MQA Deep Dive - I published music on tidal to test MQA

[Jimbob54]

@amirm, Within the many audio communities, you are a very public internet figure. Your expressions and motives can and will be discussed in many forums, especially given your strong defense of MQA, which is very puzzling to many of us.

To be fair, it's not so much a defence of MQA but a rebuttal of the challenge. I dont think I have seen him advocate in favour of MQA- just that it doesn't concern him.

 

[stopbeingalentil]

Not at all. There is for example "perceptually lossless." This is when you tell a lossy encoder to produce the highest quality it knows, and have the bit rate vary. This is as special VBR mode that is available for some lossy codecs. We had this at Microsoft and in vast amount of content it was transparent and about half the size of mathematical lossless.

"perceptually lossless", by definition, depends on the perception of the listener, ergo will be different for every single person and even for every possible permutation of gear combinations of every single person... in other words "perceptually lossless" is a pretty worthless claim

 

[stopbeingalentil]

Personally I'll be interested to learn how much damage are done to non unfolded files as this is how I'll be using MQA content forced on me.

AFAIK this is impossible so far as part of the full unfold is exclusively done in hardware. So the best you can do is compare analog recordings of your DAC's output, which could then easily be criticized for being not accurate unless you're really carefully setting up that experiment

 

[bboris77]

"perceptually lossless", by definition, depends on the perception of the listener, ergo will be different for every single person and even for every possible permutation of gear combinations of every single person... in other words "perceptually lossless" is a pretty worthless claim

After a few drinks, the definition of "perceptually lossless" becomes very fluid.

 

[stopbeingalentil]

After a few drinks, the definition of "perceptually lossless" becomes very fluid.

After a few drinks is also when you can easily say "yeah, deblurring my audio would be very nice" xD

 

[Pennyless Audiophile]

Firstly: MQA could never be lossless when they claim to "improve" anything. Being lossless means being identical to the original output. If you change anything about that, then you're not lossless any more.

As to MQA's influence on real music:
View attachment 132379
Here's a spectrum difference of "Poppy"'s "Concrete", which is available as MQA on Tidal. The comparison is between the 44.1/16 file from Qobuz and the 44.1/16 file from Tidal (ie. "Hifi"/non-mqa)... This both shows that you still get the MQA encoded file even if you select "CD-Quality" in Tidal and how the MQA encoding fucks with the sound even in the audible band. Whether that's generally audible is a different question but the difference is significant nonetheless.

Since one is from Tidal the other from Qobuz, are we sure that the masters are the same? It is common practice to have different masters for different streaming services. (I am not defending MQA here, just trying to understand if the problem exists or not).

 

[muslhead]

To be fair, it's not so much a defence of MQA but a rebuttal of the challenge. I dont think I have seen him advocate in favour of MQA- just that it doesn't concern him.

This
Amir should understand since he has been in management that a leader needs to take a position, any position and then explain why and how he got there. This ambivalence (for the lack of a better word) is what bugs me. I dont care if he agrees or disagrees with me but rather i have no idea on what he stands for on this important item. Maybe its my fault because i am too dense to get his position. A big shout out and thumbs up to @JohnYang1997 for his position. He is a leader and setting the example on how to do it right. He took a position, stands for it but I believe is open (upon proper evidence) to change it. That is what leaders do.. For me its about leadership (or lackthereof) on MQA since i dont know enough to make a correct decision and am looking to those who know more to help form my opinion.
Sorry for the continued edits but i also want to again thank goldenone (amrir its not goldeneye ) for his work. Dont be discouraged by those who are trying so hard to disparage you and your work. It is appreciated.

 

[bboris77]

This
Amir should understand since he has been in management that a leader needs to take a position, any position and then explain why and how he got there. This ambivalence (for the lack of a better word) is what bugs me. I dont care if he agrees or disagrees with me but rather i have no idea on what he stands for on this important item. Maybe its my fault because i am too dense to get his position. A big shout out and thumbs up to Johnyang for his position. He is a leader and setting the example on how to do it righ. He took a position, stands for it but I believe is open (upon proper evidence) to change it. That is what leaders do..

And to also support this point for @JohnYang1997, it's not that he just came out with this position now after the whole MQA discussion exploded. He openly expressed his disdain for it a long time ago, despite the fact that Topping's own DACs offer an MQA choice.

