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MQA is Vaporware


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17 hours ago, fung0 said:

 

As a journalist who's spent decades reviewing all kinds of electronic equipment, including audio gear, I can offer some perspective.

 

First, let me point out that it's difficult to buy a good review by letting the reviewer keep a bad product. Also, practically speaking, it's impossible for reviewers of expensive equipment to remain current without at least some 'long term loans.' But in the case of MQA, specifically, what would reviewers get to keep? If it's a DAC, its real value doesn't depend on its MQA capability. The manufacturer will probably be very happy if the review says "It's a terrific DAC, but the MQA stuff is a waste of time."

 

This actually happened in The Netherlands. Ruud Jonker, a very technical person, also a mastering & studio engineer, and an IT specialist, and also reviewer for Music Emotion, wrote a very good review about the Mytek Brooklyn, but had serious reservations about MQA.

Ruud is not a parrot which copy pastes the official marketing version, which is good. So even with a core feature the reviewer does not like, a product can still stand for all it's other features.

I use the Mytek not for MQA, but as a tool to see what resolution (bit depth + sample rate) is going into the DAC coming out of our music server. The Mytek can clearly figure out if S32_LE PCM data is 24 bit with zero padding or 32 bit, which for DSP makes a difference


 

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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3 hours ago, Shadders said:

What would be good is an idiots guide as to the claims made by MQA Ltd, and the actual truth - so those people who have no technical capability can see the opposing (truthful ??) facts. I can see the question and answer session on this site, so if some of those key answers were commented upon - as an example :

 

"Q82 i) “MQA have around 13 Bit of “lossless” information and everything below 14 Bit is “lossy”

 

This is incorrect. In general, the MQA system can reach in excess of either 23-bit dynamic range capability or 3–6 bits below the content noise in the audio band."



How is 23 bits of dynamic range possible, if 17 bits of the 24 bits distribution file are already borrowed to reconstruct the partial ultrasonics? Remember that MQA can't describe any ultrasonic frequencies above 44.1 or 48K (depending if the original resolution is a multiple of 44.1 or 48K), as the second unfold is minimum phase upsampling + weird filters. The first unfold adds one octave compared to the undecoded version. The second unfold does not recover any new entropy, and does not recover any extra additional octaves.

Why can MQA get away with only 13 bits of resolution (in case of MQA CD) or 17 bits (in case of 24 bit distribution files)?

This is very easy to explain:

No music content has 24 bits of actual resolution. I recently had the chance to record K's Choice in Koor (= in choir), an acoustic concert with a 240 voices choir in deSingel in Antwerp.
 

K's Choice in Koor

 

This concert hall has an RT60 of 2,03 seconds, which is ideal:

https://desingel.be/nl/info/blauwe-zaal

 

Let's look at RT60. RT60 basically debunks the need for 24 bit:

http://hyperphysics.phy-astr.gsu.edu/hbase/Acoustic/revtim.html

 

Quote

The choice of the relative intensity to use is of course arbitrary, but there is a good rationale for using 60 dB since the loudest crescendo for most orchestral music is about 100 dB and a typical room background level for a good music-making area is about 40 dB. Thus the standard reverberation time is seen to be about the time for the loudest crescendo of the orchestra to die away to the level of the room background. The 60 dB range is about the range of dynamic levels for orchestral music.

 

So if an orchestra has about 60dB of dynamic range, we need 10 bits of resolution. So if MQA claims "3–6 bits below the content noise in the audio band", this can actually be true,  but MQA also debunks the need for 24 audio bit depth.

MQA CD can perfectly get away with 10 bits of musical content + and 3 extra bits below the content noise in the audio band for some extra headroom, to land at only 13 bits of actual audio+noise, and 3 secret encrypted DRM bits, do recover some lossy ultrasonics and add one extra lossy octave compared to redbook quality.

With 24 bit distribution files, they most likely have 16 bits for the baseband audio, and 8 encrypted lossy DRM'ed bits to add an extra octave. So again, with 24 bit distribution files and 10 bits of real audio data like the dynamic range of a typical hall like deSingel in Antwerp, the claim of  "6 bits below the content noise in the audio band " can be true.

MQA basically debunks the need for 24 bits of audio bit depth

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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20 minutes ago, lucretius said:

 

But you can copy MQA files, assuming you can purchase them. The DSD file on an SACD was never intended to be copied.

Also, the "quality degraded version" you speak of does not really seem that "degraded" as far as I can tell listening to tracks from Tidal.

