Another major look at MQA by another pro.

[labjr]

3 minutes ago, Don Hills said:

 

The thing that worries many people is that if MQA becomes "the standard", you won't be able to avoid using it.

 

Yeah that would suck.

[esldude]

28 minutes ago, PeterV said:

snip...

It would be an invention of an even higher degree if MQA would just require an upsampling and filter protocol for reconstructing the original sound, wouldn't it..?

No. 

[PeterV]

Nobody over here knows how the MQA encoding and decoding process really works. The funny thing is that everyone is against it at some pages on CA and I doubt they have large doubts they ever auditioned it. With these reversed engineering attempts, some parts of the encoding are used, but not in full.  https://www.stereophile.com/content/mqa-questions-and-answers-udio-origami-or-folding-questions

[Fokus]

2 minutes ago, PeterV said:

Nobody over here knows how the MQA encoding and decoding process really works.

 

We know a lot, including the fundamental principles at the base of every aspect of this trickery.

 

As Mansr mentioned before: this contrary to you, who does not seem to know/understand a lot of this.

 

[mansr]

4 minutes ago, PeterV said:

Nobody over here knows how the MQA encoding and decoding process really works.

I know how the decoder works, and if you'd bothered to read my posts, so would you.

[Shadders]

18 minutes ago, PeterV said:

Nobody over here knows how the MQA encoding and decoding process really works. The funny thing is that everyone is against it at some pages on CA and I doubt they have large doubts they ever auditioned it. With these reversed engineering attempts, some parts of the encoding are used, but not in full.  https://www.stereophile.com/content/mqa-questions-and-answers-udio-origami-or-folding-questions

Hi,

Specifically "Nobody over here knows how the MQA encoding and decoding process really works."

What we do know, is that the actual 24bit sample is dithered down to 17bits, BUT is stated to recreate near 24bit sound through its process.

The filter applied to reconstruct is one of 32.

So we are not obtaining an accurate audio sequence, but something that is made to sound nice, or we are told is more accurate (but how can that be if we drop 7 bits from the sample - simple analogy).

You might as well process the file and add even order harmonics to make it sound nicer.

MQA is an effects processor, that is all. (my simplistic interpretation)

Regards,

Shadders.

[Fokus]

28 minutes ago, Shadders said:

What we do know, is ...

 

Your knowledge is also still lacking...

 

Apart from the DRM, A(uthentication), and the let's-obsolete-all-and-revive-the-market aspects MQA is a scheme that passes a 2x/4x/8x recording through a 1x channel, without using orthodox, steep AA and AI filters. MQA claims steep filters are evil, and so it invites alias/image distortion plus increased noise in a trade to remove the filters.

[PeterV]

Well, I disagree, the encoding and decoding are much more sophisticated than what is speculated, but please proceed to post on MQA and how it might work. It's all advertising in favour of MQA and I'm fine with that. I would be much more interested in measurements in the Time Domain and how both impulse response and time-smear is effectively being decreased. But so far, the encapsulation seems to be contributing positively to all re-engineering efforts and reconstruction efforts.

 

[Shadders]

2 minutes ago, Fokus said:

 

Your knowledge is also still lacking...

 

Apart from the DRM, A(uthentication), and the let's-obsolete-all-and-revive-the-market aspects MQA is a scheme that passes a 2x/4x/8x recording through a 1x channel, without using orthodox, steep AA and AI filters. MQA claims steep filters are evil, and so it invites alias/image distortion plus increased noise in a trade to remove the filters.

Hi,

I did not write a comprehensive review of MQA, but based it on the reference from :

https://benchmarkmedia.com/blogs/application_notes/163302855-is-mqa-doa

regarding the dropping 7 bits, and for the near 24bit reconstruction from the CA interview with Bob Stuart.

So the lack of knowledge is to keep the statement a minimum - i know some aspects of what you have written, such as the spread spectrum technique to encode the higher frequencies, but i do not know all the details.

Regards,

Shadders.

[mansr]

27 minutes ago, PeterV said:

Well, I disagree, the encoding and decoding are much more sophisticated than what is speculated

It's not speculation.

[soxr]

4 hours ago, PeterV said:

Although I am convinced that true MQA decoding will always need a decoder for full end-to-end delivery of the studio sound, this experiment is 'nice to know' but still not the real thing...;-)

 

PeterV clearly did not fully understand the article or just highlights those parts that confirm his bias.

MQA is not the studio sound. PeterV does not understand the typical studio workflow, and the fact that MQA is not encoded in the studio but in a remote MQA facility.

https://www.gearslutz.com/board/12717728-post1066.html

 

Quote

1) We send 176.4k 24-bit files and receive the 44k 16-bit encoded files. If our source is other than 176.4k (up to 192k) we use Weiss SaRaCon to transcode to 176.4 first. This is only for the MQA-CD release format.

