Another major look at MQA by another pro.

[PeterV]

7 minutes ago, Charles Hansen said:

 

You've already answered your own question. Digital filters do make a difference in the sound quality of a D/A converter (as does almost everything to one degree or another - try replacing the AC power line fuse with one of the "super fuses"), but I would rank them in a fairly distant 6th or 7th place compared to other factors such as the analog circuitry and power supplies. You've already said that the DCC master of The Doors sounded quite a bit better than the MQA version, so clearly better mastering makes a much greater difference than digital filters.

 

I am not convinced it is just the digital filter aspect with regard to MQA..  It seems to me a nice 'add-on' function which can work effectively on Mastertapes with regard to the deblurring functionality. If the technology is used on the best available Master out there. In potential there might be room for more MQA masters.. why not?  DDC-MQA  or MFSL-MQA versions beside others..

[Charles Hansen]

2 hours ago, PeterSt said:

 

That should be a typo.

 

Hi Peter,

I can only surmise that there is some language barrier between Dutch to English and Flemish to English.

 

Soxr is 100% correct. The very first step in MQA processing is to re-sample the original high-res file at a 96kHz sample rate. Therefore the maximum frequency that can be reproduced is 48kHz and everything above that on the final playback (after the first "unfolding") is simply non-music related aliasing artifacts. This is particularly true when the original file was a quad-rate (176 or 192kHz) or an octal-rate (352 or 384kHz). Upsampling can never restore the missing high frequencies (above 48kHz) and the "leaky" MQA filters create non-harmonically related ultrasonic noise in the general frequency range that the quad- and octal-rate files had (at least some) musically related information.

 

Hope this helps.

 

[rickca]

32 minutes ago, PeterSt said:

So, let's respect that ? 

No disrespect intended.  Charles is making a strong case against adoption of MQA in this thread, so I expected a response with some conviction.  It's fine to answer a question by saying 'I'm not ready to talk about that yet'.

[Charles Hansen]

4 minutes ago, PeterV said:

 

I am not convinced it is just the digital filter aspect with regard to MQA..  It seems to me a nice 'add-on' function which can work effectively on Mastertapes with regard to the deblurring functionality. If the technology is used on the best available Master out there. In potential there might be room for more MQA masters.. why not?  DDC-MQA  or MFSL-MQA versions beside others..

 

Whatever you say, Peter. Maybe you should start your own re-issue company, selling MQA versions of existing recordings.

[PeterV]

9 minutes ago, Charles Hansen said:

 

Hi Peter,

I can only surmise that there is some language barrier between Dutch to English and Flemish to English.

 

Soxr is 100% correct. The very first step in MQA processing is to re-sample the original high-res file at a 96kHz sample rate. Therefore the maximum frequency that can be reproduced is 48kHz and everything above that on the final playback (after the first "unfolding") is simply non-music related aliasing artifacts. This is particularly true when the original file was a quad-rate (176 or 192kHz) or an octal-rate (352 or 384kHz). Upsampling can never restore the missing high frequencies (above 48kHz) and the "leaky" MQA filters create non-harmonically related ultrasonic noise in the general frequency range that the quad- and octal-rate files had (at least some) musically related information.

 

Hope this helps.

 

 

Well, your explanation does not clarify what 2L says: "MQA uses a process called ‘music origami’ to ‘fold’ a high-sample-rate signal down to a smaller, lower-data-rate file which can be played back without a decoder. 2L-048 is folded once to 48 kHz 24 bit; 2L-120 has no folds; the others are folded three times from 352.8 to 44.1 kHz 24 bit. An MQA decoder will restore the original recording and ‘unfold’ it to optimally match its D/A converter. So, for example, on a mobile device, 2L-111 (which is from DXD) can be unwrapped to 44.1, 88.2 or 176.4 kHz whereas a higher-performance DAC can unfold all the way to 352.8 kHz.'   

[PeterV]

10 minutes ago, Charles Hansen said:

 

Whatever you say, Peter. Maybe you should start your own re-issue company, selling MQA versions of existing recordings.

 

I will probably not have enough money to pay the licence fee to MQA.. :-)

 

[mansr]

7 minutes ago, PeterV said:

Well, your explanation does not clarify what 2L says: "MQA uses a process called ‘music origami’ to ‘fold’ a high-sample-rate signal down to a smaller, lower-data-rate file which can be played back without a decoder. 2L-048 is folded once to 48 kHz 24 bit; 2L-120 has no folds; the others are folded three times from 352.8 to 44.1 kHz 24 bit. An MQA decoder will restore the original recording and ‘unfold’ it to optimally match its D/A converter. So, for example, on a mobile device, 2L-111 (which is from DXD) can be unwrapped to 44.1, 88.2 or 176.4 kHz whereas a higher-performance DAC can unfold all the way to 352.8 kHz.'   