 


For now the distribution method is "Informative", but the patent allows DRM to be applied in totally different ways, and they can change their game once MQA has a bigger market penetration:

https://www.google.com/patents/US20160005411
 

Quote

The methods of the current invention can support several commercial models for distributing audio in which the delivered file can convey a compatible but reduced quality but whose full quality can be decoded and confirmed by methods which combine Song and Device and User keys. The distribution methods may be: “Informative” where the decoder confirms that a legitimate stream is decoded by a legitimate decoder; “Restrictive” where the transaction server can limit the full quality playback to combinations of Users and Devices; “Trace” wherein songs contain embedded information which may displayed in whole or in part during playback or forensically, the removal of which prevents subsequent lossless recovery; “Positive” where the previous methods can provide an enhanced yet restricted distribution wherein the server permits copies to be gifted from one User to another.

 

and:
 

Quote

It is assumed that the account holder will possess one or more players, each of which is able to decrypt an item that has been encrypted with a user key specific to the account holder, and also possibly with shared user keys or a universal user key that is common to everyone. The method encrypts the song key with an appropriate user key so that only players that know that user key may retrieve the song key, which is generally common between performances of the method on a given song. This feature allows the steps of reversibly degrading and embedding to be performed once and the result stored in a server, only the remaining steps being repeated for each transaction relating to a given song.


With MQA you don't own the master, but the right to play it back either in a crippled way (where this can be manipulated to sound like CD or all the way downgraded below MP3 quality), or in an approximated way (which also undoes some of the crippling).

Their DRM allows phone home, and they can change their game.

MQA is indeed very bad for music.

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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2 hours ago, mcgillroy said:

Especially since we don't know how key-managment is implemented. Is MQA controlling the PKI and handling root-keys + signing processes?

 

Anybody shed some light on this? Michael can you ask Bob if you get the chance?

 

It's a fact that studio's still don't have access to an encoder. So MQA holds all the cards related to signing the files.
No mastering engineer signs the files. It's all done in an MQA facility.

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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4 hours ago, Fokus said:

 

Yes. You can record from the Tidal desktop app. It is a bit laborious.


The desktop version of Tidal uses encrypted flac files. So you can't intercept the flac files over http, as the file looks like garbage.
But Tidal also has non-encrypted versions for devices that don't support encryption. These files are protected with a token system.

Tidal files played via the desktop app and chrome are already encrypted. Add MQA to the mix, and we have:

- encryption of the flac file without using HTTPS
- ecnryption / obfuscation of the pseudo highres part of the MQA file used for the unfold
- authentication via MQA
- DRM with degrading up to MP3 levels (see the patent) for those without an MQA decoder

MQA hardware decoding modules have the possibility to add an ID number, which increments for every module sold. Phone home DRM based on the ID of the MQA decoder is technically possible looking at their patent, but impractical for now.

It would require a lot of middleware to be added to Tidal to have per customer locked MQA files. It would also imply modifying some flags in the files, or use an out of band system to check if the customer has the right to play the file, which will add a lot of complexity and break current implementations.



 

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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It seems MQA has their own loudness war on unaware players

 

While reading [0025] ... [0027] of the patent, which describe the deliberate degrading of the sound by messing with the gain,


https://www.google.com/patents/US20160005411

 

it mentions Peter Craven's patent:

 

Quote

The representation is deliberately degraded in a reversible manner, for example by applying a time-varying gain as described in published International patent application WO2013/061062, incorporated herein by reference, so as to provide a lower sound quality when the song is played by an unaware player as if it were a standard PCM signal.


So which artist would allow the deliberate degrading of their work, as mentioned in 26?

 

Quote

The first purpose is to allow the degradation to be reversed on playback; the second is to allow the degradation to be selected on artistic, aesthetic or commercial grounds by the artist or his representative and to be consistent for all account-holders who may purchase the song.



The real issue is their artificial loudness war. Let's look at their gain manipulation:

https://patentscope.wipo.int/search/en/detail.jsf?docId=WO2013061062

Abstract:

 

Quote

Some methods employ complimentary amplification and attenuation, while others employ gain redistribution. Pre-emphasis and soft clipping techniques are described as methods of losslessly reducing the peak excursion of the PCM audio signal.


The above & claim 32 basically describes compression:

 

Quote

32. A method according to any of claims 26 to 31 , further comprising the step of:

losslessly pre-emphasising (70) the digital audio signal in order to reduce the amplitude of frequency components that have high energy.


So it seems MQA has their own version of the loudness war (=dynamic range compression / gain manipulation) as a feature, to cripple playback on non-licensed or MQA unaware players, in order to make the difference with decoded MQA bigger.