2) My understanding is there are a number of parameters that affect the final sound which will be made accessible in a future mastering tool kit.

3) In our case, we monitor with a Mytek Brooklyn and a Mytek Manhattan II, both MQA enabled.

4) Not sure, authentication is still handled on the MQA server side.

5) Yes, we have approval rights, though MQA's engineers have done a very good job so far in tweaking and evaluating on their side before sending the encodes back to us. We have been happy with the results.

6) There is talk of a complete set of mastering tools to be rolled out to enable all this to be done in the mastering room.

 

2) proves studio engineers don't have any control over MQA encodes (yet), hence MQA is not part of the mastering process

4) no engineer signs the MQA file

5) proves MQA is not part of the mastering by the studio, but by an MQA engineer who decides on the parameters such as which anti post-ringing to use for the renderer stage

Furthermore MQA has been authenticated by real studio engineers such as Brian Lucey, not to be the studio sound:

https://www.gearslutz.com/board/12548751-post460.html

 

 

Quote

MQA is, in all of my tests so far, brighter and thinner with more distortion, and a sense of excitement (remember Aphex?) and even volume from the artifacts. Sure many lay people will be fooled. I don't like to see pros fooled, but oh well, that's why I'm busy I suppose and they're posturing next to a new product so I'm free to tell the truth here.

 

[soxr]

3 hours ago, PeterV said:

Well, I disagree, the encoding and decoding are much more sophisticated than what is speculated, but please proceed to post on MQA and how it might work. It's all advertising in favour of MQA and I'm fine with that. I would be much more interested in measurements in the Time Domain and how both impulse response and time-smear is effectively being decreased. But so far, the encapsulation seems to be contributing positively to all re-engineering efforts and reconstruction efforts.

 

 

Why didn't you ask Bob Stuart to provide test tones? You are directly connected to Bob and MQA on social media.

You are always begging for proof and always going back to your fallback argument of time domain and impulse response, while these measurements have already been proven by independent research. Impulse responses have been plotted and dumped by mansr and archimago.

It's clear that you don't understand archimago's measurements or ignore them, or play dumb to stall or stretch the discussion and always fallback to your same argument.

 

[labjr]

I haven't heard MQA fully decoded, but I still feel it should be defeated based on principle alone. No one entity should be trying to monopolize the market and collect revenue from every facet. They've contradicted themselves with their own statements about "Crown Jewels". Hiding details even from manufacturers that include MQA in their products is suspicious. Definitely motivation for those who are debunking MQA. Maybe it should be on Mythbusters!

[mcgillroy]

Oh PeteV got deployed again. Seems like someone at MQA feels the impacts coming closer.

 

There's nothing like boots on the ground spreading FUD, especially if your grunt is a jolly fellow happily absorbing the incoming and keeping everybody busy.

 

 

 

 

[PeterV]

Well soxr and others trying to understand what MQA really is doing, I am unfortunately just able to listen to what fully enfolded MQA does on my system at home, but also on a true Top-End system with MSBtechnology Reference DAC This was for me the ultimate listening test, since if even this DAC is improving it's soundquality, it is clear that the format is not a hoax or marketing scam. Yes, in my persistence to understand how it works, I would like to see measurable proof as well, especially in the Time Domain. My contacts with Bob Stuart are just via Facebook, where I am connected with him and I did send him and the MQA team questions. I must admit that I did not get any further than expressing myself to them that a Time Domain measurement would be of interest for all of us. Would it be possible to achieve this? Well, if MQA would do such measurements themselves, no one will believe it I suppose. So it is an interesting task to find a technique where the audible time-smear reduction of MQA can be verified with objective measurements in Air I would say.  Nowadays much DSP software is available like Trinnov, Dirac, DEQX and others which are manipulating loudspeaker performance in the Time & Frequency domain heavily.. I am not technical, I do not care about non-decoded MQA measurements in the Digital Domain. I am only interested in the end result and why my ears ( and others) seem to like it.. So sorry soxr, no test signals available, but there are so many MQA albums on the market, there should at least be one of them which contains a relatively isolated single tone.. Just use that and do A/B comparison.. or is this an impossible route?  And to labjr...do you realise that during the introduction of the CD we also have been 'seized' by Sony and Philips..?  What is your problem with a sophisticated, but proprietary technology which is improving the sound. Just take tome and listen to it first..I am convinced you will understand why I am so positive and have the urge to express myself especially to this and other pre-occupied and very negative persons and groups. It will be interesting to know if Archimago ever really listened to a high-end MQA system. A blind A/B audition, combined with Time-Smear comparison measurements in Air would be the best way to understand really what MQA is all about.

[mcgillroy]

Hey Pete, nice attempt on surpressive fire, lots of ammo in your discursive machine gun.

 

Unfortunately all duds.

