MQA discussion

awsmone

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Real world example:

1. The studio creates a track at 24 bit / 352.8 kHz DXD.
2. The studio uses the MQA process on the track, packaging it as 24 bit / 44.1 kHz.
3. The consumer purchases or streams the 24 bit / 44.1 kHz track.
4. The consumer's playback system decodes and renders the track at 24 bit / 352.8 kHz DXD.


Using the real world example above, the Tidal desktop application, Audirvana, and soon Roon would decode the MQA 24/44.1 distribution file and unpack it to 24/88.2. This file is output from a computer via USB or S/PDIF or even a phone via Lightning or USB on-the-go, to the hardware renderer. For this example, we'll output via USB to an AudioQuest DragonFly. The core decoded file enters the DragonFly at 24/88.2, then expands to the full 24/352.8 kHz resolution of the original studio master file.

Just to be clear

MQA does not have 24 bit resolution

It has 24 bits of data, as the high frequency content is folded down into the last 4-7 bits, this is in terms of streaming

I am unclear if you were to buy a 24/384 MQA master whether that's what u are really getting

Hires website has the same issue, though they have stated that where they know the provenance of the recording that u do get a true high resolution file
 

awsmone

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Since DaveyF challenge to me to go and listen to MQA I have been trying to find a top quality DAC to listen

So far I have tracked down the Meridian Ultradac

are there any others out there

My Meitner has no software upgrade to do yet

I have read that u can do a first unfold in software and get 24/96, so maybe that's where I will start

Any other Suggestions
 

MJB

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A few top DACs supporting MQA, Berkeley Ref 2 DAC, MSB DACs, and soon DCS DACs. There are others...good luck!
 

microstrip

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Francisco,

I agree with still-one, when you're comparing versions of the same album subjectively, all it matters is whether it sounds better or not. That's why I compare 16/44 versions to MQA, DSD, etc, as I don't judge them on their technical merits, but whether they sound good or not.

Surely, if you just want to tell us what you prefer. However if someone, as most of us, is trying to learn something systematic and true about MQA then the details are needed.
 

microstrip

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This can only be true if the MQA is completely decoded by software, which is not how I understand MQA works. The MQA patent states that the final filtering takes place in the MQA-certified DAC, and exactly how the filtering is implemented applies only to that specific DAC, and only recovers the "MQA" audio as analog after the D>A performed by that particular DAC. This is the whole point of MQA certification, otherwise there would be no need, one could use any DAC.

As far as the bit rate, it will be the same as any PCM stream of that specific bit depth and sampling rate. So 16x2x44,100 or 24x2x96,000, 24x2x192,000, 24x2x88,2000 or whatever.

Interesting - it makes some sense. But playback is not so simple. See https://www.audiostream.com/content/mqa-decoding-explained

"If you play back a 24-bit/192kHz MQA-encoded file using iTunes through a regular DAC (i.e. a non-MQA DAC), you will get a 24/48 file.

If you play back a 24-bit/192kHz MQA-encoded file through an MQA software decoder like Tidal HiFi, Audirvana, or (soon) Roon, and you are using a regular DAC (i.e. a non-MQA DAC), you will get a 24/96 file. A software decoder does not offer the ability to 'unfold' the original file to resolutions higher than 24/96 (or 24/88.2).
"

Read more at https://www.audiostream.com/content/mqa-decoding-explained#WKj5JRLU4btj0Wvp.99



Just found in a JA article - Stereophile Aug. 2016 :
"MQA encoding did indeed reduce the size of a hi-rez file: While the 24/88.2 WAV master file for my recording of the Portland State Chamber Choir's performance of "Amazing Grace" is 169.5MB, the MQA-encoded FLAC version is just 51.5MB—30% of the original size, smaller even than the 16/44.1 version on the CD release, which was 55.7MB (footnote 2)."
Read more at https://www.stereophile.com/content/listening-mqa#IfRikYV4QuCSkwLe.99
 
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Al M.

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Surely, if you just want to tell us what you prefer. However if someone, as most of us, is trying to learn something systematic and true about MQA then the details are needed.

+1
 

Al M.

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asiufy

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My bad, then. I will refrain from posting about subjective observations, and let you techies do you thing. I let my enthusiasm take over, because this stuff just sounds great...




thanks,
alex
 

Al M.

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My bad, then. I will refrain from posting about subjective observations, and let you techies do you thing. I let my enthusiasm take over, because this stuff just sounds great...
thanks,
alex

How about both? Subjective observations that can be explained as a result of certain technical parameters?
 

asiufy

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Because a technically better format woudn't necessarily translate into better sounding records/music. Plenty of examples out there.
 

DaveyF

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Has anyone heard the new Mytek manhattan DAC with MQA? Would seem to be a slightly less pricey option.

Alex, I do wonder why people have to question if something sounds better to our ears; as to what is behind that from a scientific perspective...and failing to either a) agree with the science, or b) not understand it, or c) both- have to denigrate the experience that we both have.
Even though these very same people have never heard the format in question, like MQA.
I am pleased to see that awsmone is at least willing to go and listen and then get back to us with his opinion. I will be interested if he shares our opinion of MQA after his demo.
 

asiufy

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Good call on the Mytek! I've heard it at the Wilson factory, as Peter McGrath lugs it around to demonstrate the MQA stuff, when a compatible DAC isn't available otherwise.