Please convince me how this is not bad for music.

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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https://www.gearslutz.com/board/12847173-post86.html

RMAF has cancelled the MQA Panel.

 

Quote

This was to be Sat 12noon in prime time with Richard Schram owner of Parasound moderating. MQA rep Mike Jbara bailed first on his desire to talk with me ahead of the panel, then RMAF cancelled the panel. Coincidence or pattern? You decide. I would bet my savings they were pressured to do so by Jbara or Stuart in the face of a serious panel with serious questions.


They must be very afraid of Brian Lucey and those with real questions

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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1 hour ago, The Computer Audiophile said:

Berkeley is in a unique position, having spent millions of dollars on research for the previous company Pacific Microsonics.

 

https://www.gearslutz.com/board/mastering-forum/1101429-mqa-39.html

 

Quote

Further, the founder of PM, now Berkeley Audio AGREES THAT MQA on PCM is destructive, he sees this stage as a necessary evil to get to all MQA world, round trip for all.


Grammy award winning engineer Brian Lucey who is against MQA, uses PM converters.

So why did Berkeley make a 180 degree turn?

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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3 hours ago, miguelito said:

"My assessment is that MQA is definitely different, and usually better. Not night and day better, but better. Think about it. This is music arriving in your room via the Internet, for a fairly minimal monthly charge—an exponentially increasing body of recordings for playback with sound quality that’s, at the very least, as good as the best present  high-resolution digital files."

 


When no more technical arguments are left, the MQA key opnion makers always fallback to one of these 2 options:

- you must go listen
- or post their standard time domain argument, with some copy paste journalism

So what did we do? We bought an MQA DAC, put it in a nearfield setup with Amphion Two 18, a big Vitus amp, and listened to DXD vs MQA files from 2L.no

I was first tempted by more echo & reverb in the MQA files, but something was missing in voices. It also sounded thinner. These are subtle not day and night differences, but the fact that the DXD sounds different from the MQA version, de-authenticated the A in MQA. Only one can be the studiomaster quality.

Studio's like 2L.no have worked years ago on their DXD masters. These were already available in 2013 when we entered the music server world. Those DXD files are 2L.no's reference of the studio sound.

2 years later MQA enters the market.

Now the MQA version with de-blur via their weird filters is supposed to be the new definition of master quality, while it's actually a  post-processed version of the original master, de-authenticating the originality.

Since day 1 I find the A in MQA misleading and false advertising.
The A should be Augmented or Approximated, otherwise it's misleading.

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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11 hours ago, james45974 said:

When will the first manufacturer get the idea that they have been hoodwinked to give away their family jewels (their DAC tech to MQA for filter implementation) and walk away.


Are MQA's NDA's in two ways? Do they protect both parties? What if MQA / Bob Stuart violates the copyright of the DAC designs of their MQA partners? What are the penalties? Or is it just a one way document, like most EULA's, where one party sets all the rules, and the other party has to blindly accept?



 

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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4 hours ago, Shadders said:

Hi,

What is intriguing is that MQA Ltd have to approve the DAC design.

Why would you need to approve the actual physical design of the DAC, if all MQA is, is just an IC ?

Could it be something to do with the requirement that the digitally unfolded signal cannot be sampled - for recording.

Does the design of the DAC have to include the physical protection of the DAC IC and MQA chip interface ?

Regards,

Shadders.


In some implementations, MQA is basically an XMOS board with I2S in and I2S out, this allows all inputs to go through the MQA decoder.

In other implementations , the MQA decoder is sitting on the USB input board, so instead of USB -> internal I2S, the board has USB->I2S->MQA->I2S to backplane. This only works for USB.

In other implementations, a full MQA software decoder (doing first unfold + renderer) is sitting on an ARM based board, which also functions as network bridge.

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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17 hours ago, Shadders said:

Hi FredericV,

Thanks. The design seems easier than the secrecy that surrounds it.

Is a network interface required in all designs ?

Thanks and regards,

Shadders.


DAC's with MQA don't check the network (for now) and lack a network interface, but DAC's support a unique serial for each decoder, which in theory can be tied to a user via DRM, when reading their patent. It can even be done offline, just like a DVD player checking if the region code on the disk matches what is in the firmware.

For MQA files, that could be (speculation) matching the serial nr of the dac to the serial nr encoded in the MQA file for a given user. So DRM could in theory encode some flags in a file so that it only plays on certain serial nr's of dac's (basically an access list). This would require some kind of synchronization scheme, where to user can enter the serial nr of his DAC when buying MQA files. Or the serial nr could be read via USB. But for this to work, there need to be an infrastructure that manages the ACL's and DRM.

