MQA is Vaporware

[Doug Schneider]

I'm not going to wade into why these publications acted the way they did when MQA first came out -- and remained on that train even though some of the best experts in digital (Robert Watts, John Siau, among others) were waving red flags left, right, and center. Instead, I want to bring up something I believe is critical that is potentially very destructive regarding MQA and most people are not talking about -- the implementation of the MQA filter as the sole playback filter for all files.

 

Many designers I've talked to (and I've talked to many) have said that ideally, MQA wants their filter used for all playback. If I'm not mistaken, a number of DAC makers did just that -- used the MQA filter for all PCM routed through. The problem is, while the MQA filter might be fine for MQA playback, from what I've learned, it's not the best filter for standard PCM -- it's a very "leaky" filter, among other issues. That said, IMO, those suppliers that implemented the MQA filter for all playback may have severely compromised their DACs doing so. I know I would never buy a DAC that has only the MQA filter.

 

Thankfully, though, not all companies did that. The Hegel H390 that I have here supports MQA, but it has dual paths through the filters for MQA and non-MQA material, as have others. But it's something I believe that potential buyers should look into. This, to me, is crucial -- but why didn't the magazines that championed MQA report on that? One can only guess...

 

Doug Schneider
SoundStage!

 

 

[Doug Schneider]

13 minutes ago, Kal Rubinson said:

I did report on this particular issue and, generally, agree with your comments about it.

Good! More have to be informed.

The irony of this is that I believe that those audiophiles who rushed to buy DACs with MQA filters in them (just like those who rushed to buy DSD-capable DACs even if they didn't have any DSD files) might try to quickly unload them once they find out it might not be as good as it could've been if the MQA filter is all there is (which is why I give Hegel credit for sticking to their guns and implementing MQA their way).

Doug
SoundStage!

[Doug Schneider]

1 minute ago, Thuaveta said:

 

If you're in the process of reviewing the Hegel, and it does the same type of back/forth switching as the iFis and the dCS', would you mind considering asking them a rough estimate of how many man-hours went into getting that to work ?

 

(and yeah, it's totally to quiet the "but... but... but... MQA is FREE to the consumer !!!" type arguments some of the shills like to try)

 
Sure.

Doug

[Doug Schneider]

26 minutes ago, John_Atkinson said:

 

Stereophile has done with every DAC that did that, Doug. See, for example, my technical analysis...

 

Come on, John. We've been around the block more than a few times on these topics -- well, maybe not this one, so let me have a go.

 

You casually mention it in the technical measurements, by your own admission here. But have you actually put something in bold like you did with "MQA's Sound Convinces Hardened Showgoers" or the umpteen other articles that trumpeted this brave new digital world?

 

I think in service of the readers, an article about this titled something like "Warning to DAC Purchasers - Watch Out for How MQA Is Implement In Your DAC" might've brought the subject more to the forefront. Then explore it instead of grand-standing with those VERY flawed listening tests that got the front-page news.

 

And in case you think that's not necessarily your job to (I would think the Technical Editor would willfully explore these subjects in great detail), your boss, Paul Miller, did a good job of bringing to light the aliasing artifacts that can arise from the MQA process -- and even allowed me to reprint it with permission in my article, which questioned those things, too.

 

https://www.soundstagehifi.com/index.php/opinion/1104-mismatched-masters-and-false-frequencies-is-mqa-better-worse-or-just-different

 

I think if servicing the readers is #1, the pros and cons should be equally distributed. That's how I see it, anyway.

 

Doug Schneider

SoundStage!

[Doug Schneider]

17 minutes ago, crenca said:

 

Interesting how JA uses refers to this issue as "this problem", yet his publication did not say it was a problem as such, they just noted it...in the context of Stereophiles otherwise breathless promotion...so a reader would read this qualification in the positive and not negative.

I think "breathless promotion" sums up what clued me into this whole MQA thing. Frankly, back when this whole thing was beginning, it was a sideline thing to me, but then a couple manufacturers literally called me up and asked, "Why are these magazines promoting this MQA thing so heavily." So I started looking into it and my eyes opened wide -- questionable listening tests and the publication of articles like this one (which I just Googled and quickly came up):

 

https://www.stereophile.com/content/mqa-questions-and-answers

 

The TAS articles were worse, though.

