MQA Users & Discussion Thread

[dopplershifted]

I've had second thoughts about this.

For old analogue masters, why not re-encode or remove the pre-ringing of the ADC from the creation of the digital master.

Peter Craven's earlier work on Apodizing filters was intended to be used in that way. Trouble was, it should only be done once, and his proposal to use an uncommitted AES bit for a flag was not accepted.

Also, I don't think the impulse response of the older Craven filters was likely as short as the new MQA filters because the former were constrained by Nyquist sampling theory and new ones aren't.

So what happens if you then remove the pre-ringing? You do have something different to the studio master. If the recording engineer did their job really well, they may have at least unwittingly compensated for it. Remove it, and you may get something that actually sounds "processed" or as if the engineer now made wrong choices.

MQA encoding is essentially like remastering an album: Someone responsible should sign off on the result. My understanding is that the Authentication LED won't light up unless that has happened. The alternative (and maybe more common?) procedure is that the streaming company does it on their own volition, just as they encode MP3's today. But then the LED won't light. Famous albums would probably get the upscale remastering + Authentication treatment because then the label can convince you to buy a loved album one more time.

So? the purist approach, that we can now have copies of the original studio master, still stands. And we can deal with pre-ringing in ADCs in any number of ways for new and future recordings.

Only if the "original master" is genuinely digital. But even some Pro Tools mixes were processed partly in analog and the final result captured on analog tape. The next step was a digital transfer for replication use, but you can't call that the genuine master.

David L. Rick

Seventh String Recording

Sent from my Venue 8 7840 using Tapatalk

[Guest Bonobo]

Redbook cannot replicate a perfect square. Not mathematically possible.

 

bandlimit squarewave in 0 - 20khz (as you must) ....   and there is no error using CD sample rate.

Edited February 8, 2016 by Bonobo

[Guest rmpfyf]

Of course there's error if you're trying to replicate a square wave.

 

But this isn't music.

[Guest Bonobo]

of course there is NO error if the squarewave is bandlimit from 0 to 20khz, as it must be for digital audio when sampling with CD speed.

 

 

I know what you mean. you are right that it 'isn't music', but the response to square wave tell about all other response, so it is good to quantify the performance.

[Guest Eggcup The Daft]

@@dopplershifted

 

Thanks for the clarifications.

 

I actually understood that the MQA encoded file was signed by the codec for the authentication light to come on (i.e. if the MQA encoded file was tampered with afterwards, the light would stay off). This means that if, say, Tidal encoded a CD, the light will come on. If the MQA file is prepared by the studio, using the appropriate encoder, the light will be in a different colour indicating an "MQA Studio" file.

 

I still can't see, though, how the studio is prevented from processing the master (for example by dynamic range compression), then encoding the result and still generating a file that lights up  - as a "studio" file. As you say, creating the MQA file is "llke" remastering -  I would go further, and say that at least the big companies, at least, will treat it exactly as a remastering process.

 

The ProTools mastering to analogue is not something I had heard about. Of course I should have specified digital masters, though, regardless.

[Guest rmpfyf]

of course there is NO error if the squarewave is bandlimit from 0 to 20khz, as it must be for digital audio when sampling with CD speed.

 

 

I know what you mean. you are right that it 'isn't music', but the response to square wave tell about all other response, so it is good to quantify the performance.

 

I know where you're coming from though this is a fairly outmoded perspective. 

 

PCM encoding is based on a Fourier approach to psychoacoustics, and having the ideal as something that has inherent and infinite ultrasonic content is not a relevant ideal.

 

There are applications where it can matter - evaluating transformer performance etc - but in terms of encoding/decoding of playback material, it's not a relevant metric. 

[malsound]

 

http://www.computeraudiophile.com/content/681-my-first-24-hours-mqa/

 

 

[Guest AndrewC]

http://www.computeraudiophile.com/content/681-my-first-24-hours-mqa/

 

Thanks for that!

 

“Edit 1: I just received a quote from Alan Silverman, Mastering Engineer on the Judy Collins track When I Go:

...

More specifically about the track When I go Alan said, "I’ve just compared the MQA playback with my original 88.2k 24-bit master and find the MQA to be mystifyingly more satisfying, and not by just a subtle shade. Listening to Willie and Judy, their voices sound much more real, at the same time, they have a textural filigree and detail of tone that I am not hearing in the original master! The same holds for the banjo and the subtle electric guitar in the right channel. I am delighted and extremely enthusiastic about the MQA process.”

