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artto

MQA (round two)

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It's been nearly a year since my original post. I've read and watched and lot of criticism on this subject. Admittedly, none of it to my satisfaction, especially after having read the AES papers on the subject. OTOH, virtually everything I've seen posted criticizing MQA has shown at least some, if not much lack of understanding.

 

Right now, I'm with the MQA crowd. Here's why.

 

At Axpona 2017 I kind of got caught in one of the larger high-end rooms after hours. The equipment in this room was Wilson Audio Wamm Master Chronosonic speakers, D'Angostino Momentum amplification, StromTank power supplies, and dCS Vivaldi source.

 

A person in the room had brought along some recordings. At this point I don't know who this person was, or what the recordings are. He simply wanted to see what everyone thought. I happened to grab the sweet spot seat before all this starting happening (after hours). He played two versions of three recordings (classical music). At this point the question after each comparison was simply which do you prefer and why?

 

As it turned out, everyone agreed on which one they preferred. And similar descriptions of why. At this point I said to the guy with the recordings, you seem like someone I should know! It turns out this was Pete McGrath, a well-known recording engineer. In fact I had just purchased one of his recordings a few weeks before & have many more in my collection. Since I've been recording live chorale/orchestral music and producing recordings for a local organization for 30+ years I found this fascinating.

 

After listening, McGrath revealed the details of how the recordings were made, mics, sample/bit rates, etc. It was only afterwards that I found out that which one of the recordings was MQA. What? What the hell is MQA I thought. Yeah, I've been living a cave for an audio hiatus for a while since I upgraded and changed EVERYTHING a few years ago. So I no clue what MQA was. But I must tell you, in all three instances MQA sounded better than the "raw" 96kHz/24bit original.

 

But wait, isn't the "copy" not supposed to sound better than the "original"? It's supposed to sound the same, right?

 

A year later I think I've figured out why (and how). Yeah, I'm slow, but eventually I get it. From what I understand so far, what we've been getting in the form of recording is not quite a "copy" of the original. IMHO this is a game changer.

 

So fire away.

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@artto Have you seen this from the man Bob Carver:

 

From the BobFather

The Emperor’s New Encoding:

My Futile Quest to Authenticate MQA

Human perception is easily fooled into imagining differences that don’t stand up to empirical proof. MQA (Master Quality Authenticated), a new Tidal Music streaming audio format, takes its place alongside
mystic resonating aura crystals, magnetic bracelets and countless other miracle schemes: It is much ado about nothing…for fifty cents extra per download! It’s not what reviewers heard several years ago. It is provably smoke and mirrors.

I assert that MQA is perhaps the biggest hoax, the biggest prevarication, the biggest deceit ever foisted off on the music listening public. To prove it, I set out to use science instead of subjective listening to determine the extent of differences between MQA and a standard CD of the same song. The results were beyond disappointing to anyone hoping for, as Robert Harley extolled in a recent The Absolute Sound editorial, a “paradigm shift”.

First a Bit of Background. Late in 2014, following an Audio Engineering Society convention, Bob Stuart, co-founder of Meridian Audio, demonstrated a new lossless format called MQA to key audio journalists, using specific musical tracks and equipment in controlled listening sessions. Writers were told that MQA was a new digital system that eliminated “time smear,” increased clarity, encoded signals better than the Nyquist-Shannon Theorem (which is indisputably the fundamental underpinning of all of digital audio) and could stream songs using a slow roll-off filter that let through important ultrasonic frequencies, allowing
music to sound better. There was some consensus among journalists that it sounded better than conventional CD tracks

(see the Original Flavor MQA Was Tastier sidebar at right).

At the 2017 Consumer Electronics Show, Tidal officially unveiled Tidal Master with MQA, a new “tier” above Tidal Hi-Fi, which they claimed would “fundamentally change the way we all enjoy music”. I personally
applaud Tidal’s efforts to wean listeners off MP3… as well as offer a more generous artists’ royalty policy (Tidal is partially owned by rapper Jay Z). But getting involved with MQA I’m not so sure about.