 

Has any non-proven, questionable technology EVER been given this type of platform -- with no one on the other side in those same places saying "Wait, hold on, let's see what's really here." I don't recall it. "Breathless promotion" seems right.

 

I've taught my two boys an important lesson -- when you make a mistake, face up to it and admit it. Seems like the only way out.

 

Likewise, if I thought I made a mistake a few years ago when I started questioning MQA, I would admit it RIGHT NOW. But on this topic, I don't feel I have.

 

Doug Schneider

SoundStage!

[Doug Schneider]

11 minutes ago, crenca said:

 

Have you ever parsed this article Doug:

 

https://www.theabsolutesound.com/articles/master-quality-authenticated-mqa-the-view-from-30000-feet/

I remember that -- it was something. But nothing -- and I mean NOTHING -- comes close to this:

 

https://www.theabsolutesound.com/articles/let-the-revolution-begin/

Doug

[Doug Schneider]

5 minutes ago, mansr said:

In terms of quality loss vs size reduction, it's actually one of the worst. In fact, I can't think of any other format that increases the size while losing quality.

If I recall, someone compared an 18-bit/96kHz FLAC file to an MQA file and found that it was smaller. Hmmmm...

 

Doug

[Doug Schneider]

Something that's always baffled me about the MQA debate are the champions who proclaim that somehow MQA is NOT PCM-based. That it's something beyond.

Let's see...

 

- you take a PCM file of whatever resolution...

 

- you compress it using a lossy technique to a proprietary format...

 

- you then uncompress it back to a reasonable facsimile of the original PCM file and that plays back.

 

And what isn't PCM about it?

Doug

[Doug Schneider]

1 hour ago, John_Atkinson said:

 

Nothing I write is "casual," Doug.

 

Of course not John -- the words always come from high up on a mountain.

 

Now come on, though -- let's talk for real. As a former editor, you're not going to try to tell me that your measurements and text get looked at more than the reviews. If they do, I think they should headline the equipment reviews and the subjective evaluations should be cut down to one-fourth.

 

With that in mind, a mention buried into a measurement write-up is, well, buried, isn't it? Like I said, I've never seen a topic like this one on the filter get a bold headline anywhere in your magazine or the website -- but the casual listening tests where no verification of the source material do get out there. So like I said, let's get real.

 

As for Charles Hansen, in the last months, I talked to him more than anyone else I know -- he would phone me and talk for hours. Literally hours. And a lot of that was on MQA. I can say that you can't try to equate your thoughts with Charles's. He was aghast at the MQA promotion in the magazines -- and you know that from Audio Asylum. And as to the minimum-phase filters, Charles was equally aghast that you couldn't separate that from the MQA puzzle. "He likes the sound of an minimum-phase filter. Why doesn't he says that instead of all this bullshit about MQA?" (There were probably quite a few more expletives, actually.)

 

Doug

[Doug Schneider]

2 minutes ago, esldude said:

Preferences need no justification, but one of the big issues in audiophiledom is confusing preference with fidelity and truth.  

 

And that is a really, really good point. What sounds "good" isn't necessarily what sounds accurate. Really, to know that, you must, as you've done, be at the recording session.

When you look at the behavior of some of these filters, you do often see a frequency-response rolloff, so the question is: Is that softening the supposed time behavior or is it a frequency-response effect?

Doug
SoundStage!

[Doug Schneider]

1 hour ago, John_Atkinson said:

With playback of CD-resolution recordings, a slow-rolloff reconstruction filter typically gives a rolloff reaching between 1dB and 3dB at 20kHz. See fig.8 at https://www.stereophile.com/content/mytek-hifi-brooklyn-da-processorheadphone-amplifier-measurements for example, reproduced below. I doubt that is audibly significant. YMMV.

