MQA The Truth lies Somewhere in the Middle

[sls]

On 10/20/2018 at 3:49 PM, Lee Scoggins said:

 

MQA revenue won't be $48 million of course, they get a percentage of that.  The key for MQA is to get a revenue stream from most of the participants in the ecosystem.

 

Incorrect.

 

If you read the UK published accounts, page 2, the route to profitability is hardware revenues:

 

"With major streaming services expressing specific interest in adopting MQA, and subsequently initiating detailed

technical reviews, we remain confident that MQA content will become available across one of the larger, multi-

territory services and will drive the hardware royalty revenues necessary to achieve profitability and sustained

revenues."

 

Reinet, who have a controlling interest in MQA, also have a controlling interesting Meridian, which has been a financial basket-case for years. It is all about selling Meridian kit and royalties from hardware manufacturers for embedded MQA.

[John_Atkinson]

On 10/15/2018 at 5:45 PM, John_Atkinson said:

When I have a  spare minute, I will take a look at the difference between the channels of both files, which should reveal any truth in Mr. Carver's assertion.

 

Bob Carver claimed that the MQA files sent to writers had been processed with something like his Sonic Holography circuit. This circuit is basically a Blumlein "shuffler," which splits the stereo audio signal into its Sum and Difference components, applies gain and/or EQ to the Difference component, then recombines the Sum and Difference components into Left and Right signals.

So, if Carver's claim is correct, then examining the Difference between the two channels of an MQA file and the PCM original will reveal if any "shuffling" had been done.

I took 3 recordings for which I had both the originals and the MQA versions that I had used for my initial auditioning of MQA back in 2016 where I had found the MQA version to sound superior: a track from Keith Jarrett's Cologne Concert, a Debussy prelude, and one of my choral recordings with the Portland State Chamber Choir.

Extracting the difference information for the PCM originals was straightforward. For the MQA versions, I decoded the files with Roon feeding my PS Audio DAC and and digitized the PS Audio's analog out with an Ayre A/D converter operating at 24 bits and 192kHz sample rate. I adjusted the peak levels of the resultant files to match those of the original PCM files and extracted the channel difference information.

In all 3 cases, the channel-difference file of the MQA version had the same peak level as that of the original PCM file, as well as virtually identical spectra. So Bob Carver was wrong.

John Atkinson
Editor, Stereophile

[KeenObserver]

1 hour ago, John_Atkinson said:

 

Bob Carver claimed that the MQA files sent to writers had been processed with something like his Sonic Holography circuit. This circuit is basically a Blumlein "shuffler," which splits the stereo audio signal into its Sum and Difference components, applies gain and/or EQ to the Difference component, then recombines the Sum and Difference components into Left and Right signals.

So, if Carver's claim is correct, then examining the Difference between the two channels of an MQA file and the PCM original will reveal if any "shuffling" had been done.

I took 3 recordings for which I had both the originals and the MQA versions that I had used for my initial auditioning of MQA back in 2016 where I had found the MQA version to sound superior: a track from Keith Jarrett's Cologne Concert, a Debussy prelude, and one of my choral recordings with the Portland State Chamber Choir.

Extracting the difference information for the PCM originals was straightforward. For the MQA versions, I decoded the files with Roon feeding my PS Audio DAC and and digitized the PS Audio's analog out with an Ayre A/D converter operating at 24 bits and 192kHz sample rate. I adjusted the peak levels of the resultant files to match those of the original PCM files and extracted the channel difference information.

In all 3 cases, the channel-difference file of the MQA version had the same peak level as that of the original PCM file, as well as virtually identical spectra. So Bob Carver was wrong.

John Atkinson
Editor, Stereophile

 

Just for our edification, were you a proponent of the green marker back in the early days of CD?

[Miska]

1 hour ago, John_Atkinson said:

Extracting the difference information for the PCM originals was straightforward. For the MQA versions, I decoded the files with Roon feeding my PS Audio DAC and and digitized the PS Audio's analog out with an Ayre A/D converter operating at 24 bits and 192kHz sample rate. I adjusted the peak levels of the resultant files to match those of the original PCM files and extracted the channel difference information.

 

That doesn't sound straightforward at all. It really shouldn't be that difficult. And it is not, better make digital capture of the decode for comparisons.

 

Although I've done similar and the original hires PCM is clearly superior compared to the MQA version.

 

[psjug]

2 hours ago, John_Atkinson said:

In all 3 cases, the channel-difference file of the MQA version had the same peak level as that of the original PCM file, as well as virtually identical spectra. So Bob Carver was wrong.

