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There’s a lot of information and misinformation floating around about MQA: How does it work? Is it lossy? Does it have DRM (Digital Rights Management? And so forth.
This is understandable since MQA, for good reason, has not openly published the details of their protocol and it uses a different kind of compression paradigm than normal where some words and phrases have a different meaning in the context of MQA than they do with MP3’s, FLAC files, etc.
I should say that I have no business relationship with MQA, no real inside information from them, and neither mean to be an advocate for or against it.
However, if you follow a lot of the publicly available information about it, sort of read between the lines, and collate all the information, you can suss out what it does if not exactly how it does it.
First, most forms of compression irretrievably throw away information and/or compact it in a way that can be undone. They work in a linear, or “horizontal”, way on the bitstream, meaning that they look at the numbers and find ways to reduce the space needed for them often using something called pattern recognition. They generally make no attempt to analyze what is represented by the bitstream (MP3 does a little but only to determine what to discard without the intent to replace or reconstruct what’s lost) and move things around, or “down” and “up”.
MQA takes a more “vertical” approach by moving high-frequency musical information into the lower frequencies and masking it with dither, a kind of randomized form of information almost like white noise, that masks the embedded high frequencies to make them virtually inaudible. This is why MQA-encoded files are backwards-compatible and can be played without decoding at the compressed level (such as 44.1 or 48kHz). MQA calls this process “folding” because it repeats the process each time it cuts the required bandwidth in half. So 192kHz gets folded to 96kHz and then again to 48kHz (or 176.4 to 88.2 to 44.1). This is basically what Bob Stuart of Meridian and MQA calls “audio origami”. Yes, this gets done in a lossy way but not lossy as is thought of with an MP3 because MQA never claims that the missing information is “psychoacoustically irrelevant” or that it can’t be recovered.
The “unfolding” occurs in a series of steps sometimes in software and sometimes in hardware. So 48kHz gets unfolded to 96kHz and then again to 192kHz. The resultant bitstream does have some missing information; but MQA also encodes the difference between this final unfolding and the original analog waveform, and this difference gets used by an MQA-enabled DAC to reconstruct or “decode” all of the original information, so, in a full implementation of the MQA playback chain, the result is the same as lossless compression.
Yes, MQA does use “authentication”, which is a poor choice of words, because it’s really “verification”. Unlike DRM, the authentication doesn’t prevent you from copying your music files around or from playing them in a non-MQA system. It’s just a reality check that occurs before the unfolding and decoding to make sure that your file actually is MQA encoded, otherwise there’s no point in trying to unfold and decode it.
Some software, such as Roon and Audirvana Plus, can perform an initial unfolding from 48kHz to 96kHz, which will play through a non-MQA DAC. Although the 96kHz stream will not (yet) be fully reconstructed, it will have more more high-frequency information than the fully-compacted 48kHz stream so has a genuine potential to sound better.
Some people claim that even a fully-compacted MQA file will sound better, without any unfolding or decoding, than a non-MQA file with the same resolution. I have no way current way to verify this myself and it may be very subjective. However, I have never read anyone say that the MQA file sounds worse.
Apparently the way that MQA encodes the stream helps to improve the integrity of the signal in the time domain, where human hearing is much more sensitive than it is to the frequency or amplitude domain (remember the problems with jitter). Again, I have no current way to prove or disprove this but, if it’s correct, it would certainly be a plus.
Again, none of this information comes from a single authoritative source, is subject to revision, and certainly in no way indicates how to recreate the process. However, I am reasonably sure of its accuracy and it helps to explain some of the confusion centering on lossy versus lossless compression and DRM, among other things, when it comes to MQA. Ultimately, you have to decide if you enjoy it yourself. Like your mother used to say, “How do you know that you don’t like vegetables if you don’t try them?”
More to follow …
Good start Steve. My thought is buying the music all over again. That is the real issue. Dedicated 44.1 from a dedicated transport and DAC for me is superior.
