Meridian MQA

[Pseudo]

Meridian lance actuellement un nouveau format de fichier audio nommé MQA, "master quality authenticated"  

Bof! pourrait être la première réaction. Néanmoins le système semble prometteur par deux caractéristiques:

1. il est compatible avec tous les formats existants
2. il procède à une sorte d'échantillonnage variable en fournissant des "bits" là où ils sont nécessaires, en se basant sur le fait que le niveau le plus élevé d'informations qu'on peut attendre décroît avec la fréquence (la définition de cette enveloppe probable est nommée "encapsulating").

Je laisse la compréhension technique du procédé à ceux qui ont le goût (et les capacités) de ces aspects. Des informations peuvent être lues ici.

Ce qui paraît intéressant, c'est que la stabilité temporelle des échantillons est annoncée comme très supérieure à celle du CD. Les oscillations avant et après le signal  provoquées provoquées par le filtre à pente raide "brickwall" conformes à la théorie de Nyquist disparaissent entièrement, ce qui est encore mieux que les DAC qui offrent l'"apodising". Dans cette technique, la pré-oscillation est simplement retardée et apparaît après le signal, ce qui est certes plus naturel, mais constitue toujours une forme de distorsion.

Des commentaires? quelqu'un a-t-il eu l'occasion d'assister à une démonstration?

[zeroundemi]

..........

[Pseudo]

Il est vrai qu'Atkinson insiste sur l'aspect de la compression. Son article date de quelques mois et il est possible que Meridian ait voulu cacher certaines caractéristiques de son "bébé" avant le lancement officiel.

Dans le dernier Absolute Sound, toutefois, Harley insiste sur d'autres aspects et donne la "parole" à Stuart qui s'étend sur l'exactitude temporelle que les concepteurs ont voulue pour tirer les conséquences de découverte en neurosciences. Les CD et fichiers codés MQA sont réputés mieux sonner que des FLAC 44/16 ou des CD. Ceux qui ont eu l'occasion d'écouter ces fichiers décodés ont publié des CR très favorables.

Mais TAS n'a pas mis son article en ligne, et je ne pouvais donc fournir de lien.

Wait and listen!

[zeroundemi]

..........

[Pseudo]

... le CD canal historique étant relégué au rayon des antiquités objet de tout l'intérêt des amateurs de vintage  

Je suis donc un "amateur de vintage", à l'insu de mon plein gré    car j'avoue que l'ébullition permanente du monde informatique n'est pas ce que je désire trouver lorsque je gagne ma salle de musique pour écouter un bon enregistrement...

[shal]

Mouai, pas convaincu.

De ce que j'ai compris :
- Il font des hypothèse que l'information au delà de 48khz n'est pas très loin du bruit
- du cou, il arrive a planquer cette information vers -130db dans la bande des 24-48khz
- et ils font pareil avec l'information entre 24 et 48khz qu'ils planquent vers -148db dans la bande des 0-24khz

Au final ils ont un fichier 24/48khz où toutes l'information pertinentes d'un 24/192khz serait présents.
Et en effet avec du matos classique on peut lire ce 24/48khz et avec du matos qui connaîtrais ce format ils pourrait "reconstruire" le 24/192khz.


Pour résumé : une bidouille , astucieuse mais une bidouille.
Avec un peu de marketing ça peut passer pour une révolution  

[zeroundemi]

..........

[Cartel]

TAS mai-juin 2015.

[Pseudo]

Dss nouvelles du MQA dans Stereophile.

Ce que je n'arrive pas à comprendre, c'est l'affirmation que MQA diminue le "time smearing" (la distorsion temporelle?) du signal: comment cela peut-il être réalisé dans le software?

Mytek to Support MQA
By Jason Victor Serinus • Posted: Oct 12, 2015

Exciting news greeted the posse of press who headed to the Marriott Denver Tech Center's Atrium Saturday October 3 for a press conference entitled "MQA and Mytek Present: From Studio to Home." Both Bob Stuart of MQA, Ltd. (above right) and Michal Jurewicz of Mytek Digital (above center) were present, as well as Pål Bråtelund, Strategic Partnership Manager for Tidal (above left), and, for MQA partner AudioQuest, AQ VP Steve Silberman.

Thanks to a lovely-sounding assemblage of components—Vandersteen's Model Seven loudspeakers, Boulder 1060 stereo amplifier, and AudioQuest cabling—we were able to take a first listen to Mytek's Brooklyn ($1995), an idiosyncratically styled, compact USB2 DAC/preamplifier/headphone all-in-one that will ship in early December. Touted as "the world's first stand-alone, high-performance DAC with MQA®technology," the 4 lb, MQA-equipped Brooklyn converts up to 32/384k PCM (including DXD), and native DSD up to DSD256 (DSDx4). It also claims a 130dB dynamic range, which should be sufficient for sending your chickens and more running for cover.

