the audio data is incorrect.

John Atkinson
Technical Editor, Stereophile
First, thanks for the detailed description, this is one of the best explanations I've yet come across. However, it appears in direct conflict with your opening and closing statements. The information in those bits was either kept or it was lost, and your explanation shows it was not kept. The claim that there was probably nothing of interest in those bits, regardless of its merit, does not change that.
 

scott wurcer

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How do I encrypt the low-bit-rate content between 22.05kHz and 44.1kHz so it resembles pseudorandom noise?
The ADSL folks figured out how to encode all the data as pseudorandom noise. 64QUAM, 256QUAM works through razor wire, probes stuck in mud or potatoes. These schemes are everywhere in the internet infrastructure.
 
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NeutronMP plays the file to the DAC fully unfolded. No MQA DAC required. In fact if I try an MQA enabled DAC it will only play as PCM.

So, yes, it’s analysing the data and decoding it.

Something I thought was impossible for software to do without a fully compliant MQA DAC.

Therefore MQA could provide full decoding to the Tidal App in software, not just the first unfold but then they wouldn’t get those juicy licensing fees from the DAC manufactures.

The more we dig into MQA the more it stinks.
No comforting blue light and the friendly green light. That's BS.

No way NeutronMP supports MQA
 
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No comforting blue light and the friendly green light. That's BS.

No way NeutronMP supports MQA
Yes way it does.

Sorry, only the lights or display that your DAC that uses to indicate the PCM sample rate your DAC is receiving (if any).

But you could just by a blue LED, resistor and just wire them to a battery through a switch.

Hey! Maybe MQA could build these for those that have developed an MQA coloured light dependency.
 
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As a bystander…
All I’m reading is theoretical jargon and flowery marketing terms from de-facto mqa supporters in this thread. 74 pages in and I still haven’t found a described benefit that’s not either vague or has been totally debunked.
MQA provides calming coloured LED lightning. What more do you want?
 

JSmith

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In this country it fits neatly into a breach of Australian Consumer Law as the goods are "not as described".
Yeah I raised that here earlier in the thread.

Here are two of the responses I received about the UK laws;
As I understand it, the UK and many other jurisdictions infer an initial category of permissible exaggeration, to the extent reasonably to be expected from advertising. I think because of David Ogilvy's slogan from the early 60s: "At 60 mph, the loudest sound in the new Rolls Royce is the ticking of the clock." Which was patently absurd, but judged to be harmless in intent. Like "Perfect Sound Forever", which was taken to mean "Better than LP quality and doesn't scratch so easily." This "no harm no foul" category makes legal attacks difficult, especially if complex or pedantic.


JSmith
 

acbarn

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As a bystander…
All I’m reading is theoretical jargon and flowery marketing terms from de-facto mqa supporters in this thread. 74 pages in and I still haven’t found a described benefit that’s not either vague or has been totally debunked.
That’s all they’ve got.
 
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Well, the cost is given as 0.07 bit of DR per MQA's answers to Stereophile, provided you have a MQA decoder.
https://www.stereophile.com/content/mqa-questions-and-answers-bit-depth-mqa
That is a statement that, per the usual constraints, can't be verified anyway.
No mention of the DR loss on standard CDs, but @mansr 's estimate seems to be accurate (as a best case).

I don't think anyone disputes that you can cleverly repurpose bits in a 96kHz 24-bit files... but I don't really care about Hi-Res, the market has been shady enough (oversampling of old recordings sold at a higher price) that it doesn't need another layer of shadiness imho.

Now, back to people expecting (and being promised/paying for) CD 44.1 kHz 16-bit data. They could be a bit unhappy when they only get 13 or 13.5 bits of DR on their non-MQA devices out of a stream that has been covertly converted to MQA or if MQA CD becomes the norm. Or if they are forced into MQA CDs...

If MQA becomes the standard, customers with MQA hardware will only lose 0.07 bit of DR (per marketing) but will be paying more (indirectly yes, but definitely more). Customers without MQA hardware will lose at least 2.5 bits of DR.

How is that progress for customers?
Without mentioning lossing EQ capability. Since "bit perfect" connection to the DAC is expected! I really do not understand how @amirm is ok with this, him being a proponent of EQ
 
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Because in ultrasonic band the content of music (just harmonics of increasingly lower magnitude) is NOT 24 bit deep, but as Atkinson's post says, 5 bits, and decreasing even more the higher you move in frequency. The rest is noise below, and empty bits above. And so, they don't need to pack 24 bits below the noise of the first 24Khz band, but instead much, much less (and btw, this is not a mysterious, hidden information; it is explained by MQA in their documents even with annoying detail).

Unless, of course, your signal is white noise of big amplitude or square wave, that instead DOES have very high amplitudes of harmonics in ultrasonic (and also in the high region of the sonic bandwidth). Which, btw, is the reason why Amir tests of DACs increase the band to ultrasonics when measuring square waves. That's why MQA performs bad with that type of signal: it is not intended to process that. One of the many reasons why these tests are flawed.

Btw, I can't figure out what's worse: if Archimago and GoldenEar didn't know that (almost unbelievable); or that they knew it and even then, they prepared a test file knowing the type of failures they would get.
So... MQA is not lossless then. Got it.

I also got this: "If your music is really noisy (and has only 13bit of data due to noise being 3bits) you really don't lose too much with those 3bits MQA steals"

Fine, but what about my music having not being that noisy and with a lower noise floor than 13bits?
 
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