That quote has little to do with what actually happens in an MQA decoder.

[Fitzcaraldo215]

41 minutes ago, PeterSt said:

What is time smear ?

https://www.stereophile.com/content/mqa-questions-and-answers-some-real-world-comparisons

 

See figure 8, which compares time response at 44k, 192k, MQA and acoustically in air at various distances.  Note that it is about the precision of reproduction of the steepness of the impulse, not about the accuracy of placing the center of the impulse correctly in time.  The rest of that article is worth a read, if you have not already done so.

[PeterSt]

26 minutes ago, Charles Hansen said:

Hope this helps.

 

No. Except that our English should improve somewhat.

If now you think too that I said anywhere that 50KHz of frequency can come from a 96KHz sampling rate, then I politely ask you too : quote that please.

I plainly did not say that.

It couldn't be true either. Haha.

[firedog]

1 hour ago, rickca said:

@Charles Hansen I guess you don't want to answer this question since you've ignored it twice.  

Sometimes the answer is obvious, no?

Why keep asking. Use your brain.

[Digital Assassin]

31 minutes ago, PeterV said:

 

I am not convinced it is just the digital filter aspect with regard to MQA..  It seems to me a nice 'add-on' function which can work effectively on Mastertapes with regard to the deblurring functionality. If the technology is used on the best available Master out there. In potential there might be room for more MQA masters.. why not?  DDC-MQA  or MFSL-MQA versions beside others..

LOL!!!!! Thanks for the laugh!

[PeterSt]

10 minutes ago, Fitzcaraldo215 said:

https://www.stereophile.com/content/mqa-questions-and-answers-some-real-world-comparisons

 

See figure 8, which compares time response at 44k, 192k, MQA and acoustically in air at various distances.  Note that it is about the precision of reproduction of the steepness of the impulse, not about the accuracy of placing the center of the impulse correctly in time.  The rest of that article is worth a read, if you have not already done so.

 

Thank you Fitz. I was merely teasing PeterV because I am under the impression that more and more is made up because elsewhere someone tells something and he's not an MQA representative. It is getting tiring a little, don't you agree ?

 

Something quite else is that it is the the highest time that MQA jumps in somewhere, which would be everywhere at the same time by now. This strategy of remaining silent does not work out. Hear ya ?

[rickca]

6 minutes ago, mansr said:

That quote has little to do with what actually happens in an MQA decoder.

I get the impression that the current MQA implementation is a very watered down version of the original theory.  Maybe that's why there is such an apparent disconnect between Bob Stewart's Q&A and available products.

[PeterSt]

23 minutes ago, PeterV said:

Well, your explanation does not clarify what 2L says: "MQA uses a process called ‘music origami’ to ‘fold’ a high-sample-rate signal down to a smaller, lower-data-rate file which can be played back without a decoder. 2L-048 is folded once to 48 kHz 24 bit; 2L-120 has no folds; the others are folded three times from 352.8 to 44.1 kHz 24 bit.

 

Peter, why don't you invest some time in understanding better what is going on from all the angles present. There is no such thing as "2L says" = the truth. They too repeat what MQA told them. Hey, I should do that too, but ...

[PeterSt]

4 minutes ago, rickca said:

I get the impression that the current MQA implementation is a very watered down version of the original theory.

 

Or Story.

Or maybe MQA is going to be better than the perceived theory. No, told theory. Or was it a story ? 

[Digital Assassin]

5 hours ago, PeterV said:

 

So how do you regard this statement by Peter McGrath, who last year told this on Audiostream and  this year at LAAS demonstrated MQA with his own recordings: 

 

"MQA closes the gap between what I hear from the mic feed and the storage medium chosen to present it" is another of my favorite quotes from Peter since recording engineers, and musicians as we are learning from Graham Nash's comments over on Stereophile, have heard things we haven't—namely the original context of the recording. Jon Iverson, who is also a recording engineer, has also commented that what he looks for in hi-fi is a sound as close to the mic feed as he can get. Interesting. I'll leave our conversation with Peter with one last quote, "This is of breathtakingly unbelievable significance."

