Stereophile Series on MQA Technology

[firedog]

4 hours ago, GUTB said:

Jim Austin's latest article seems to admit that MQA is lossy, as per CA's analysis. In that case, displaying the sample rate of the original in an MQA stream is both literally and subjectively deceitful. If MQA doesn't offer lossless, than don't suggest you do. We can content ourselves with "very good lossy" and if it sounds better than it sounds better.

 

Also. "Lossless compared to what?"....compared to a FLAC, ALAC, APE, or any other lossless format. Why is Jim tying himself into a rhetorical knot over this topic? Just say: "It's lossy" and then move on to discuss the nature of the lossy format.

 

What's "spectral components above 48kHz"?

Austin's argument is the same as MQA''s: that what is lost is only noise, so it is functionally (SQ wise) lossless. MQA also claims. of course. that their process improves the sound over the original. 

[esldude]

Austin's claims are so much the same as MQA's the by line should have read, Written by Jim "Bob Stuart" Austin. 

 

This is so disingenuous it makes me want to vomit.  

 

Is it a Freudian slip that the origami illustration uses a dollar bill?  You can't make this stuff up.  

 

Finally, we need to decide whether MQA is good or bad for music. We audiophiles probably won't get to decide MQA's fate, but we do get to have an opinion.—Jim Austin
 

So now though pitched initially toward audiophiles and sold as a boon for sound quality we are told, eh, audiophiles don't get to decide anyway.  They can have an opinion.  (for all the good it will do them is left unsaid)

[esldude]

From JA's writing:

 

If an MQA file is played without MQA decoding, the sound quality will be that of the baseband file—ie, the same as a CD—(hold on here JA, we already know from work of others it is an adulterated version of a non_MQA CD) meaning that the record company need stock only a single inventory. As well as the bandwidth benefit for streaming, there is another commercial benefit for the record industry with MQA that is not true of lossless-packing schemes such as FLAC: The record company will no longer be selling a clone of their hi-rez master. Instead, they are selling something that might well sound identical to the master, or even better than the master, but doesn't allow the master to be re-created.
 

So a benefit is rather than selling a clone of the master they sell something not a clone that sounds identical to the master. HUH?

 

Even more HUH? here we are again with something sounding even better than the master.  Yes, that is right.  A benefit is not having to sell a clone of the master, but selling a non-clone that sounds better than the master.  Yeah right.  That JA thinks we'll swallow this is a disgusting insult. 

 

So this is presumably why all three big record companies are on board.  Rather than sell master clones they'll sell us non-clones that sound better than the masters?   Bizarro world.   

[Indydan]

43 minutes ago, firedog said:

Austin's argument is the same as MQA''s: that what is lost is only noise, so it is functionally (SQ wise) lossless. MQA also claims. of course. that their process improves the sound over the original. 

 

With that reasoning, one could argue that mp3 only discards the unimportant bits of music. So mp3 is also lossless in that sense. The mental gymnastics and wanking by the MQA people is disingenuous. 

[esldude]

22 minutes ago, Indydan said:

 

With that reasoning, one could argue that mp3 only discards the unimportant bits of music. So mp3 is also lossless in that sense. The mental gymnastics and wanking by the MQA people is disingenuous. 

Well just to be clear, the people who created mp3 didn't claim or think it was transparent.  It was an attempt to make it as close to transparent as possible while greatly reducing bit rate in the days when bandwidth was much more restricted. Improvements have made it near transparent at higher bit rates though still not transparent.  So they are throwing away bits of music less important rather than unimportant.  

 

But otherwise, yes I agree with you, it is a case of disingenuous mental gymnastics in the case of MQA. 

[mcgillroy]

If anybody was in doubt Austins texts makes one thing clear:

 

MQA = MP3+

 

Where the + stands for:

 

-  only partially lossy

-  plus DRM

 

The whole argument for the folding process is pro perceptual encoding. By that logic they would need to rally behind MP3 & AAC too, cause those smart, smart enconders know how to distinguish noise from "meaningful" data.

 

Seriously this text is an amazing feat of syncopancy. Notice also not a word about compensating for ADC-deficiencies, its all per track analysis for encoding.