 

“Better” than the original digital master?! :o… Hmmm….

[Doggie Howser]

Thanks for that!

 

“Better” than the original digital master?! :o… Hmmm….

 

Might be because MQA also includes a reconstructing filter which may be better than the master with a not so good filter?

[Guest AndrewC]

Might be because MQA also includes a reconstructing filter which may be better than the master with a not so good filter?

 

I suspect you’re spot on  :)

 

Assuming this guy is listening via the same Meridian hardware to both tracks, that would suggest Meridian’s MQA Apodizing filters are more advanced than their normal Apodizing filter which they’ve been refining since ’04.

[malsound]

[embed=425,349]

[/embed]

[petetherock]

Been reading a fair bit about this:

http://www.theabsolutesound.com/articles/beyond-high-resolution/

 

 

http://www.whathifi.com/advice/mqa-audio-what-it-how-can-you-get-it

---

MQA in Practice

Before getting into the technical aspects of MQA, let’s review the basics. Master Quality Authenticated is an innovative and sophisticated new method of encoding digital audio that simultaneously improves fidelity and lowers the bit rate. It’s a suite of technologies that addresses the limitations of conventional digital audio by rethinking the entire chain, from acoustic source to playback device. It was developed by Meridian Audio co-founder Bob Stuart and longtime collaborator Peter Craven of Algol Applications.

 

 

In practice, MQA is delivered to listeners as a conventional lossless file, such as FLAC or Apple Lossless at 44kHz or 48kHz at 24 bits. If you play the file though a DAC without an MQA decoder, you’ll hear better-than-CD sound quality. If you play the file through a DAC with MQA decoding, you’ll hear the sound in the studio’s original bit rate, which could be anything from 44.1kHz to 384kHz (or higher), provided that your DAC can handle the studio’s sample frequency. This single-file hierarchical aspect of MQA has important implications for the technology’s adoption by record companies and content distributors.

 

 

The decoder can be implemented in many ways—partly integrated into a DAC chip, or as a bit of software in a phone, for examples. Every decoder will indicate to the listener when an MQA file is playing. Here’s where the “Authenticated” part of Master Quality Authenticated comes in; the MQA light or icon assures that what the listener is hearing on playback is exactly what the engineers heard in the studio. How does this happen? MQA ties the studio’s analog-to-digital converter and the listener’s digital-to-analog converter into what is effectively a single system. In addition, MQA’s rich metadata carries information about the particular analog-to-digital converter and encapsulation used to make the recording or transfer so that the decoder can play it back correctly. And if the decoder knows what DAC it’s driving, it can also optimize its sound. This is why MQA can claim to authenticate the studio experience for the listener.

 

 

As of this writing, more than fifty companies—from major players to niche high-end firms—plan to support MQA with compatible playback devices. Meridian has already launched its first MQA-capable DAC, the $299 Explorer2. The lossless streaming service Tidal is behind MQA in a big way; it will begin streaming MQA files in Q2 of this year. MQA allows Tidal to give its customers real high-resolution streams in a format that fits Tidal’s existing distribution infrastructure. In an e-mail exchange, Pål Bråtelund, Strategic Partnership Manager at Tidal, said: “At first, I thought the last thing the industry needed was another codec. But then Bob [stuart] played some recordings I knew extremely well, and I instantly understood that MQA may be what makes people talk about great recordings and great music rather than about ‘hi-res.’”

 

For Tidal, and also for the world’s record companies, MQA solves the big problem of multiple inventories for different playback applications. A single MQA file works for every listener on every device. This backward compatibility and single inventory are powerful incentives for record companies and content distributors to adopt MQA—quite apart from the improved sound.

 

 

---

Anyone into this?

[Guest AndrewC]

There's already another thread on this;

 

http://www.xtremeplace.com/yabbse/index.php?topic=190717.msg1037865#msg1037865

[Guest CASH]

wow! so my pioneer DAP can do that???

it say's MQA!! Yippee!!!

but 1st things 1st....

I need to find a way to import my CD's n SACD's into it... hahahaha!!!

[petetherock]

wow! so my pioneer DAP can do that???

it say's MQA!! Yippee!!!

but 1st things 1st....

