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

[PO3c]

A decoded MQA is not less than a CD. It is more.

More of what? It would be nice to see more measurements as to what there is more of? OT seem to imply there is more noise. Using what you sayed in post #702 it should be an easy taskt to test at least noice floor on real music?

There is not one research paper on lossy encoding that uses test signals. All testing is done with music. To push the codec, "codec killer" test tracks are used but they are still not artificial test signals. My team developed such technology so you can't ask me to go along with a different metric of testing them against 100% of research and industry practice.

Just a thought, the MQA codec seem to be contradicting in its main function. It's compression (folding) scheme work best with music with low DR as demostrated by JA. Low DR music already have so much energy in the normal passband I wonder if ultrasonic would ever be revealed to us even listening to the original soundscape?

 

[PO3c]

I am blown away that amir does not seem concerned by MQA's blatant lies and deception.
...

Makes you wonder if other published work are biased aslo doesn't it? When he invite to test gear the most important piece in the puzzle he won't touch. And even repeat the marketing blurb without measurements to prove it advantageous for audiofiles.

Wait and see attitude are reason why Apple now possible are facing lawsuit in EU for how the different users on their buy in app policies. When lots of people warned about this was going to happen years ago Apple used their monopol exacly as expeded by lots of people.
https://www.bloomberg.com/news/arti...eu-antitrust-complaint-over-spotify-this-week

 

[mansr]

Here is my question (and I mean this respectfully): what is an appropriate test for MQA? Is there any music / signals that GoldenOne could have used that would appropriately test MQA? Or are you saying that this type of testing can't be performed at all?

The official MQA position appears to be that it shouldn't be tested, and any attempts to do so will not be tolerated. In a way, their reaction tells us more than the actual tests did.

 

[mansr]

As far as we understand, there is literally no place to put the ultrasonic information - the data from the original higher sample rate - on an MQA-CD because the data on the CD is 16-bit, not 24-bit. It would seem that an MQA CD either stuffs a very small amount of lossy encoded ultrasonics in the 14th, 15th, and 16th bits, or else it simply uses those bits to encode "authentication" information and the instruction/trigger to the MQA-compatible playback equipment to employ the MQA "apodizing" digital reconstruction filter upon playback.

In this respect, MQA CDs would seem to be even more fraudulent that MQA high-res digital/streaming files, as the MQA CD packaging routinely contains printed statements about "352.8kHz" resolution/sample rates, which (if you'll excuse the contradiction of trying to talk about degrees of an absolute thing like impossibility) is even more impossible than the resolution/sample-rate claims made for digital MQA files.

The infinite improbability drive is obsolete. Behold the infinite impossibility drive.

 

[voodooless]

I wonder if ultrasonic would ever be revealed to us even listening to the original soundscape?

I just checked one of those L2 records that you can download: "Arnesen: MAGNIFICAT 4. Et misericordia". Checked the part where there were the most ultrasonics. Already at 15 kHz, they were down 96 dB, at 24 kHz 127 dB down. This with the 96 kHz version. So I thought, let's see the 352 kHz version.. surely there must be some left? Ah, look: We can see some noise shaping of the ADC, from about 50 kHz to the end we see a rising spectrum of noise going from -120 dB to about -72. between 28 and 52 kHz, there is simply nothing.

Well, another file then? Let's try "Finzi: Come Away, Death". They didn't even bother with the 44.1 kHz file here, so there must be something good? The quick view of the spectrum shown once again the same picture, ultrasonice way below 100 dB. So I specifically selected a part where I saw a clear line in the ultrasonics all the way up to 40 kHz. Guess what? It still showed a peak of- 90 dB and the rest below -100dB.

And this is classical music mind you, the purest of the purest recordings.

So I wonder, what does the equal loudness curve look like for ultrasonics?

 

[voodooless]

Stereophile tests amps with square waves.
Normal, FLAC files can store them.

Hold it! PCM files cannot store square waves! Square files have an infinite spectrum, so cannot be stored in a finite bandwidth signal. You can approximate them for sure, but not "losslessly" store them in an audio file.

 

[mansr]

Regarding the pending thread closure, we know that MQA in the past have pressured Chris Connaker to shut down critical discussions, which to his credit he refused to do. Makes me wonder if a similar request has been made of ASR.

 

[AdamG]

Regarding the pending thread closure, we know that MQA in the past have pressured Chris Connaker to shut down critical discussions, which to his credit he refused to do. Makes me wonder if a similar request has been made of ASR.

Negative. No such request was made nor would it be honored.

 

[tw99]

@AdamG247 I hope that if this thread gets closed, then there won't be any problem with opening another one, or reopening this, if new information comes to light ?

 

[jensgk]

Negative. No such request was made nor would it be honored.

So why close the discussion of MQA.
It will only fuel alternative explanations as to why MQA discussions on ASR are not welcome.
The "Topping L30 Headphone Amplifier Review" thread currently has 227 pages and over 4500 replies, maybe that subject is also outdebated?

 

[restorer-john]

So why close the discussion of MQA.

What discussion was closed on MQA? And when by whom?

 

[jensgk]

What discussion was closed on MQA? And when by whom?

This thread. As I understand it, other threads were closed, because this thread existed.

 

[snowsurfer]

Negative. No such request was made nor would it be honored.

Several key issues on MQA raised in this thread have not been answered, it makes absolutely no sense to close the thread then, unless we're saving valuable bytes on the server for a rainy day. Even if part of the thread is somwewhat circular, what's the harm it's doing?

 

[snowsurfer]

What discussion was closed on MQA? And when by whom?

Mods announced that this thread would be closed today.

 

[Mnyb]

If the OP has more to add to his investigation ? where would he put it . There where test files more to mqa spec stopped by mqa , maybe op manage to get them in somehow later

 

[restorer-john]

Mods announced that this thread would be closed today.

I highly doubt that.

This thread has been most interesting, highly engaging (1896 posts and counting) and nobody in their right mind would consider it worthy of shutting down.

 

[bambadoo]

That would not be very smart. New threads will open. Better to leave it in one existing thread.

 

[bboris77]

Notice to all Thread participants: This tread has caused significant and unending arguments and circular logic. Beating a dead horse comes to mind. So, it is my decision to close this thread to further comment tomorrow afternoon. Get in your last words now. Please try to be brief

Don’t mean to be difficult, but if circular logic and unending arguments is the reason for closing this thread, you may as well close all of ASR and any other audio enthusiast forum for that matter. Quite often these discussions, however painful they are, can lead to a better understanding of the subject at hand and perhaps even progress in the field of audio reproduction.

Artificially putting an and to this discussion will just cause a bunch of new MQA threads to pop up. Why try to dampen the enthusiasm that this community has shown in discussing this topic?

I can see that at one point it got a bit off topic when people started questioning @amirm and his views on MQA. Surely this type of arguing can be reined in and kept civilized, rather than just shutting down the whole thing. In conclusion, shutting down such a popular thread will just end up feeding the conspiracies about ASR not being the place that people thought it was.

 

[SoundAndMotion]

I highly doubt that.

This thread has been most interesting, highly engaging (1896 posts and counting) and nobody in their right mind would consider it worthy of shutting down.

I hope not, but:

Notice to all Thread participants: This tread has caused significant and unending arguments and circular logic. Beating a dead horse comes to mind. So, it is my decision to close this thread to further comment tomorrow afternoon. Get in your last words now. Please try to be brief

 

[snowsurfer]

I hope not, but:

Thanks, I'm not on my PC right now and it's a hassle to look for it on mobile. That's the post I was referring to indeed.