I've heard more than one (industry) friend tell me it's a good product, and it must be indeed, given that differences between the MQA and non-MQA versions of his recordings were very clear for all in the room to hear.
 

bonzo75

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Since DaveyF challenge to me to go and listen to MQA I have been trying to find a top quality DAC to listen

So far I have tracked down the Meridian Ultradac

are there any others out there

My Meitner has no software upgrade to do yet

I have read that u can do a first unfold in software and get 24/96, so maybe that's where I will start

Any other Suggestions

You need to listen to the complete unfold. The meridian ultra is superb while playing MQA.
 

rbbert

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Interesting - it makes some sense. But playback is not so simple. See https://www.audiostream.com/content/mqa-decoding-explained

"If you play back a 24-bit/192kHz MQA-encoded file using iTunes through a regular DAC (i.e. a non-MQA DAC), you will get a 24/48 file.

If you play back a 24-bit/192kHz MQA-encoded file through an MQA software decoder like Tidal HiFi, Audirvana, or (soon) Roon, and you are using a regular DAC (i.e. a non-MQA DAC), you will get a 24/96 file. A software decoder does not offer the ability to 'unfold' the original file to resolutions higher than 24/96 (or 24/88.2).
"

Read more at https://www.audiostream.com/content/mqa-decoding-explained#WKj5JRLU4btj0Wvp.99



Just found in a JA article - Stereophile Aug. 2016 :
"MQA encoding did indeed reduce the size of a hi-rez file: While the 24/88.2 WAV master file for my recording of the Portland State Chamber Choir's performance of "Amazing Grace" is 169.5MB, the MQA-encoded FLAC version is just 51.5MB—30% of the original size, smaller even than the 16/44.1 version on the CD release, which was 55.7MB (footnote 2)."
Read more at https://www.stereophile.com/content/listening-mqa#IfRikYV4QuCSkwLe.99
I misunderstood your question. You asked for bit rate, and I thought you meant (as with mp3) the actual bit rate. I was merely pointing out how to calculate it from the display Alex mentioned. But in fact a true "MQA" file doesn't have one, as has been noted; much of the 24bit "resolution" is used to store information for eventual decoding, and the display on Alex's MSB actually reflects the digital PCM resolution of the original file before encoding. As I mentioned, the original "master" is never recovered in digital form, only analog after decoding by the MQA-certified DAC. That's not to say that it couldn't be, but at least at present Meridian and MQA doesn't allow that.
 

rbbert

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My biggest objection, and what should be a problem for anyone, is simple. There is no technical reason why the MQA process needs to be lossy, and no technical reason why all the filtering and DSP mumbo-jumbo needs to be proprietary (except for Meridian to make money). All the audio goodness could be put into a lossless container with appropriate software (not hardware or firmware) at the other (user's) end. But then that would end up being hacked or open-source, and Meridian can't have that...
 

spiritofmusic

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Al, are you familiar w Rush in digital, v analog?
Once you get past the well worn criticisms of Geddy Lee's voice and their overblown arrangements, it can be argued they've always sounded somewhat harsh and grainy or papery on digital.
On vinyl the tendency for a somewhat warmer and wetter bass and more gentle cliff edge in the treble suits them far better than the harder mastering they've had so far.
Even upscaled to 512dsd on SGM server and Dac8 still doesn't do them any real favours.
I believe this is a good example where previous mastering of Rush by engineers in digital w no sensitivity have served bands like Rush poorly.
And that's before we even get into the brick walling of Vapor Trails and later albums.
Alex' reports that Rush on MQA is a lot more dimensional and textured than the equivalent 16/44 or Hi Rez is praise indeed.
 

microstrip

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My biggest objection, and what should be a problem for anyone, is simple. There is no technical reason why the MQA process needs to be lossy, and no technical reason why all the filtering and DSP mumbo-jumbo needs to be proprietary (except for Meridian to make money). All the audio goodness could be put into a lossless container with appropriate software (not hardware or firmware) at the other (user's) end. But then that would end up being hacked or open-source, and Meridian can't have that...

IMHO the most interesting aspect of MQA for audiophiles is what they call "correcting for time domain errors", not the compression. However, does this mean we are paying for extremely expensive clocks for our digital systems and then a Meridian calculated "clock distortion" is being superposed over them to improve subjective sound quality?
 

FrantzM

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Al, are you familiar w Rush in digital, v analog?
Once you get past the well worn criticisms of Geddy Lee's voice and their overblown arrangements, it can be argued they've always sounded somewhat harsh and grainy or papery on digital.
On vinyl the tendency for a somewhat warmer and wetter bass and more gentle cliff edge in the treble suits them far better than the harder mastering they've had so far.
Even upscaled to 512dsd on SGM server and Dac8 still doesn't do them any real favours.
I believe this is a good example where previous mastering of Rush by engineers in digital w no sensitivity have served bands like Rush poorly.
And that's before we even get into the brick walling of Vapor Trails and later albums.
Alex' reports that Rush on MQA is a lot more dimensional and textured than the equivalent 16/44 or Hi Rez is praise indeed.

Spirit

This could be a case of mastering. Not of intrinsic format sound. The same apply to all the MQA kudos. Alow me skepticism
 

awsmone

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Spirit

This could be a case of mastering. Not of intrinsic format sound. The same apply to all the MQA kudos. Alow me skepticism

I am wondering whether MQA uses arithmetic encoding

Two points have piqued my interest

The first is the need to enfold the high frequency content in the lowest bits possibly between 4 and 7

But many people claiming very high audible resolution

The second is JA comment that the MQA file of his recording took up less space than his 16/44.1 file, but superior data content

Many including me have assumed that this means it's a lossy format

However, could it be they are using arthimetic encoding which of course uses less bits ?

I note several high end dacs having to add hardware to do the final unfold eg MSB, Berkeley Dac 2
 

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