 

Come back if you have a real bullet. And learned to aim.

 

 

[PeterV]

I am just trying to understand what I personally hear and experience om my own way mcgillroy.  I am currently collecting lots of stuff and publications and diving and reading MQA patents etc.  This one I just found and added to my 'library' This work investigates the temporal resolution of human hearing through its discrimination of the time constant of low-pass filtering applied to a periodic signal. While restricting the bandwidth affects both the amplitude spectrum and temporal definition of the signal, the direct amplitude changes in this experiment fall below their just noticeable differences. The discrimination therefore seems to be sensitive to phase in addition to spectral amplitude differences. An upperbound of τ ≈ 5 μs was obtained for the threshold time constant, showing that human temporal resolution extends down to time scales shorter than found in the past  http://boson.physics.sc.edu/~kunchur/papers/Temporal-resolution-by-bandwidth-restriction--Kunchur.pdf

[PeterV]

This stuff is also interesting:   https://phys.org/news/2013-02-human-fourier-uncertainty-principle.html

 

[Fokus]

6 minutes ago, PeterV said:

This was for me the ultimate listening test, since if even this DAC is improving it's soundquality, it is clear that the format is not a hoax or marketing scam.

 

You are aware that at least some MQA files have been derived from totally different masters, perhaps even different mixes, than the standard releases that are out there?

 

You are aware that undecoded MQA contains the hidden signal crud that contaminates the base signal, potentially in an audible way?

 

6 minutes ago, PeterV said:

 expressing myself to them that a Time Domain measurement would be of interest for all of us. Would it be possible to achieve this? Well, if MQA would do such measurements themselves, no one will believe it I suppose. So it is an interesting task to find a technique where the audible time-smear reduction of MQA can be verified with objective measurements in Air

 

What do you need measurements for? You can derive a decent guess of the overall impulse response of an MQA chain quite easily with the information that is now publicly available. Assuming that you start from a 8x recording (DXD), concatenate the IRs of the ADC and two of the leaky filters Mansr/Archimago have published. That's about it.

 

You are aware that looking at IRs of systems with a bandwidth > 20kHz and imagining that a nice Dirac impulse is the holy grail has not much to do with actual music, nor with how the human auditory system works?

 

Let's do a thought experiment. Take a 44.1k ADC and DAC. Remove the anti-aliasing and the anti-imaging filters. Put them back to back.  Feed in a nice, perfect impulse. Observe the output and swoon. Or drool.

 

Now feed it some music, and listen ...

 

6 minutes ago, PeterV said:

Nowadays much DSP software is available like Trinnov, Dirac, DEQX and others which are manipulating loudspeaker performance in the Time & Frequency domain heavily..

 

Yes. And ironically, if MQA have their way all these systems are obsolete, and MQA have to be paid dues (and royalties) in order for these systems to function again.

 

But yes, frequency/time correction is done to speaker systems. With great effect. But this is smack in the middle of the audible band, with sub-systems with non-linear frequency response and with significant inter-driver delays.

 

6 minutes ago, PeterV said:

 I am only interested in the end result and why my ears ( and others) seem to like it..

 

No. You are only interested in whatever confirms your notion that MQA is better, and that this is because of something you call time smear (and which you do not understand, at all).

 

6 minutes ago, PeterV said:

there should at least be one of them which contains a relatively isolated single tone.. Just use that and do A/B comparison.. or is this an impossible route?

 

You want people to listen to one note and conclude from this that MQA is better? Or do you want people to look at the trace of a single note???? If the latter: you won't see ringing or blurring. Really.

 

6 minutes ago, PeterV said:

.do you realise that during the introduction of the CD we also have been 'seized' by Sony and Philips..?  What is your problem with a sophisticated, but proprietary technology which is improving the sound.

 

CD was entirely new, building on nothing that came before. As such it was simply necessary for customers to buy into it totally.

MQA is a flavour of PCM, behind locked doors, threatening to obsolete open PCM and all of its tools (i.e. software and hardware, see my remark on DSP above). And this for no use. Even if it really sounded better, it would be of no use.

 

6 minutes ago, PeterV said:

Just take tome and listen to it first..I am convinced you will understand why I am so positive and have the urge to express myself especially to this and other pre-occupied and very negative persons and groups.

 

Oh, I did. I do have an MQA DAC. I do have listened to it. In many cases the MQA was just as good/bad as the original. In some cases the MQA was better, but clearly from a different master, so the gains would pass equally well through a non-MQA chain.

 

6 minutes ago, PeterV said:

 the best way to understand really what MQA is all about.

 

I know perfectly well what MQA is about.

 

[Shadders]

35 minutes ago, Fokus said:

 

You are aware that at least some MQA files have been derived from totally different masters, perhaps even different mixes, than the standard releases that are out there?