Who, but Japanese audiophiles, has bought any MQA discs? The whole point of MQA is you NEVER have to buy another version of the files, because the high-rez version is there, available any time you want to decode it. Lastly, the whole point of MQA is for streaming, not for physical media. And you don’t buy a stream, you rent it…kind of like beer 🙂
I’ll confess that I bought a copy of Trondheim Soloisitine’s “Relfections” CD, just because I wanted it, but it also turned out to have MQA copies of the music files. It sounded great!
I think your point is correct, though, all of the OTHER MQA titles I listen to come via the nice folks at Tidal. Weirdly, I still buy CD’s even of titles that are currently available on Tidal, mostly classical stuff, not entirely sure why other than I like to collect physical things and downloads just don’t have the same endorphin reaction for me
Hi , Once again I see a very strongly titled article pushing MQA, but this time stating a strong opening title– “facts vs fiction…” Yet…it seems to me you’re not confident in your “facts” regarding MQA. I don’ think “fact” belongs in the title. Example, statements deflecting responsibility like: “Again, I have no current way to prove or disprove this but, if it’s correct, it would certainly be a plus.” Facts??? You wrote a guess, or hypothesis.
Lastly, your conclusion to your last paragraph to part 1, (“Like your mother used to say, “How do you know that you don’t like vegetables if you don’t try them?” ) wow, ….patronizing seems to soft to describe it. It certainly doesn’t give me a vote of confidence that you have no idea what you’re talking about and are just selling snake oil. I know audiophiles can be cult like, but most I know are not children who need encouragement to proceed based on…nothing. You stated nothing that hasn’t been said in the past four years, or five?
Why do I even care? I don’t…It just doesn’t feel right, your article. Like it’s 1934 in Germany and facts are inconsequential to a wanna-be scientific sector of audio. If you aren’t familiar with Xivero Algorithm Engineering out of Dussledorf, they make great apps and have some decent credibility among digital trend followers. Check out their 3 or 4 year old hypothesis on MQA–just looked, last version updated 2017. Anyway, It’s along the lines of your article without the pressure to “just try it, for Christ’s sake!”. They have to use hypothesis and logoc to determine whether MQA is a valid alternative to what we have now. Without the “Just try it, you won’t turn into a zombie and eat someone’s face, these are German bath salts!” https://www.xivero.com/de/hypothesis-paper-to-support-a-deeper-technical-analysis-of-mqa-by-mqa-limited/
FYI – the byline is Andy Schaub. Nice, subtle, Ad Hominem by the way…but not surprising…
????
This was an article that I wasn’t aware of — thanks for the link. Another excellent analysis that explains the technical/scientific reasons why MQA is not a solution to any current problem in high-end audio.
Here is Bob Stuart’s reply to the Xivero post (english) https://www.stereo.de/artikel/bob-stuart-interview-in-voller-laenge
In my experience and for my taste, MQA files streamed in Tidal DO sound better than their non-MQA equivalents. And this in my simple computer setup (PC to IFI Nano IDSD Black Label DAC with MQA rendering). The music sounds “clearer” and more articulate. I’d love to hear them in a better system. Streaming’s the whole point of MQA in my view. Otherwise there’d be no need to compress (or fold) them…
You cannot know if the 2 files are from the same master so observations like this mean nothing.
By definition they won’t be from the same source as MQA fixes issues in the time domain. If you’ve ever heard high end clocking in a studio context you know what a huge difference this can make.
Fact: Yes, this gets done in a lossy way but not lossy as is thought of with an MP3 because MQA never claims that the missing information is “psychoacoustically irrelevant” or that it can’t be recovered.
The “unfolding” occurs in a series of steps sometimes in software and sometimes in hardware. So 48kHz gets unfolded to 96kHz and then again to 192kHz. The resultant bitstream does have some missing information; but MQA also encodes the difference between this final unfolding and the original analog waveform, and this difference gets used by an MQA-enabled DAC to reconstruct or “decode” all of the original information, so, in a full implementation of the MQA playback chain, the result is the same as lossless compression.
MQA is both lossy AND lossless. MQA is Schrödingers format.