 

[muslhead]

And to also support this point for @JohnYang1997, it's not that he just came out with this position now after the whole MQA discussion exploded. He openly expressed his disdain for it a long time ago, despite the fact that Topping's own DACs offer an MQA choice.

I learned the hard way that is what leaders need to do, some never do unfortunately.

 

[stopbeingalentil]

Since one is from Tidal the other from Qobuz, are we sure that the masters are the same? It is common practice to have different masters for different streaming services. (I am not defending MQA here, just trying to understand if the problem exists or not).

No, I don't know this but subjectively both versions sound the same in terms of mixing and tonality. So that coming from the same master is an asumption on my part. I will also admit that the two versions are perceptionally virtually identical.

That said, the Deezer 44.1/16 is identical to the Qobuz one iirc, which could indicate that there really is only one master.

 

[BDWoody]

To be fair, it's not so much a defence of MQA but a rebuttal of the challenge. I dont think I have seen him advocate in favour of MQA- just that it doesn't concern him.

I think people are upset that he just doesn't care about it as much as they think he should. He is a leader in the movement to more objectivity in the audio world. Is that in doubt? That doesn't mean he has to pick up every torch that gets thrown at him and magnify it with his his endorsement on this bonfire of a site.

He's chosen his battles, he doesn't have to care about MQA.

 

[Jimbob54]

I think people are upset that he just doesn't care about it as much as they think he should. He is a leader in the movement to more objectivity in the audio world. Is that in doubt? That doesn't mean he has to pick up every torch that gets thrown at him and magnify it with his his endorsement on this bonfire of a site.

He's chosen his battles, he doesn't have to care about MQA.

Possibly- but his continued engagement with the threads like this rebutting some of the challenges to MQA might give some cause to think he does care, just not in the direction they would like. Personally, his or anyone elses views on it doesnt bother me either way. I've seen enough to make my mind up about it - my hope is that is becomes more of an irrelevance rather than gains any further traction.

 

[tmtomh]

SO he is testing a market claim. That he accomplished.

MQA is countering saying that if you feed the codec music instead of test tones, they do indeed preserve its fidelity using that triangular encoding method (as opposed to rectangular encoding of PCM). OP's test did nothing to test this. To the extent MQA is able to do that with music, then OP didn't accomplish anything other than getting a few lines changed in a Wiki/marketing pages. Content owners will still be able to be convinced that with real content, the process is "lossless."

This is a very useful comment, I think, because to me it reveals the core of the problem I have with your arguments about MQA, Amir. (To be clear, not saying I have a problem with you - just saying I have a problem with your argument on this particular topic.)

The problem, as I see it, is this: when you say MQA "do[es] indeed preserve its fidelity using that triangular encoding method," the definition of "fidelity" you are operating with there is not the same definition of "fidelity" that forms the foundation for the entire purpose of this site, including all your reviews and all your measurements.

MQA encoding purposefully reduces the fidelity of the digital music data you put into it, and it does so for two reasons. One of those reasons - to preserve ultrasonics - you know is pointless since we don't hear those frequencies. The other reason - to "deblur" the music by applying slow, apodizing filters - you know is pointless at best and damaging at worst, since you have noted in countless reviews the problems with slow/leaky filters.

So the best-case scenario is that MQA files sound the same as PCM files. But even in that best-case scenario, MQA files use lossy encoding in order to achieve signal-processing goals that you yourself have repeatedly said are pointless and/or undesirable.

 

[dorirod]

I don't get why MQA is so determined to hold onto the lossless thing. It is lossy and they pretty much have conceded this with the scrubbing of their original "MQA Lossless". Seems to me they could just say "very best fidelity" or something like that.

Two reasons I think:
1. It would be an ackowledged strong item in the con side, with nothing on the pro side.
2. That would move the goalpost to just how lossy is it, and they really don't want to invite more scrutiny.

 

[aarrel]

Not at all. There is for example "perceptually lossless." This is when you tell a lossy encoder to produce the highest quality it knows, and have the bit rate vary. This is as special VBR mode that is available for some lossy codecs. We had this at Microsoft and in vast amount of content it was transparent and about half the size of mathematical lossless.

MQA proposes another form of lossless that says it music follows statistical distribution, they are able to fully preserve its actual informational content including what is in ultrasonic. If they are able to achieve this fully, what is your beef with it? That it doesn't spit out a bunch of bits for a rectangular channel is not used in music?