John Atkinson
Editor, Stereophile

Thanks for doing that.  Have you had any communication with Bob Carver to know why he was so sure about the crosstalk cancellation?

[KeenObserver]

Once again I am listening to the non MQA version of Simon and Garfunkel's  Sound of Silence.

 

For your edification:

 

A Stereophile Recommended Accessory for the Last 18 Years: Recommended by John Atkinson, Sam Tellig and Robert Harley

The AudioPrism CD Stoplight (the green pen) is the original CD tweak. Just paint the edges of your CDs to greatly reduce disc read errors and reduce jitter while improving clarity and reducing glare. We have sold the CD Stoplight to thousands of customers in the last decade. This tweak really works and it's affordable and simple to use.

"This stuff works! The cost per disc of this tweak is almost zero...it offers a big bang for the buck and can be confidently recommended!" – John Atkinson, Stereophile

 

Doesn't surprise me that John Atkinson is one of the foremost proponents of MQA.

[fas42]

Just to be fair in this situation, the green pen treatment was a simple, physical aid to the reading of CDs, which reduced the electrical inteference caused by the circuitry "working harder" to extract a clean data stream - it falls in the same category of tweaks as, in the pure analogue side, mounting a turntable so vibrations in the room have less impact.

 

MQA is a remastering of the source to allow playback systems to do "a better job", by "compensating for shortcomings"; an analogue equivalent would be the Dynagroove pressings of LPs.

[Ralf11]

6 minutes ago, fas42 said:

Just to be fair in this situation, the green pen treatment was a simple, physical aid to the reading of CDs, which reduced the electrical inteference caused by the circuitry "working harder" to extract a clean data stream - it falls in the same category of tweaks as, in the pure analogue side, mounting a turntable so vibrations in the room have less impact.

 

 

Nope

[Miska]

5 minutes ago, fas42 said:

MQA is a remastering of the source to allow playback systems to do "a better job", by "compensating for shortcomings"; an analogue equivalent would be the Dynagroove pressings of LPs.

 

How do those horribly bad upsampling filters do "a better job" at anything?

 

Why they don't just "fix" the source and put it in a standard FLAC, without all the origami folding and authentication crap?

 

Now it is some crazy junk dump yard of various technological gimmicks mangling the content.

[fas42]

23 minutes ago, Ralf11 said:

 

Nope

 

You appear not to have discovered that most audio components are under engineered with regard to resistance to vibrational factors - which is why a plethora of tweaks exist to mitigate these influences.

 

One can buy a car from a showroom which does everything "pretty well" - the limits are quickly found when the driver decides to drive "enthusiastically" - hence the huge aftermarket for specialist items to deal with this ... audio is no different.

[fas42]

27 minutes ago, Miska said:

 

How do those horribly bad upsampling filters do "a better job" at anything?

 

Why they don't just "fix" the source and put it in a standard FLAC, without all the origami folding and authentication crap?

 

Now it is some crazy junk dump yard of various technological gimmicks mangling the content.

 

That's why I put it in quotes ... it "helps" some but not others.

 

Down the track, what it does will highly likely be fully revealed, one way or the other, and it will be available for anyone to suck and see - just another bit of DSP, as a software app, to fiddle with your recordings, and "make them better".

[Miska]

8 minutes ago, fas42 said:

Down the track, what it does will highly likely be fully revealed, one way or the other, and it will be available for anyone to suck and see - just another bit of DSP, as a software app, to fiddle with your recordings, and "make them better".

 

That's how it should have been, IMO, since the beginning. And not messing with the entire content chain. I would have zero problems with it such way.

 

[KeenObserver]

1 hour ago, fas42 said:

Just to be fair in this situation, the green pen treatment was a simple, physical aid to the reading of CDs, which reduced the electrical inteference caused by the circuitry "working harder" to extract a clean data stream - it falls in the same category of tweaks as, in the pure analogue side, mounting a turntable so vibrations in the room have less impact.

 

MQA is a remastering of the source to allow playback systems to do "a better job", by "compensating for shortcomings"; an analogue equivalent would be the Dynagroove pressings of LPs.

 

Did you, by chance, study under Professor Irwin Corey?

 

Nice deflection, though.

[Ralf11]

37 minutes ago, fas42 said:

most audio components are under engineered with regard to resistance to vibrational factors - which is why a plethora of tweaks exist to mitigate these influences.

 

One can buy a car from a showroom which does everything "pretty well" - the limits are quickly found when the driver decides to drive "enthusiastically" - hence the huge aftermarket for specialist items to deal with this ... audio is no different.