So while current MQA files are not limited to certain users via DRM and access lists, once MQA starts to gain momentum, that could all change. It's already mentioned in their patent.


 

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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5 hours ago, realhifi said:

Just noticed this ad for NAD’s new receivers. The ad is in Sound & Vision which is as mainstream as A/V gets. Look closely at bottom left of ad that lists features of the receiver. Looks like slightly more than vaporware at this juncture. 

D7552A41-4F7E-4E87-A737-4E63914BD3ED.jpeg

 

Nothing new here, an NAD with a buesound raspberry alike ARM board.
 

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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Just now, firedog said:

No, I think you are over interpreting it. The analog output section of the DAC (not the DA converter itself) has a tube. So as far as the end result, it's no different than using a non-tube dac and a tube preamp. So why should MQA care? 


I used to sell tube dacs/amps/cd-players, and solid state dac's. The output sounds completely different.

What is your affiliation with MQA?

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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5 minutes ago, firedog said:

Apparently MQA only cares that the DA conversion is properly "deblurred", as they refer to it in their universe. Once that has happened, they don't care if you pass the signal through a tube, a transistor, an output  transformer or a whatever. In their terms, once they've supplied you with the properly reconstructed signal they've done what they promised - if you want to muck it up after that, it is your choice. 


To measure the transient response of a dac and how it deviates from the ideal transient response (like in my metrum adagio, MQA can't correct anything, it has no pre- nor postringing), you need to play transients, and record the analog DAC output, then look at the transient response to see the ringing artefacts, and correct them as a total system (e.g. in case of MQA using weird filters).

It's not possible to measure a tube DAC without the tube, or measure it's response as if it's a solid state DAC.

It simply does not work like that.

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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1 hour ago, crenca said:

 

 

Thanks for the write up Frederic.  Just to be clear, the active speakers do not have a DAC (and thus a 2nd A>D>A conversion) correct?


The speakers have XLR & IEC power inputs at the bottom. Internally every speaker has four amps.
All processing / filtering is in the analog domain. There is no extra AD/DA


 

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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1 hour ago, Pure Vinyl Club said:

 

Hi, FredericV. 

How could you play on Antelope Zodiac Platinum (which is not MQA) native MQA files?
Please explain in more detail the whole process of listening ...


The zodiac platinum will accept 24 bit in any samplerate up to 384K, so those decimated MQA files which are typically 24/44.1 or 24/48 will just play, but with a higher noise floor as 9 bits contain the control data and secret DRM encrypted MQA non-nyquist data, which a normal dac will play as noise. When using sox based resampling, the difference between the original DXD master (in case of 2L.no) and upsampled MQA using nothing more than the 24/44.1 or 24/48 files and no licensed decoder, becomes so small it cannot be distinguished under blind testing, even on the most expensive sets. Most are guessing or can't tell them apart. In the test we did on the show, nobody could even numerate any difference between both.

Anyone can peer review the test:
http://www.digitalaudioreview.net/2017/07/kih-46-mqas-missing-link/

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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41 minutes ago, psjug said:

 

 

Because air attenuates ultrasonic frequencies transmitted >3m.  So a terrible problem (sarcasm).  See Page4 here

http://www.aes.org/tmpFiles/elib/20171005/17501.pdf


So this means in a 1000 seat concert hall like de Singel in Antwerp
 

K's Choice in Koor



most of the ultrasonics are gone, because of the distance:
ultrasonics-attenuation.thumb.png.fd6b7ed57888e8997b35352e185a2a8d.png

 

I was in the 7th row and at least more than 10m from the choir.

Video done with Nikon D750 and no tripod (I was to make photo's but it was so impressive I started recording):



My colleague Kommer Kleijn made me aware of the above curves, and that this is an actual problem in PA design. It's even more a problem outdoor, with changing weather conditions, temperature, humidity ....

I made recordings of this hall, and indeed, the highest frequencies are severely attenuated. The unamplified sound of the choir is also much better than the artist K''s Choice playing via the PA. Furthermore this hall also has reflector panels, making the traveled distance of sound even longer, which is mixed with the directional sound.

For those listeners in the rear rows of the hall, all the ultrasonics are gone. Sarcasm indeed.

Designer of the 432 EVO music server and Linux specialist

Discoverer of the independent open source sox based mqa playback method with optional one cycle postringing.

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