 

If you've ever played with tweeter rolloffs, 1-3dB is significant and clearly audible as you're usually talking about a fairly wide bandwidth in the top octave of the audioband. We recently received a speaker that allows .5dB adjustments in its topmost frequencies -- easily audible. Go take an equalizer and do the same thing -- you *should* hear it. And that hearing it will be a softer, more forgiving top end. Sound familiar?

Doug Schneider

[Doug Schneider]

2 hours ago, John_Atkinson said:

 

Fairly wide bandwidth? Not really, Yes, if you are talking about the level of a tweeter, I have found, in a blind test, that I can detect a level difference of just 0.5dB. But that 0.5dB difference covered 2.5kHz-20kHz, ie, 3 octaves, which is a large "area under the curve." In the case of the example of the slow-rolloff reconstruction filter I gave,  the output is flat to 10kHz, -0.1dB at 13kHz, -0.86dB at 17kHz, and -2.4dB at 20kHz, ie, the area under the curve is very small. And that area is in a region where human hearing sensitivity is reduced compared with frequencies below 13kHz. I doubt that it will be audible.

 

Not at all what I've found -- and what many designers I've talked to have found. We're not talking about starting so low in frequency, we're talking about the top octave of the audioband, so 10kHz upwards, which is precisely what you're talking about with these digital filters. As you know, I "talk shop" with a number of the world's top speaker designers and the difference of even 0.5dB in that top range can be significant enough to turn a speaker from "a little too bright" to "just right." In the case of one very famous and well-selling top-end loudspeaker, that's exactly the difference that was made in the final voicing. A 3dB difference in that top octave can be profound. So while you may doubt it, I don't doubt that it can be clearly audible.

 

Doug Schneider

SoundStage!

[Doug Schneider]

22 minutes ago, The Computer Audiophile said:

I've asked the MQA team for such information. I said I would happily publish anything that proves anyone wrong because I want the correct info. I offered to publish anything from anyone who can show MQA is correct in its assertions and the people here are wrong.

 

So far, nobody has taken me up. Makes me wonder. 

 

I would say who said this, but I didn't ask his permission, so I won't name him out loud. But when I told a top digital designer I couldn't get any technical details from the company to truly prove their claims, he replied with, "That right there should tell you what you need to know."

 

This whole deblurring thing, if true, could've been so easily proved. Get an ADC that's the supposed culprit. Record something that's "blurry." Then "unblur" it. Prove to everyone you can. Case closed. But no........... instead, let some audio writers tell the world it can and have them dig their heels further and further into the ground when asked.

 

I come from a technical background in IT -- any time someone came with some claim, the first thing you did was ask them to prove it. If they were real, they did.

 

Doug Schneider

SoundStage!

[Doug Schneider]

6 minutes ago, botrytis said:

 

This is one of the big issues. MQA hasn't proven anything about it. All they say, you know *WINK WINK* and that is it. It causes me to pause.

 

It should cause many pause for thought. Unfortunately, it didn't give some writers pause, but anyone with critical thinking skills would get their guard up. I gave it the benefit of the doubt, but when I asked for details and got NONE, sorry, that doesn't cut it...

 

Doug Schneider
SoundStage!

[Doug Schneider]

11 minutes ago, crenca said:

What Atkinson, Bob S, and others have is a philosophy that does not seem to rise above a mere (idiosyncratic)- audiophile assertion.  They then have devised a certain philosophy that "fixes" this problem, but of course this philosophy introduces other problems and trade offs.  Rather than being honest about this in a pro/con matrix, they announce Copernicus level "birth of new worlds".

 

I think what's unfortunate in this case is that this so-called philosophy and assertions, not supported by facts, has made any reasonable debate fruitless. One the one side you have people who want the technical claims proven and/or they've proven that they're not what they say, and on the other side you have people standing their ground -- even if there's no ground to stand on. They just dig their heels in and hope someone will believe them.

 

The truth of the matter is, however, that it really no longer matters. Any new technology has a limited time to catch on. A few writers in the flagging print press tried to make it their lightning rod a few years ago. MQA being picked up by Tidal WAS kind of a big deal -- but WAS was put in caps there for a reason. That's now ages ago.