There is some fallacy in this article. First, MQA IS lossy. It removes information that you can NEVER get back. Secondly, 96/18 is the max for the first unfold. The second unfold is basically oversampling, so there IS NO true 192 or above file. Thirdly, the leaky filters used by MQA cause problems with accurate playback. This can be heard as in the extra noise file. Fourth, the dsp used, as part of MQA, means you cannot use digital volume control our your own dsp system and the playback of MQA file will be louder than the same FLAC file. Fifth, the compression of an MQA file with FLAC is way less efficient, so a supposed 94/24 MQA file is not smaller than the actual 96/24 FLAC of the same file. Sixth, you do not know what master is used for MQA files so trying comparisons is impossible to do.
I use both digital volume control and EQ and MQA flawless since the BluOS module for my NAD C390DD was introduced. The lossy aspect of MQA is only for the higher frequencies above 48 kHz. The size of the MQA files compare to 16/44.1 is indeed large, but it is still smaller than 24/96. Exact information and CD, DSD, HD and MQA music files can be found here: http://www.2l.no/hires/ The exact same masters have been used for this testbench and MQA is defined as ‘original resolution’ which was the reason for me to ask the recording engineer why this is. His answer is clear : (PV) Hello Morten, I have a question: why do you describe MQA as ‘original resolution’ compared to DXD, DSD and FLAC downloads?
(ML) Hi Peter! “MQA Original Resolution” is quite literally the sample rate and word-length used at each and every recording preserved thru editing mix and mastering into the MQA container. For recordings originating from our latest generation of the Horus AD converter the amount of deblur process is minuscular. For older recordings the deblur is more substantial. Yes, I would say that MQA is an even more fine-tuned sonic experience of our recordings than the straight PCM.
(PV) Thanks! Question: may I quote your remark above regarding deblur and PCM?
(ML) Please feel free to quote
(ML) What I find difficult to understand is why so many are afraid to trust their own sonic experiences? It’s my number one priority in masterclasses; not to tell the students what to hear, but to let their mental and physical guard down — be exposed — and trust what they hear.
Sorry no. Work done by people like Archimago and others have shown everything that MQA has said to be false and misleading.
MQA to me is a cash grab only. It does nothing new.
Lossy is lossy. We dont know what the affects of removal of that material affects the sound. No reputable experiments have bern done to show either way. I have listened to albums, that i know well and are recent releases, sound way different and NOT better when encoded with MQA. They sound fake and sparkly but if you feel that this particular sound is what they went for, in the studio, then why does the regular FLAC version sound different? I mean the guitars on the MQA version do not sound crisp and the cymbals sound like after thought noise.
I do not want to buy another DAC just to have MQA and I don’t stream and do not use Roon. Like I said, it is a cash grab. The studio pays MQA for the encoding algorithm, the DAC producer pays to use the MQA decoder, we pay more for the music to get MQA files and lps. The only ones winning are MQA.
The technology is a great step forward and especially cymbals, piano strings sound better in my system. I was positively surprised to read this on the WADAX website. A company who developed a super DAC, costing 65 grand and they added MQA on top of their technology and write this: ” During Audioexotics SuperShow in July in Hong Kong, a very interesting session was held. The focus was to do an A-B of MQA vs Non-MQA of the same track. This demo has been the first A-B public session like this in Asia. Javier Guadalajara, CEO of Wadax conducted the session and answered to the different questions that arised from the audience. The 1h session was perceived as too short, based on the interest and feedback from attendees. We promise to arrange a more extended one next time!… The result was unanimous: MQA tracks are so much better than regular, non-MQA ones.
Congratulations to MQA for bringing such an advancement for the enjoyment of music lovers and audiophiles. MQA certainly brings us closer to the real thing, which is the only parameter that matters to Wadax.”
How can a lossy compression system be a atep forward? Every MQA track I have heard sounds nothing like the regular FLAC version. You say it is a step forward, how? I see it as a technology, that is 10 years behind the times, looking for a niche to belong in.
Hate the name. Can’t they call it MP5 or something.