Article: MQA: A Review of controversies, concerns, and cautions

[Rt66indierock]

1 hour ago, Samuel T Cogley said:

 

Any idea of how much?  Just trying to divine the threshold of "significant" investment.

 

The 2016 MQA Ltd Consolidated Statement of Cash Flows shows all capital contributions to be less than 60,000 Pounds. That is the year the labels got their equity and some employees as well. That is not significant to me when the 2015 capital contributions were just over 14,250,000 Pounds.

[FredericV]

Excellent article.

Regaring footnote 25:

 

Quote

Of interest, it appears that only the “baseband” bits are being “authenticated”. In an experiment here by FredericV, when the lower 8 bits are dropped, the MQA “blue light” still shines even though it’s recognized as 16-bit audio. Maybe this is all that MQA-CDs are?

On a related note, doesn’t the fact that this blind spot in the authentication mechanism exists immediately disqualifies the MQA blue light from being something a consumer should have any faith in that the file is of “guaranteed” provenance?


 

This is indeed true for older Mytek Brooklyn firmwares. Using the latest firmware, the blue MQA dot will shine with original MQA files, and also with the sabotaged MQA files,  both showing 24 bit 352.8K in case of 2L.no demo files.

So the customer does not know if the file has been truncated or not. He does not know if he has a full first unfold, or partial first unfold.

Furthermore, when NOT truncating the file, only a small part is added back to the decoded output (light purple), compared to the spectrum that is generated by MQA's leaky filter (dark purple), which adds content above 20 Khz which does not even exist in the 16/44.1 file, due to aliasing.

As this small part is encapsulated in the lower  8 bits of the 24 bit distribution file as non-audio data, it does not compress with flac, making the flac size twice as large for a 24/44.1 MQA file vs 16/44.1 truncated MQA file in a 24/44.1 container.

 

Futhermore, sox filter settings exist which generate a very similar spectrum from a 16/44.1 MQA file:

[NOMBEDES]

3 hours ago, stevebythebay said:

I'm equally interested in both the feelings and actions of creative artists, those who represent the source of all the music that gets recorded.  Will they band together and form a "United Artists" of music to take on those industry participants of MQA who wish to adulterate their art?

 

 

Ask the old, original bluesmen who don't even have a headstone how well artists have done against the music industry.  Theft, shit contracts, exploitation, streaming payments, MQA, ......... the artists, for the most part, is not going to do well.   If you want to be an artist, you would be well served to get a lawyer for your 16th birthday.   Or have Taylor Swift's parents.

[Archimago]

24 minutes ago, FredericV said:

Excellent article.

Regaring footnote 25:

 

 

This is indeed true for older Mytek Brooklyn firmwares. Using the latest firmware, the blue MQA dot will shine with original MQA files, and also with the sabotaged MQA files,  both showing 24 bit 352.8K in case of 2L.no demo files.

So the customer does not know if the file has been truncated or not. He does not know if he has a full first unfold, or partial first unfold.

Furthermore, when NOT truncating the file, only a small part is added back to the decoded output (light purple), compared to the spectrum that is generated by MQA's leaky filter (dark purple), which adds content above 20 Khz which does not even exist in the 16/44.1 file, due to aliasing.

As this small part is encapsulated in the lower  8 bits of the 24 bit distribution file as non-audio data, it does not compress with flac, making the flac size twice as large for a 24/44.1 MQA file vs 16/44.1 truncated MQA file in a 24/44.1 container.

 

Futhermore, sox filter settings exist which generate a very similar spectrum from a 16/44.1 MQA file:

 

Great work FredericV on that script and the experiments you did.

 

I must admit I was surprised that the MQA system did not account for or "authenticate" those last 8-bits considering that the information buried there are what ostensibly makes the whole system "hi-res" in the first place! Truly, the blue/green/whatever color light is meaningless...

[Samuel T Cogley]

35 minutes ago, mitchco said:

 

@Samuel T Cogley re: the consumer is always right - perhaps audio enthusiasts need to take a page out of the gamer enthusiasts playbook who used social media to boycott the sales of Battlefront 2. Seemed to be very effective.

 

 

Unlike the situation with the record companies, Electronic Arts is singularly evil when it comes to business practices.  They are consistently near or at the top of the list of most hated companies year after year.