 

http://www.soundstageglobal.com/index.php/shows-events/los-angeles-audio-show-2017-los-angeles-usa/712-laas-2017-a-different-kind-of-mqa-demo

 

To me these experiences by Peter McGrath are genuine, but I am an MQA  'believer'  :-)

Consider the fact that McGrath's recordings are rather dull, and basic, and that ANY sweetening will make them sound "better".

 

Also consider the fact he is using MQA to get his obscure recordings heard.

 

Also consider that Meridian has used Wilson speakers to demo MQA almost exclusively.

 

Try again.

[rickca]

18 minutes ago, firedog said:

Sometimes the answer is obvious, no?

Why keep asking. Use your brain.

Do you think the answer is obvious from Charles Hansen's response?  Is it the same obvious answer you concluded before?

https://www.computeraudiophile.com/forums/topic/34750-another-major-look-at-mqa-by-another-pro/?do=findComment&comment=706258

 

Charles is making a strong case against adoption of MQA.  So I found this confusing

https://www.computeraudiophile.com/forums/topic/31169-ayre-qx-5-is-now-mqa-compliant/

 

[rickca]

14 minutes ago, PeterSt said:

 

Or Story.

Or maybe MQA is going to be better than the perceived theory. No, told theory. Or was it a story ? 

I guess I was trying to be generous.

[Fokus]

On 8/12/2017 at 11:18 AM, PeterV said:

I just would like to understand how these arguments can be achieved..  How much time-smear does a DXD recording contain..? and when such a recording is played on a DXD capable DAC, how much is the Time-Smear in air ?  These are sinply fundamental questions to understand the importance of the presence or absence of Temporal Blur artefacts in music!

 

Start studying the sampling theorem, including its formal proof. Don't stop until you really get it.  Then look into DSP, and into AA and AI filters in particular. This done, have a look at the impulse responses of popular ADC and DAC chips. Ask yourself how relevant these are, considering the legal status of the stimulus. Look into the spectral distribution of typical music. Study the human auditory system. How does the basilar membrane react to a steep wavefront. How wide is an ERB in the upper octave of the ear response. What is the temporal implication of this?

 

once you have done this you can come here for any further questions. Until then COMMENT EDITED FOR PERSONAL ATTACK. - CC

 

[mansr]

1 minute ago, Fokus said:

Start studying the sampling theorem, including its formal proof. Don't stop until you really get it.  Then look into DSP, and into AA and AI filters in particular. This done, have a look at the impulse responses of popular ADC and DAC chips. Ask yourself how relevant these are, considering the legal status of the stimulus. Look into the spectral distribution of typical music. Study the human auditory system. How does the basilar membrane react to a steep wavefront. How wide is an ERB in the upper octave of the ear response. What is the temporal implication of this?

 

once you have done this you can come here for any further questions. Until then ... fuck off.

That should keep him busy a few years.

[Fokus]

1 hour ago, rickca said:

I get the impression that the current MQA implementation is a very watered down version of the original theory.  

 

Not really. It still matches the understanding I got early in 2015. The biggest delta is that apparently there is not much customisation of the render filters with respect of the actual DAC going on.

[Jud]

1 hour ago, Fokus said:

 

Not really. It still matches the understanding I got early in 2015. The biggest delta is that apparently there is not much customisation of the render filters with respect of the actual DAC going on.

 

Yep.

 

Just a suggestion: All indications are that PeterV will not be going away voluntarily.  Rather than fruitlessly imploring him to do so, why not simply stop conversing with him and let him talk to the air if he wishes?

[Digital Assassin]

2 minutes ago, Jud said:

 

Yep.

 

Just a suggestion: All indications are that PeterV will not be going away voluntarily.  Rather than fruitlessly imploring him to do so, why not simply stop conversing with him and let him talk to the air if he wishes?

Because folks can't help themselves in feeding the troll.

[soxr]

The Ignored Users is a nice feature here.
On facebook I did use the blocking function.

When people do not learn anything from the material presented, and always keep repeating the same old canned resources, it's time to no longer waste time on these users and ignore them. It's like a discussion with flat earthers: pointless.

Some years ago, when a forum would not have a block / ignore function, I would write some greasemonkey script that completely hides their posts from the topic. Worked well. At least this forum is more advanced and does not need that.

[mansr]

42 minutes ago, Jud said:

Rather than fruitlessly imploring him to do so, why not simply stop conversing with him and let him talk to the air if he wishes?

Because we all have to breathe that air.