When we want to say the same bits come out that go in, we clarify with the term "mathematically lossless."

Remember, there is no lossless codec that works for all content. Here is the wiki on that: https://en.wikipedia.org/wiki/Lossless_compression

"By operation of the pigeonhole principle, no lossless compression algorithm can efficiently compress all possible data. For this reason, many different algorithms exist that are designed either with a specific type of input data in mind or with specific assumptions about what kinds of redundancy the uncompressed data are likely to contain."

The code books in lossless codecs for example are trained on a specific dataset which in this case would be music, not random test signals. Lossless codecs can actually make the output larger than input! When this happens, they cheat and just pass the input to output. MQA can't do that because it explodes the output so it complains with error messages.

Amir from Audio Pseudoscience Review strikes again..

 

[Jimbob54]

Two reasons I think:
1. It would be an ackowledged strong item in the con side, with nothing on the pro side.
2. That would move the goalpost to just how lossy is it, and they really don't want to invite more scrutiny.

And the whole "as the artist intended/ just like the master" provenance schtick collapses in on itself the minute it is , in fact, not. And never was. That really was the only pro for the consumer, all the others were for the labels/ content owners and of course Bob.

 

[dmac6419]

This
Amir should understand since he has been in management that a leader needs to take a position, any position and then explain why and how he got there. This ambivalence (for the lack of a better word) is what bugs me. I dont care if he agrees or disagrees with me but rather i have no idea on what he stands for on this important item. Maybe its my fault because i am too dense to get his position. A big shout out and thumbs up to @JohnYang1997 for his position. He is a leader and setting the example on how to do it right. He took a position, stands for it but I believe is open (upon proper evidence) to change it. That is what leaders do.. For me its about leadership (or lackthereof) on MQA since i dont know enough to make a correct decision and am looking to those who know more to help form my opinion.
Sorry for the continued edits but i also want to again thank goldenone (amrir its not goldeneye ) for his work. Dont be discouraged by those who are trying so hard to disparage you and your work. It is appreciated.

You can make that determination on your own,,me personally I don't need Amir or John Yang to make that for me, people get caught up in the codecs trying to over analyse without listening to the music,if it sounds good to you than it's good for you.

 

[dmac6419]

Amir from Audio Pseudoscience Review strikes again..

What's your technical background,I listen to music doesn't count, you a musician, engineer,you building something?or are you that goldenear fella.

 

[voodooless]

Amir should understand since he has been in management that a leader needs to take a position

Nonsense. @amirm is no leader (well, possibly to the mods, but not otherwise). He's just the gracious host of this forum. Why would you expect him to take a position because of that? What would he taking a position bring to the table that other users can't? Amir can have any position he likes, even an ambivalent one, just as anyone else.

 

[pozz]

This is wrong. Since the MQA process is closed and proprietary, the only people able to understand it in full are MQA themselves. Everyone can only chose to believe what they claim.


So they claim without providing any proof of it, without stating their testing methodolog. At the same time they actively work against independent efforts to test their claims.

At any rate what stands, imho, is that MQA is to no benefit for the consumer whatsoever.

@Archimago did a lot of research and seems to understand the innards pretty well. @mansr did some serious work on the filter function. Plus there is the JAES publication. We don't need 100% knowledge. We have enough to say it's lossy, it aliases, has frequency dependent dynamic range, etc.

By "actively work", are you at all surprised? They will fight for their income. In the corporate world, especially when you have investors and huge debt to finance the project, and other covenants through contracts with third parties, and plus a large public presence with interested media, your everyday pressure is through the roof. This trickles down from top to bottom and everyone involved. It's to be expected that they will be aggressive. If they have a legal department you can bet that the marketing material and the reply to @GoldenOne were vetted as well. Might even explain some of the obtuse language.

MQA is a closed loop like the Dolby tech. I'm sure there are other examples in audio, but I can't help but keep coming back to vinyl and tape, which were commercial products marketed as hifi whose direct competitors were live music and radio (edit: the original lo fi). We are used to the hardware requirements of that media now, but it was (edit: is) still a closed loop. MQA revived the paradigm in a new way with modern tech by creating a compressed hi res digital file, capitalizing on all of the prior marketing, attention and demand on that front. It's a commercial venture.

Gear testing already gave us the way forward: get the data and present it well. The results will speak for themselves.