 

Today, no one really cares and if Tidal goes away or flips themselves to FLAC files like other high-res services use, no one would be surprised. It's a small topic, really, that only exists in forums like this one and the odd article in an audiophile magazine from someone who won't let go. I feel no compulsion to write about it in any way on any of our sites. IMO, the marketplace has already relegated it to the scrapheap.

 

Doug

[Doug Schneider]

28 minutes ago, Ishmael Slapowitz said:

Did anyone note in Austin's Mytek review that he quoted a recording engineer as saying that a modern album may

go through as many 5 conversions by the time it is mastered? So does MQA "de-blur" and "correct" the timing for all

conversions? Me thinks not. Me thinks MQA was DOA theoretically and in practice on Day One.😍

 

This sort of thing came up time and again -- What about multiple conversions? What about multiple converter types? What if someone doesn't really know what converters were used? And on and on...

 

I think you're probably right about Day One.

 

Doug Schneider

[Doug Schneider]

2 hours ago, mansr said:

I don't doubt that, but it's still not an MQA filter.

 

My graph was created using the Matlab 'freqz' function with the actual filter coefficients extracted from a DAC.

 

2 hours ago, John_Atkinson said:

I do note that mansr's spectrum extended to >384kHz, which implies his analyzer supports an A/D sample rate of at least 768kHz. Perhaps he would share with us what analyzer he used. If, that is, he examined the analog output of a D.A processor and didn't simulate the spectrum with, for example, MatLab.

 

John Atkinson

Technical Editor, Stereophile

 

I don't expect John Atkinson to reply in any meaningful way to your comments. In this forum, he's showing that he's unable to having any meaningful dialog with someone who opposes something he wrote. That said, what I have to say is in relation to what you (mansr) did when you reverse-engineered the digital filter and found the 96kHz limit...

 

When I began looking at MQA, it didn't take long looking at their patent applications to figure out, in general, how they were packing their bits. But I couldn't figure out how they could claim higher and higher resolutions into the same 24/48 container. "Were they going more and more lossy?" I wondered. It didn't dawn on me that they weren't -- it was when you wrote about the downsample to 24/96 that I said, "Oh, that's how!"  If true, they're not packing higher and higher resolutions at all.

 

But before you published that, what reviewer who championed the format questioned how they could packed larger and larger files into the same size container, and who questioned if a downsample was happening? I doubt you'll find anyone thinking that way. In fact, you won't find much critical thinking.

 

What I wonder is why people don't ask more questions. Coming from an IT background in the 1980s and 1990s, when NOTHING WORKED PROPERLY, it was commonplace for us to walk into each others' offices, hang out in the halls, and trade information. You knew you couldn't know everything about everything, but you could sure as hell find someone who probably already figured out what you had to for any given projects that day. That's why these forums -- and the work of Mansr and Archiamago -- is crucial. Trading information.

 

By the same token, when I read that Naim Audio "downsamples" data in JA's technical measurements in this review, it gave me pause for thought: https://www.stereophile.com/content/naim-audio-uniti-nova-integrated-amplifier-media-player-measurements

 

But I didn't close the door on the thought. I got in touch with Naim Audio's director of engineering and asked them why they were downsampling data. He told me they weren't resampling anything -- that they design all their components to roll off output at about 27kHz (if memory serves me). He said that I should fine their preamps will do the same. Why not ask questions?

 

The point is, this is a new world where the exchange of information in the hallways of the 1980s and 1990s is now happening in near-real-time online. I just can't figure out why all those reviewers who championed the format did so from their silos, instead of looking outside their little worlds.

 

Doug

 

 

[Doug Schneider]

36 minutes ago, esldude said:

The whole MQA affair lacks transparency and honesty.  

 

I think, actually, this might be what comes out of this debacle -- a learning experience. The world's changed since the 1980s and 1990s. These days, online, you have an entire world of technically literate people connected. You can't come out with some story and just expect people to buy in. You're going to get questioned -- and HARD. If MQA had something to truly buy into, I think an open, transparent, highly technical discussion, with facts and proof and all that, at the start might've charted a different course. But that didn't happen, did it?