 

Especially because streaming providers are at the front of consumer's music consumption experience, record companies gain some measure of insulation from consumer wrath.  Witness not only UMG's copious use of audible watermarking in their streaming content, but also how utterly powerless streaming providers are to do anything about it.  UMG hasn't even acknowledged they're doing it.  I can't see how any boycott or any other consumer action could be effective there.  UMG has no accountability to their consumers, period.

 

Gaming resonates with a multitude perhaps orders of magnitudes larger than music consumers.  While I agree that EA was shamed into scraping their over-the-top greed with Battlefront 2, I don't see how this could apply to the record labels.

[asdf1000]

Finally something on the 'front page', as opposed to buried deep inside the threads.

 

I hope MQA Ltd do respond eventually. They seem to be using Stereophile as their technical outlet recently, so we'll wait for a response over there I guess.

 

[The Computer Audiophile]

36 minutes ago, NOMBEDES said:

 

 

Ask the old, original bluesmen who don't even have a headstone how well artists have done against the music industry.  Theft, shit contracts, exploitation, streaming payments, MQA, ......... the artists, for the most part, is not going to do well.   If you want to be an artist, you would be well served to get a lawyer for your 16th birthday.   Or have Taylor Swift's parents.

At the same time the artists to blame for signing their rights away. Nobody is innocent in this business. 

 

A story for another day. 

[mansr]

2 minutes ago, Em2016 said:

Finally something on the 'front page', as opposed to buried deep inside the threads.

 

I hope MQA Ltd do respond eventually. They seem to be using Stereophile as their technical outlet recently, so we'll wait for a response over there I guess.

Lavorgna will post some snark on Monday or Tuesday. Stereophile will follow up with an infomercial ghostwritten by Stuart a week later.

[The Computer Audiophile]

22 minutes ago, Archimago said:

 

Great work FredericV on that script and the experiments you did.

 

I must admit I was surprised that the MQA system did not account for or "authenticate" those last 8-bits considering that the information buried there are what ostensibly makes the whole system "hi-res" in the first place! Truly, the blue/green/whatever color light is meaningless...

Is there any way to upsample a track and have it still illuminate the light?

 

im just thinking about ways unscrupulous people have sold music and things MQA says it prevents. 

 

If its possible to hack MQA into illuminating the light that’s one thing, but if standard nefarious methods can do the same, that’s a much larger issue  

 

Not a positive either way though. 

[The Computer Audiophile]

Hey @Rt66indierock - Anything in the latest trove of Spotify documents about MQA?

[Rt66indierock]

12 minutes ago, The Computer Audiophile said:

Hey @Rt66indierock - Anything in the latest trove of Spotify documents about MQA?

 

I have the IPA from the SEC. Nothing in the first 50 pages in fact there is more emphasis on advertising and the free tier than I expected. Best line so far we have paid artists and labels more than 8 billion. Further into the document they talk about accounting issues concerning royalties and those pesky lawsuits. It is a great read so far.

[SlimPickins]

16 minutes ago, The Computer Audiophile said:

Hey @Rt66indierock - Anything in the latest trove of Spotify documents about MQA?

 

From Business Insider article today...

http://www.businessinsider.com/spotify-early-investor-northzone-cut-out-labels-2018-3

(login required)

 

Record labels will be the preserve of mega-artists like Coldplay. Tabitha Fireman/Getty
Spotify revealed its financials in its filings to go public on Wednesday.
The numbers show that Spotify bleeds a huge amount of cash by paying out to rightsholders — and most artists don't see a lot of that money.

Northzone partner and former Spotify board member Pär-Jörgen Pärson said Spotify's long-term goal is to cut out record labels to benefit artists more.

But more niche artists could use Spotify's platform to reach paying consumers directly.

Artists will soon treat Spotify as a kind of DIY record label, uploading their music and having a direct financial relationship with customers.
 

 

[mansr]

22 minutes ago, The Computer Audiophile said:

Is there any way to upsample a track and have it still illuminate the light?

 

im just thinking about ways unscrupulous people have sold music and things MQA says it prevents. 

 

If its possible to hack MQA into illuminating the light that’s one thing, but if standard nefarious methods can do the same, that’s a much larger issue  

 

Not a positive either way though. 

The blue light goes on if the top 16 bits match the cryptographic signature. That's probably difficult to fake. Let's say it's impossible. All that means is the file has been passed through a genuine MQA encoder with the right private keys. It says nothing about what the input actually was. If you send an upsampled file for encoding, you'll get back a signed MQA file claiming to originate from whatever fake sample rate you provided.