 

Nope

[fas42]

"Nope" is a very powerful argument - I bow down before the vigour and strength of such a rebuttal ...

[fas42]

Also known as; when one decides to go tribal, the "truth" is usually the least significant factor in the discussion ...

[John_Atkinson]

14 hours ago, Miska said:

15 hours ago, John_Atkinson said:

Extracting the difference information for the PCM originals was straightforward.

 

That doesn't sound straightforward at all.

 

By straightforward, I meant that it was conceptually simple: load the file into a DAW; subtract the right channel from the left channel, save the resultant mono information; and analyze those data for spectrum and peak and average levels.

 

14 hours ago, Miska said:

It really shouldn't be that difficult. And it is not, better make digital capture of the decode for comparisons.

 

That is what I did for the MQA-encoded files, matching the peak levels of the digital capture of the MQA playback to those of the original files. The MQA files were all unfolded to 2Fs so by running the A/D converter at 4Fs, its own behavior would be out-of-band. And when those data were analyzed, the differences between the channels were the same as those of the original PCM files, meaning that Bob Carver's unsupported assertion that MQA encoding includes crosstalk cancellation - he didn't perform difference tests - was wrong.

 

John Atkinson

Editor, Stereophile 

[mansr]

10 minutes ago, John_Atkinson said:

digital capture of the MQA playback

You said you did an analogue capture.

[John_Atkinson]

1 minute ago, mansr said:

You said you did an analogue capture.

 

By "digital" I mean that the decoded MQA analog signals were redigitized for analysis.

 

MQA files played with Roon server -> network connection -> PS Audio DAC with volume control set to its maximum, thus bypassed -> analog output -> Ayre QA-9 ADC at 192kHz -> USB connection -> Host PC.

 

John Atkinson

Editor, Stereophile

[mansr]

3 minutes ago, John_Atkinson said:

By "digital" I mean that the decoded MQA analog signals were redigitized for analysis.

It would help the discussion if you used words in accordance with their established meanings. That is, of course, assuming you actually want a discussion.

[firedog]

14 hours ago, KeenObserver said:

Once again I am listening to the non MQA version of Simon and Garfunkel's  Sound of Silence.

 

For your edification:

 

A Stereophile Recommended Accessory for the Last 18 Years: Recommended by John Atkinson, Sam Tellig and Robert Harley

The AudioPrism CD Stoplight (the green pen) is the original CD tweak. Just paint the edges of your CDs to greatly reduce disc read errors and reduce jitter while improving clarity and reducing glare. We have sold the CD Stoplight to thousands of customers in the last decade. This tweak really works and it's affordable and simple to use.

"This stuff works! The cost per disc of this tweak is almost zero...it offers a big bang for the buck and can be confidently recommended!" – John Atkinson, Stereophile

 

Doesn't surprise me that John Atkinson is one of the foremost proponents of MQA.

I seem to remember that it was later determined that the green pen method worked by ADDING a significant amount of jitter to the output - it's just some types of jitter are heard by users as euphonic. 

[mansr]

3 minutes ago, firedog said:

I seem to remember that it was later determined that the green pen method worked by ADDING a significant amount of jitter to the output - it's just some types of jitter are heard by users as euphonic. 

The only "evidence" of this is a blurry scope photo taken under undisclosed test conditions. He didn't even bother mentioning what signal he was looking at.

[John_Atkinson]

1 hour ago, mansr said:

It would help the discussion if you used words in accordance with their established meanings.

 

In my original posting, I wrote "For the MQA versions, I decoded the files with Roon feeding my PS Audio DAC and and digitized the PS Audio's analog out with an Ayre A/D converter operating at 24 bits and 192kHz sample rate."
 

I don't see what's unclear about that.

 

John Atkinson

Editor, Stereophile

 

[Miska]

1 hour ago, John_Atkinson said:

That is what I did for the MQA-encoded files, matching the peak levels of the digital capture of the MQA playback to those of the original files. The MQA files were all unfolded to 2Fs so by running the A/D converter at 4Fs, its own behavior would be out-of-band.

 

That is analog capture, there's unnecessary analog path on the way...

 

[mansr]

30 minutes ago, John_Atkinson said:

In my original posting, I wrote "For the MQA versions, I decoded the files with Roon feeding my PS Audio DAC and and digitized the PS Audio's analog out with an Ayre A/D converter operating at 24 bits and 192kHz sample rate."
 

I don't see what's unclear about that.

It became unclear when you later referred to this as a "digital capture."