 

You are aware that undecoded MQA contains the hidden signal crud that contaminates the base signal, potentially in an audible way?

 

 

What do you need measurements for? You can derive a decent guess of the overall impulse response of an MQA chain quite easily with the information that is now publicly available. Assuming that you start from a 8x recording (DXD), concatenate the IRs of the ADC and two of the leaky filters Mansr/Archimago have published. That's about it.

 

You are aware that looking at IRs of systems with a bandwidth > 20kHz and imagining that a nice Dirac impulse is the holy grail has not much to do with actual music, nor with how the human auditory system works?

 

Let's do a thought experiment. Take a 44.1k ADC and DAC. Remove the anti-aliasing and the anti-imaging filters. Put them back to back.  Feed in a nice, perfect impulse. Observe the output and swoon. Or drool.

 

Now feed it some music, and listen ...

 

 

Yes. And ironically, if MQA have their way all these systems are obsolete, and MQA have to be paid dues (and royalties) in order for these systems to function again.

 

But yes, frequency/time correction is done to speaker systems. With great effect. But this is smack in the middle of the audible band, with sub-systems with non-linear frequency response and with significant inter-driver delays.

 

 

No. You are only interested in whatever confirms your notion that MQA is better, and that this is because of something you call time smear (and which you do not understand, at all).

 

 

You want people to listen to one note and conclude from this that MQA is better? Or do you want people to look at the trace of a single note???? If the latter: you won't see ringing or blurring. Really.

 

 

CD was entirely new, building on nothing that came before. As such it was simply necessary for customers to buy into it totally.

MQA is a flavour of PCM, behind locked doors, threatening to obsolete open PCM and all of its tools (i.e. software and hardware, see my remark on DSP above). And this for no use. Even if it really sounded better, it would be of no use.

 

 

Oh, I did. I do have an MQA DAC. I do have listened to it. In many cases the MQA was just as good/bad as the original. In some cases the MQA was better, but clearly from a different master, so the gains would pass equally well through a non-MQA chain.

 

 

I know perfectly well what MQA is about.

 

Hi,

Well Done.

Regards,

Shadders.

[Miska]

On 7/21/2017 at 2:52 AM, mansr said:

This means we're looking at an AVR-like device incorporating both MQA decoder and DSP stage. Such a device can of course be quite capable, but forget about tinkering with HQPlayer or custom solutions. The other option is software decoding. This produces a 96/24 PCM stream to which DSP can be reasonably applied.

 

To overcome this for Tidal MQA, Spotify, etc I took the route to make HQPlayer (Embedded) capable of taking realtime audio inputs. So now I can play Tidal with the Tidal application, with software decoding and it doesn't have slightest idea that the decoded output is going through HQPlayer's DSP... Same goes for Spotify.  Another reason for the input capability though was to enable same digital room correction for analog sources like vinyl and digital sources like old CD spinners. And people don't have to keep complaining about my GUI either...

 

But having such closed technical solution as MQA that has bunch of features trying to enforce their technical choices for oversampling digital filters and such is bad overall and severely hampers innovation possibilities of software and hardware developers. Such solution can never be called "standard" since it is not open and not ratified by any established standards body and it better not become "de facto". Content shouldn't be kept hostage.

 

[PeterSt]

38 minutes ago, Fokus said:

You are aware that at least some MQA files have been derived from totally different masters, perhaps even different mixes, than the standard releases that are out there?

 

And would you be able to accept from someone like me that this is exactly the reason I might (!) like MQA for the better ?

I hate all what's tagged "remaster" just because it's done for the modern world, wherever that is. But I did not find any MQA album yet which is heavily compressed. The contrary.

 

Btw, I am saying all along that the masters used for MQA are different. And I see it as a virtue.

 

PS: On the sound of MQA itself I am neutral. These days I play all MQA what's within the repertoire I like, and at least I can play the whole albums. That tells a LOT.

 

PPS: MQA does not work out because it is DOA already. Watch for the day you're reminded about this PPS.

[Shadders]

1 hour ago, PeterV said:

I am only interested in the end result and why my ears ( and others) seem to like it.

Hi,

I think this is a key aspect.

MQA Ltd have designed a process to manipulate an audio file that sounds good to many people.

Many people are not technical, and it would be similar to one person stating that another cannot like valve amplifiers, as they measure worse than the ultimate (a bit of wire with gain - amplifier). Yet despite this, people still buy valve amplifiers.

Regards,

Shadders.

[PeterSt]

6 minutes ago, soxr said:

PeterV is inviting MQA resellers on social media into secret closed groups.

 

I'm glad I'm not a woman or otherwise I would use FB.

[Fokus]

17 minutes ago, soxr said:

I am here because we found an open source way to handle MQA files

 

What?

 

You take undecoded MQA and upsample it with a MP filter. That's not 'handling MQA files'.