At the conference's start, Stuart (above) laid down the bottom line: "You can take an MQA-encoded file, play it anywhere, and it will sound better than CD."

"Our hearing is much more sensitive to timing information than we thought," he continued. "Because of our ingrained sense of survival, human beings are at least five times more sensitive to timing information than to frequency. We can discern time intervals of a few microseconds.

"What works perfectly for instruments doesn't work for digital filters, which smear timing. CD smears timing for 4 milliseconds, which is the equivalent of sound traveling 4 feet. With MQA, we've redesigned the way digital sampling is done. MQA reduces ringing and smearing dramatically, over ten times more than on 24/192 recordings."

What Stuart did not address at the conference, however, was the unexpected delay in MQA implementation. After the announcement at May's Munich High End Show that MQA, Inc. had over 100 strategic partners, everything has been quiet. Rumor had it that MQA decoding was requiring more battery power than was practical for mobile phones to supply.

Asked to comment on the situation, Stuart replied by email:

MQA saw it necessary for a small delay to optimize the delivery platform in order to provide more flexible streaming. MQA has also been preparing decoders for the mobile platform, but the most important aspect to note is that the audio is still amazing and unchanged. MQA has been busy building the supply chain. By working to increase the efficiency of the delivery, with no compromise to the audio, we make MQA a better company to do business with.

We have many customers in the pipeline in addition to the following manufacturers that have recently announced including AudioQuest, Pioneer, Onkyo, Bluesound and Mytek. And you should expect more by [the 2016] CES.

After Jurewicz (above) gave us the lowdown on the Brooklyn, the two men played snippets of several MQA-encoded selections. The first was a beautifully recorded Frank Sinatra track from 1957 whose lyrics were so soppy that they seemed destined for an entire collection of Hallmark cards. (I am not exaggerating!) Then came an equally sentimental, easy listening, DXD piano recording from Morten Lindberg's 2L label.

The icing on the first layer of the cake was part of a brand new duet by Judy Collins and Willie Nelson, entitled "When I Go." Along with it came a glowing endorsement from Alan Silverman, who has been recording Collins for 40 years. Silverman unequivocally states that encoding and decoding his master file with MQA produced a recording that was clearer than the original master.

While Silverman's endorsement is of major importance, it was difficult to listen to the part of the track that was played without conjecturing that the aging voices of both Collins and Nelson had been heavily processed. How anyone was supposed to know that this track sounded "better" than the master was beyond me.

This frustration was compounded by the fact that no one offered before/after comparisons of any tracks. I heard those comparisons at Audio High in Mountain View, CA, before John Atkinson and I filed our first reports about MQA, and was immediately convinced of MQA's efficacy. What I don't understand is why such comparisons were not conducted either here or at previous public demonstrations of MQA that have taken place at a number of venues, including both the 2015 CES and Audio High.

Be that as it may, the next exciting piece of news was that Mytek will take the Brooklyn's as yet unnamed sister A/D converter to the AES convention in New York City, October 29–November 1. The unit, which includes an MQA kernel, will be given to unnamed recording engineers to play with. What will happen after that could very well change recording history. I am certain that John Atkinson and other Stereophile East Coasters will be on hand to report everything that takes place.

At conference's end, Bråtelund served dessert. He took a huge risk by daring to stream, over the Marriott's terrible, soon-to-be redone WiFi network, an MQA-encoded hi-rez file (24/352.8k) of a recent 2L recording, Kim André Arnesen's soppy Magnificat. Actually, I don't know what was riskier, daring to trust a network that kept crashing time after time in room after room, or inundating press with so much sop that we risked drowning in ooze. Thankfully, the selection was short, and the experiment a sonic success, due to the major reduction in streaming bandwidth made possible by MQA. (The MQA process packed the 24/352.8k data into a 24-bit lossless FLAC file sampled at 44.1kHz.) I left the room excited at the prospect that MQA, Mytek, and Tidal are poised to take music playback to a whole new level.

[Pseudo]

ça bouge...un peu:
http://www.theabsolutesound.com/article ... =email-456

[Pseudo]

Meridian lance une mise à jour pour installer MQA sur ses produits:
http://www.stereophile.com/content/meri ... oducts-mqa
tandis que les éditeurs pratiquent l'attentisme...

[jeanpascalg]

Ils ont fait une démo de ce truc au dernier salon d'octobre te je n'ai rien entendu d'exceptionnel.

[yannig]

http://archimago.blogspot.fr/2016/01/me ... ality.html

je ne saisis pas bien l'intérêt du truc.