 

Now somebody print t-shirts and stickers with MQA = MP3+ and sell them at audio shows. Surely a hit with discerning Audiophiles. 

[Thuaveta]

For the curious, there's a wonderful talk on MQA right here. It might be a bit too reasonable and hydrogen-audio-ey for the wood-plug usb cable-set, but it's open-minded, structured, methodical, starts at the beginning and the "MQA is vaporware" thread is brought up.

[Shadders]

Hi,

I did not read the articles, but did search for "blur" in each. Not one mention of temporal blur.

 

I thought that temporal blur (dispersion) was the crux of MQA - else it is a lossy encoding of the master.

 

So, do we get to read how MQA de-blurs the file (which will be interesting, since it is impossible)

 

Regards,

Shadders.

[Confused]

26 minutes ago, Shadders said:

Hi,

I did not read the articles, but did search for "blur" in each. Not one mention of temporal blur.

 

I thought that temporal blur (dispersion) was the crux of MQA - else it is a lossy encoding of the master.

 

So, do we get to read how MQA de-blurs the file (which will be interesting, since it is impossible)

 

Regards,

Shadders.

3

3

Agreed.  However, note this at the end of the article.  All will be revealed.....  (maybe)

 

Footnote 1: I'll be writing more about MQA's time-domain claims in future articles.
 

[FredericV]

11 hours ago, firedog said:

https://www.stereophile.com/content/more-mqa

 

https://www.stereophile.com/content/mqa-tested-part-2-fold

 

Interesting that they seem to think the first MQA article showed that the time response of MQA is doing what it claims-I’m not sure it did.

 

At least JA does understand that there are DRM and consumer choice issues involved.

 

 

What a load of crap:

 

Quote

But as with every aspect of the codec, there's a serious philosophical perspective behind MQA's commitment to data-rate reduction. For Stuart, efficiency in the delivery of musical information is an aesthetic, even an ethical commitment.

 

Let's deblur this to:

 

Quote

The MQA encoder, he told me, can detect "spectral components above 48kHz," and has "several strategies" for dealing with it, including choosing from among more than 2000 encapsulation algorithms. The encoder will choose the option that will "allow the decoder to most accurately reproduce the signal 'envelope' and slew-rate." Does that mean that this musically relevant information is preserved—and how well? As I said, I'm not sure—Stuart never quite committed on this point—but it seems a lot of trouble to go to just to throw it out.

From the measurements we have seen so far, MQA throws away everything above 48 Khz. It replaces everything above 48 Khz with aliasing. Our reviewer has no means to validate Bob's claim. The reviewer tries to shine some light into a black box and fails. The secrecy of the black box allows this kind of BS to be published.

 

Quote

To sum up the losslessness issue: In its folding and unfolding, MQA distinguishes between music-correlated data and noise, tries hard to retain the music-correlated data, but sensibly worries much less about preserving the noise bit by bit. This allows MQA to achieve their goal of preserving the benefits of high-resolution data without the burden of large, weighty swaths of pointless noise.

 

This can also be obtained using the Xivero solution or similar strategies to blank the noise bits therefore reducing the entropy and thus file sizes. This achives a higher compression ratio than MQA's implementation.

And there is no need for a proprietary decoder. So which solution is than more ethical?

The last part where he can't hear the noise added by MQA basically debunks the need for high-res:

 

The noise level is similar to redbook noise. This again confirms MQA is somewhere around 15 ~ 17 bits of actual resolution. But it's enough for MQA to get away with it.

Image used in this post under fair use.

[Norton]

3 hours ago, Thuaveta said:

For the curious, there's a wonderful talk on MQA right here. It might be a bit too reasonable and hydrogen-audio-ey for the wood-plug usb cable-set, but it's open-minded, structured, methodical, starts at the beginning and the "MQA is vaporware" thread is brought up.

 

I didn't bother listening after reading multiple inaccuracies and slants just on the introduction:

 

Tidal charges  more for MQA than non-MQA? 

 

You don't own a MQA download?

 

If you apply DSP after decoding you lose  the MQA license (?) and get < CD quality?