[rickca]

30 minutes ago, mansr said:

The blue light goes on if the top 16 bits match the cryptographic signature. That's probably difficult to fake. Let's say it's impossible. All that means is the file has been passed through a genuine MQA encoder with the right private keys. It says nothing about what the input actually was. If you send an upsampled file for encoding, you'll get back a signed MQA file claiming to originate from whatever fake sample rate you provided.

So the whole assurance of provenance thing is just a story.  The blue light is assurance that the potential MQA DRM mechanism is intact.  The file is therefore considered genuine from an MQA perspective.  In the imagination of marketing spin, it's the sound of the studio.

[FredericV]

1 hour ago, The Computer Audiophile said:

Is there any way to upsample a track and have it still illuminate the light?

 

MQA supports the case where the first unfold is done in software like Tidal (the output of the 1e unfold has a stream in the LSB bit which has signalling info that is detected by the renderer), and the second unfold aka renderer in the DAC. So Mansr can confirm or not if you can create fake 24/96 or 24/88.2 bit files with a pattern in the LSB bit of a simulated first unfold, that will trigger the blue light. I did not check those tools yet.

Our experiments manipulate the input files of the first unfold. But messing with the output of the first unfold while leaving the control stream intact, is another experiment that could be done. The same perl tool I wrote can be reused, all I need to do is not mess with the LSB bit.

What we did is manipulate the lowest 8 bits in MQA files. Either blank them (all bits zero), change them into a repetitive ascii string, or replace them with random garbage. All these files authenticate.

In case of 2L.no, mqa files render 24/352.8, while with the manipulated version, the data to reconstruct the ultrasonics is gone, but the MQA light still shines, and the display still says 24/352.8. Older firmwares told the partial truth: 16/352.8

So this is as bad as upsampling.
 

Quote

im just thinking about ways unscrupulous people have sold music and things MQA says it prevents. 

MQA uses the same tricks. It relies on upsampling to do it's trickery.

Suppose your input file before MQA encoding is > 96 Khz (eg 24/192, 24/384, 24/176.4, 24/352.8 ..... ) . They reduce the bandwidth to 88.2 Khz or 96 Khz (so in the analog domain 44.1 or 48 Khz) which they fold to a 24/44.1 or 24/48 distribution file. Anything analog above 44.1 or 48 Khz is lost. But the MQA dac could fool the customer into believing this is 24/352.8 or 24/384.

Even a file from 2L.no truncated to 16/44.1 still shows 24/352.8K on my Mytek.

This is false advertising and would not work in my country. One ISP sold a subscription "fibernet". So customers were fooled they were given fiber speeds, but the network was HFC, so fiber to the curb instead of fiber to the home. This ISP had to change their advertising into adding something like "fiber to the node".

So applying this to MQA, MQA would need to change the indication on my mytek with MQA files to something like: "Upsampled resolution: 24/352.8" instead of showing "24/352.8".

Something like "unfold 24/44.1 => 17/88.2, upsample to 24/352.8" would also be more accurate, but this will most likely never happen.

 

Quote

If its possible to hack MQA into illuminating the light that’s one thing, but if standard nefarious methods can do the same, that’s a much larger issue  

 

Leaky upsample filters such as a modified sox filter, can do a very similar spectral response for a 16/44.1 MQA file as MQA's own upsample filter. Which means the spectrum above the baseband is partially or 100% fake (depending on the resolution of the encoder input file). There's a good example in Archimago's article:

 

 

Mind the MQA gap.

 

 

[John_Atkinson]

3 hours ago, crenca said:

  I should note the one exception I know of which is JA's "More" opinion piece where he notes (after getting DRM factually wrong) that an end to end closed format could have the same impact on musical consumers as Net Neutrality could have on the larger consumer world...

 

Thanks for adding this comment Crenca. The essay can be found at https://www.stereophile.com/content/more-mqa

 

John Atkinson

Editor, Stereophile

[mansr]

19 minutes ago, FredericV said:

Mansr can confirm or not if you can create fake 24/96 or 24/88.2 bit files with a pattern in the LSB bit of a simulated first unfold, that will trigger the blue light. I did not check those tools yet.

I have a tool to do just that. However, this gives a red or purple light, not blue or green. There is no cryptographic authentication at this stage.

[FredericV]

5 minutes ago, mansr said:

I have a tool to do just that. However, this gives a red or purple light, not blue or green. There is no cryptographic authentication at this stage.