I need to find a way to import my CD's n SACD's into it... hahahaha!!!

Here bro, an MQA update for your player:

http://www.soundandvision.com/content/mqa-update-now-available-pioneer-and-onkyo-portable-music-players#ylfyU0A6k8O1UkqC.97

[Guest CASH]

Thks bro.

But sadly now I am oveseas n didnt bring it along with me, as I have nothing stored on it!

;D

Once I am back, I will update it n wait for some dsd's to load into it.

Quite a few bros are sharing files with me.

Only thing is that a few of the bros r overseas too!

;D

[malsound]

 

http://www.computeraudiophile.com/content/694-comprehensive-q-mqa-s-bob-stuart/

 

 

[Guest AndrewC]

http://www.computeraudiophile.com/content/694-comprehensive-q-mqa-s-bob-stuart/

 

Thanks for that!

 

Not sure how many of you read this whole piece…. Holy smokes! :o (and not in a good way).

 

As far as I can tell, there are no parallels anywhere for MQA’s level of complexity in information delivery. That alone tells me MQA, at least in its full form, is doomed to failure.

 

I also don't like the completely proprietary nature of the MQA chain. IMHO, only a fool would voluntarily want to be locked into such a system. No wonder MQA is trying to claim the end result is "better than the original”; no one would even give them the time of day if it only “matches” lossless high-res at lower transmission bit rates.

 

Bob & team are very smart cookies, but this just really smells bad. ::)

[Guest AndrewC]

Read the latest May/June’16 issue of The Absolute Sound; Robert Harley is so over-the-top and gushing on MQA, it’s well past absurd..  And not a single word mentioned on the totally proprietary single-vendor locked-in nature of the technology ::).  He’s destroying his reputation and credibility on this IMHO.

 

[crazysurfer]

Read the latest May/June’16 issue of The Absolute Sound; Robert Harley is so over-the-top and gushing on MQA, it’s well past absurd..  And not a single word mentioned on the totally proprietary single-vendor locked-in nature of the technology ::).  He’s destroying his reputation and credibility on this IMHO.

 

Tat means the returns must b bery attractive for him to resort to such absurdity.

[essem]

Sorry if its been referenced elsewhere, but Bob Stuart's answers to the Q&A on CA are now available:

 

   http://www.computeraudiophile.com/content/694-comprehensive-q-mqa-s-bob-stuart/

 

There's alot to take in there. I asked Q42 about decoding requirements. Its software only, not hardware, which is good. But I'm not sure I fully understand his answer -- does he mean the MQA decoding needs to happen In the DAC itself (see A42a) rather than it happening upstream, for example in a playback device which just generates USB or spdif input for the DAC? Oh well, at least his answer to Q42c is not a flat no. 

 

I should add -- kudos to Bob Stuart who seems to have genuinely spent a huge amount of time trying to give fullsome answers to all questions. Thankyou Bob, and to CA for the opportunity to ask.

Edited May 1, 2016 by essem

[Guest Sime]

I want to know to, I didn't quite get an understood answer from your question either.

When my Node2 becomes MQA capable, all I need still is my 2Qute dac and I've got full MQA capability?

Edited May 1, 2016 by Sime

[Guest Muon]

Damn it!

 

I thought this was a thread about Massive Quantum Accelerators

[essem]

Indeed, Sime, enquiring minds want to know! Looks like the decoding is in the DAC so far but its very early days e.g. Mytek have announced an firmware upgrade for their Brooklyn dac that provides MQA support:

 

   http://www.theabsolutesound.com/articles/mytek-release-mqa-firmware-update-for-new-brooklyn-usb-dac/

 

and Brinkmann's Nyquist DAC claims MQA decoding:

 

   http://www.brinkmann-audio.com/main.php?prod=nyquist&cat=default?=en

 

Other than Meridian's own MQA DAC, any others yet? 

 

Aha! I see Mr Darko is on the hunt: 

    http://www.digitalaudioreview.net/2016/04/the-mqa-revolution-brother-you-have-to-wait-and-see/

Edited May 1, 2016 by essem

[Martykt]

Damn it!

 

I thought this was a thread about Massive Quantum Accelerators

You should start one.......

I wonder what the digital format will look like once Quantum computers get off the ground.......