 

I wasn't aware any of those things were true, or at worst were true of MQA in particular.  Objective  and reasonable?  Just looks like a particularly clumsy prejudged kill job to me.  

[james45974]

5 hours ago, esldude said:

Is it a Freudian slip that the origami illustration uses a dollar bill?  You can't make this stuff up.  

Yes, a very poor choice!  You would have thought someone on the ball would have used the piece of sheet music the dollar is sitting on for the origami!

[james45974]

1 hour ago, FredericV said:

The last part where he can't hear the noise added by MQA basically debunks the need for high-res:

On a similar thought about high-res, but maybe a little off topic for this thread, you can imagine that the big (subscriber-wise) streaming services are watching the Tidal high-res "experiment" closely and seeing that there is apparently little interest from the public at large for high-res, hence Tidal's moribund subscriber numbers.  I don't know if I would hold my breath about the larger streaming service offering high-res unless it is packaged as MQA, the whole single inventory argument may have traction.

[Fokus]

1 hour ago, Norton said:

If you apply DSP after decoding you lose  the MQA license (?) and get < CD quality?

 

You can only apply DSP properly after full decoding, but there is no decoder in existence that allows you to apply DSP to its output.

 

If you apply DSP before full decoding it will break the MQA code and will not allow you to decode.

 

The best one can do today is to take the unfolded digital output of Tidal or of a Node2 and apply DSP to that.

Even this was originally not allowed in the MQA paradigm.

[Ron Scubadiver]

With digital downloads there is no inventory.

[Norton]

1 hour ago, Fokus said:

 

You can only apply DSP properly after full decoding, but there is no decoder in existence that allows you to apply DSP to its output.

 

If you apply DSP before full decoding it will break the MQA code and will not allow you to decode.

 

The best one can do today is to take the unfolded digital output of Tidal or of a Node2 and apply DSP to that.

Even this was originally not allowed in the MQA paradigm.

 

But presumably you can apply whatever DSP you want to the decoded stream from Tidal desktop.  For example I can do whatever I want with the DSP options in my DAC once fed by Tidal MQA, the idea I then get  <  CD quality is patently absurd.

 

My real point though is that from the opening slide, it is clear that the scene is being set for propaganda rather than the objective analysis suggested above.  For example whether or not you own a download is a question that could be raised with any service or format (iTunes for example) it's nothing to do with MQA specifically.  Again the statement  that Tidal charge more for MQA, is disengenuous, Tidal charge more for all RBCD+ quality, not specifically for MQA.  By contrast with the scenario being hinted at here, most  Tidal subscribers seem pretty happy at getting MQA for no additional charge.

[Fokus]

10 minutes ago, Norton said:

 once fed by Tidal MQA, the idea I then get  <  CD quality is patently absurd.

 

 

In MQA parlance the output of Tidal is not "fully decoded".

 

Once truly fully decoded you no longer have access to the data, hence no DSP.

 

[mansr]

All this talk about impulses and transients is rather pointless without showing the regular, non-MQA performance.

 

Here's the step response (~5 ns rise time) of the Tascam UH-7000 ADC at 192 kHz:

 

And the response to a 2.5 μs pulse, about half a sample period:

The response looks a bit different depending on where the impulse lands relative to the sample points.

 

What exactly is the problem supposed to be here?

[crenca]

I want to give a shout out to @John_Atkinson for the "More on MQA" article.  As I said on your site, I could quibble (as some do above) but your recognition that MQA (or anything like it) is not just another audio product - that it has Net Neutrality like impact on consumers and their digital ecosystems is refreshing.

[John_Atkinson]

4 minutes ago, crenca said:

I want to give a shout out to @John_Atkinson for the "More on MQA" article.  As I said on your site, I could quibble (as some do above) but your recognition that MQA (or anything like it) is not just another audio product - that it has Net Neutrality like impact on consumers and their digital ecosystems is refreshing.

 

Thank you. But it is fair to note that I first wrote about MQA's potentially monopolistic benefit to the recorded music industry more than 3 years ago. I expanded on those thoughts for the essay in the February 2018 issue of Stereophile.