 

Doug Schneider

[Doug Schneider]

29 minutes ago, Jud said:

I think you’re being too charitable. They selected filters that no competent designer would choose for fidelity, because they knew many listeners subjectively preferred them, and said they corrected time domain errors in recordings, which these filters are incapable of doing. They used lossy compression that reduced fidelity, to try to protect their IP (while initially denying it was lossy). They gave a false impression of the original resolution of upsampled files. And they marketed it all as “Master Quality.”

 

You have me re-thinking my choice or words.

Doug Schneider

[Doug Schneider]

14 minutes ago, rwdvis said:

 

One of the biggest failures is the fact that BS and MQA failed to take this into account. ... We’re now in the information age where BS and misinformation have nowhere to hide.

 

When I was writing my first article about MQA, I was thinking about writing an article about this topic -- companies run by old men (and perhaps old woman) who really aren't that tech-savvy and haven't really caught on to how the whole world is connected. As I was writing, I knew they faced two real threats:

 

1) That exactly what happened ... happened -- people from around the world started talking about it and basically dissecting the entire thing.  We see that today.

 

2) The other was that some hotshot programmer from somewhere in the world would see the compression algorithm and not just knock it off, but write a better one and just give it away for free. That hasn't happened, but I could see it.

 

In any event, the "brave new world" that's out there has nothing to do with some music-compression scheme -- it's the worldwide collaboration of people.

Doug Schneider

[Doug Schneider]

2 hours ago, mansr said:

A clever guy named Josh Coalson already did. In 2001. He called it FLAC.

 

Well, then there's that! Of course you're correct. And it seems almost too good to be true -- and free! But in this case, it does all it says it does -- and that's a lot! (But there isn't the magic and mystery behind it that the writers who latched on to MQA seemed to adore so much.)

 

https://en.wikipedia.org/wiki/FLAC

 

Doug Schneider

[Doug Schneider]

22 minutes ago, james45974 said:

The key about FLAC as opposed to MQA is the concept of "royalty free licensing"

 

And that FLAC is a true lossless system.

 

Doug

[Doug Schneider]

3 hours ago, John_Atkinson said:

That experience is echoed every day in my endeavors to characterize the performance of the audio components reviewed in Stereophile - every product, be it speaker, amplifier, CD player, is fundamentally a black box with input and output terminals. All I have to do is ask the question ‘What does it do?’"

 

Hi,

 

While I can understand treating components as a black box -- when we put a speaker in the chamber and close the door on it, I tell people "now all the marketing claims and other hoopla go away, let's see what it does" -- I don't see why guessing at why something works the way it does, versus asking and finding out the answer why it does, is the way to characterize something.

 

For example, the reader is supposed to benefit from what they're reading. In this case, you "suspect" something, which is wrong. But instead of suspecting it, why not say, "I asked the Naim engineers about this measurement anomaly and they told me . . ." After all, does it matter if you suspect something if what you suspect is wrong?

 

And before you or anyone gets defensive about that, there's a reason that the saying "A jack of all trades is a master of none" exists -- can one person really be expected to know everything? This is even more true today with advancements in computers, even in hi-fi -- no one can know everything about what really goes on inside.

 

So while we each have our way of working, I favor the idea of getting the answer instead of guessing at the answer. I don't know how many times I've told my writers, "Instead of guessing, why don't you just ask something?"

 

Doug Schneider

SoundStage!

[Doug Schneider]

1 hour ago, Currawong said:

Much of the blame can arguably be laid at the feet of the people who generated the hype -- audio writers who seem unwilling to rock the boat by publishing the facts.  It'd probably only happen if a significant number of manufacturers approached the writers in person and had some hard words.

 

I think you hit the nail on the head here and I think this is also what any discourse on this has become so polarized. These audio writers came out of the gate with this thing that it automatically had those more critical taking a BIG step back and saying "hold on, what's going on here?" Now, there are two sides, far apart.

 

What needs to be found out, however (and it's probably impossible now to get anyone to admit anything), is how these writers became the champions of the format that they didn't bother to scrutinize.

 

Doug Schneider

SoundStage!