Does this mean that when a user has Tidal doing the first unfold, and then some MQA dac for the renderer, there's no longer a blue light shining on the MQA dac?

What I intend to test, is to mess with the 24/88.2 or 24/96 first unfold, leave the signalling bit intact, and flip or set bits in other parts.

[botrytis]

WOW, great article. I can understand why MQA didn't want to respond back. What could they say to debunk this article, w/o sounding like they are putting out more nonsense?

[mansr]

9 minutes ago, FredericV said:

Does this mean that when a user has Tidal doing the first unfold, and then some MQA dac for the renderer, there's no longer a blue light shining on the MQA dac?

Right. If the DAC supports this at all, you'll get a red light. Mytek DACs do this. Some others, e.g. the Meridian Explorer2, do not.

 

9 minutes ago, FredericV said:

What I intend to test, is to mess with the 24/88.2 or 24/96 first unfold, leave the signalling bit intact, and flip or set bits in other parts.

There's no checking of the data bits here. This is how we obtained impulse responses for the Dragonfly and Mytek Brooklyn DACs.

[oneway23]

A fantastic summation of the efforts of all of the folks here.  Congratulations on a great article, Archimago!

[scan80269]

Bravo, Archimago, for this concisely well-written article!

 

For a number of years I've been a fan of linear-phase digital reconstruction filters.  My current DAC, the Auralic Vega, offers a linear-phase filter option that I use to the exclusion of other options.  Your article here, as well as postings on your site, have me thoroughly convinced of the sonic merits of linear-phase phase filters over all the other types.

 

I also recently did a speaker crossover shootout between IIR parametric filters and FIR linear-phase filters, at a retired colleague/friend's venue, and using a miniDSP 2x4 HD box to implement the crossover filters.  Guess which filter type came out on top?  Both filter sets have exactly the same frequency response, but the difference in phase response between the filters is clearly audible, at least within my circle of audiophile friends.

 

Thank you also for your "Audiophile Myth #260: The Detestable Digital Filter Ringing and Real Music...".  My friend and I resonate extremely strongly with this article.

 

I've been very satisfied with the sonic performance of my Auralic Vega, but if I'm to contemplate moving to another DAC, it will definitely need to have FIR linear-phase filter as a user option.  A DAC without linear-phase filter support will never get my money.  DACs featuring MQA will fail to make my list to begin with.

 

Congratulations, again!

 

[scan80269]

deleted

[skikirkwood]

Thought I'd post a screenshot of my posting here before my comment is deleted and I get banned from Audiostream tomorrow morning.

[Archimago]

27 minutes ago, scan80269 said:

Bravo, Archimago, for this concisely well-written article!

 

For a number of years I've been a fan of linear-phase digital reconstruction filters.  My current DAC, the Auralic Vega, offers a linear-phase filter option that I use to the exclusion of other options.  Your article here, as well as postings on your site, have me thoroughly convinced of the sonic merits of linear-phase phase filters over all the other types.

 

I also recently did a speaker crossover shootout between IIR parametric filters and FIR linear-phase filters, at a retired colleague/friend's venue, and using a miniDSP 2x4 HD box to implement the crossover filters.  Guess which filter type came out on top?  Both filter sets have exactly the same frequency response, but the difference in phase response between the filters is clearly audible, at least within my circle of audiophile friends.

 

Thank you also for your "Audiophile Myth #260: The Detestable Digital Filter Ringing and Real Music...".  My friend and I resonate extremely strongly with this article.

 

I've been very satisfied with the sonic performance of my Auralic Vega, but if I'm to contemplate moving to another DAC, it will definitely need to have FIR linear-phase filter as a user option.  A DAC without linear-phase filter support will never get my money.  DACs featuring MQA will fail to make my list to begin with.

 

Congratulations, again!

 

 

Thanks for the note Scan. I certainly would not have said it years ago when I first started writing about this stuff, but it is fun putting ideas and articles out there with the hope that they resonate and can be useful for others as these ideas and tests have been useful for my own listening and understanding...

 

Yeah, I'm not surprised of the results with your work on your friend's miniDSP system. I'm sure @mitchco also has had a lot of experience with these configurations and getting the time-domain "just right".

 

21 minutes ago, skikirkwood said:

Thought I'd post a screenshot of my posting here before my comment is deleted and I get banned from Audiostream tomorrow morning.

 

skikirkwood: Good luck on both counts! :-)