 

John Atkinson

Editor, Stereophile

[GUTB]

And yet—the Inconvenient Truth that MQA sound better is still with us. Last night I bough the 192 and MQA versions of the same album from hiresaudio and the MQA version is CLEARLY better. Since the booklet confirms that the album was mastered in multi-channel 24/192 with a stereo and MQA version also to be released (Japanese audiophile label UNAMAS) we are fairly well assured both versions are from the same source by the same engineer. This was on a Pro-Ject S2 that does native MQA full unfolding.

 

The difference was not small, and anyone with a native MQA DAC has had these experiences. What I’m really interested in knowing is if this is really the result of time domain deblurring or if there’s some form of EQ trick being applied. None of the MQA haters seem to be able to account for this and I hope Jim Austin can.

[semente]

14 minutes ago, GUTB said:

And yet—the Inconvenient Truth that MQA sound better is still with us. Last night I bough the 192 and MQA versions of the same album from hiresaudio and the MQA version is CLEARLY better. Since the booklet confirms that the album was mastered in multi-channel 24/192 with a stereo and MQA version also to be released (Japanese audiophile label UNAMAS) we are fairly well assured both versions are from the same source by the same engineer. This was on a Pro-Ject S2 that does native MQA full unfolding.

 

The difference was not small, and anyone with a native MQA DAC has had these experiences. What I’m really interested in knowing is if this is really the result of time domain deblurring or if there’s some form of EQ trick being applied.

 

You and others keep forgetting that there's also a chance that MQA produces one or several types of "euphonic" distortion which among other things add a perceptive sense of "enhanced spaciousness"... It's easier to like or dislike an aspect of reproduction than to describe it from an observationist perspective as objectively is as possible in a listening assessments.

 

What is an ear-bleeding distortion produced by a nasty cone resonance to you and me can be perceived as "liveliness" or "resolution" to others, just as flat frequency response can sound "boring".

[botrytis]

I find it funny and sad that Stereophile is so rabid about MQA. They really don't seem to want to hear the negative comments and tests that other websites, manufacturers an audiophiles have about it, like this page...

 

https://media.ccc.de/v/34c3-9113-mqa_-_a_clever_stealth_drm-trojan

 

and there are other. This all gives me pause.

[Shadders]

1 hour ago, GUTB said:

The difference was not small, and anyone with a native MQA DAC has had these experiences. What I’m really interested in knowing is if this is really the result of time domain deblurring or if there’s some form of EQ trick being applied. None of the MQA haters seem to be able to account for this and I hope Jim Austin can.

Hi,

I too, am interested in the reversal of dispersion that MQA claims to have perfected (we are told, we will be hearing it as per the mixing/mastering engineer, or artist).

 

If MQA have perfected the reversal of dispersion, then that patent alone is worth billions, and every communications entity (product makers and designers, suppliers, service providers, commercial, military, etc etc etc) will praise MQA for delivering the communications holy grail. Well done MQA.

 

Or it could be purposefully added distortion and equalisation, which everyone knows about.

 

Regards,

Shadders.

[#Yoda#]

1 hour ago, GUTB said:

And yet—the Inconvenient Truth that MQA sound better is still with us. Last night I bough the 192 and MQA versions of the same album from hiresaudio and the MQA version is CLEARLY better. Since the booklet confirms that the album was mastered in multi-channel 24/192 with a stereo and MQA version also to be released (Japanese audiophile label UNAMAS) we are fairly well assured both versions are from the same source by the same engineer. This was on a Pro-Ject S2 that does native MQA full unfolding.

 

The difference was not small, and anyone with a native MQA DAC has had these experiences. What I’m really interested in knowing is if this is really the result of time domain deblurring or if there’s some form of EQ trick being applied. None of the MQA haters seem to be able to account for this and I hope Jim Austin can.

 

I wonder why you use for you comparison explicit a quite cheap "mass market" DAC, very good for the price, no doubt, but sonically not on one level e.g. with the Mytek Brooklyn, that is for his part not even a "reverence" for digital/analog conversion.

Not really suitable to your self-expressed high end claim.