Learning About MQA.

As an amplifier and speaker designer, I am often asked to address audio clubs. A dealer asked if I would be including an MQA decoder in a future preamp. I had heard of MQA, primarily due to Robert Harley’s The Absolute Sound editorials, but paid little, if any, serious attention. But now I wanted to learn more. My first thought was to contact Robert E. Greene, a reviewer who had written about my new loudspeaker, and a seasoned veteran of things audio. Surprisingly, Robert had no specific technical knowledge of the MQA process that he could pass on: I was left to my own devices. So, I read reviewers’ and tech writers’ blogs,
watched several videos on MQA and even waded through the 2014 AES Convention Paper 9178 that had launched the “new” technology. It claimed “improved time/frequency balance” using “loss-less buried-data signaling within the channel to carry instructions, metadata and authentication” and “innovation-rate concepts” for reducing temporal blur. What gobbledygook, I thought. The patents that had been filed were of little additional help (see the Patent Medicine sidebar on the next page). It was time for some
serious testing. The Null Test. She Don’t Lie. Now, it’s difficult to view an audio waveform on even the finest electronic test equipment and know much about the music it represents. Beethoven looks the same on an oscilloscope as Mozart. Making mean assertions about MQA using standard tests would immediately get batted down by cynics. Luckily, there is an incontrovertible way to compare two version of the same audio. Done properly, the Null Test is the perfect mathematical proof that two audio signals are identical. Also called a Difference Test, Null Testing demonstrates that two audio streams are identical when the difference signal is exactly zero. On the surface, this is quite simple: Just mix two signals together while flipping the polarity of one of them. If the result is pure silence, the two signals are equal, bit by bit.
Actually, in the digital domain, this is more complicated that it might first seem. If two waveforms
are off by just one sample — even at mind-boggling sample rates like 768 kHz — the null test won’t be
valid. I turned to a very expert colleague, Ronald Brandt, to do the actual Null Test. Tidal Master Track (MQA) and non-MQA Tidal Hi-Fi tracks were downloaded from the web; the identical songs were accessed from “traditional” 16-bit/44 kHz compact discs, and 24-bit/192 kHz versions. Ron is meticulous and left nothing to chance. He spent far more hours in a Digital Audio Workstation program, recording, editing, eliminating timing drift and signal inverting than he did doing the actual comparison. After all this effort, he created a digital transfer recording of the resulting null that totally bypassed analog stages. Before we go any farther, let’s make sure you understand what we mean by “null”. Null difference testing consists of combining two different signal sources with identical levels, but out of phase by exactly 180 degrees. If the two signal sources are 100% identical, no sound will be heard — they’ve perfectly cancelled each other out. If sound is heard, the two signal have different properties and the differences are what’s audible. Null testing is absolutely indisputable. It’s pure mathmatics at work: 1 plus minus 1 equals zero. Ron begain with CD and Tidal MQA versions ofsome different genres of musical material. Both versions of the signals were then fed to both a Meridian Explorer 2 and Mytec Brooklyn DACs, MQA versus CD. MQA-on versus MQA-off. Care was taken to make sure the null was evaluated at the loudest part of recording where the brick wall limiter applied to the master was being ridden quite hard. Then the actual null test was performed on the same test equipment. Any differences between the CD and MQA versions would result in a waveform consisting only of those differences. The null test results are not visually exciting, but VERY conclusive.

The two versions of Emmylou Harris yielded……a tiny but inaudible difference (the fuzzy parts of the blue lines).

BOTTOM LINE: MQA was the same audio signal that was contained in the original signal source. By “the same”, I mean that it yields an approximate –70 dB null when compared to the original source. Personally,
I am unable to hear a difference between them once the null is –50 dB. At –70 dB, even a passing bat would not be able to hear any differences. Why My Attorney Had to Review This Before I Published It.
There is no enhancement and nothing special with Tidal Master MQA. If you listen to the streaming of a stock song and compare it to an MQA streaming of the same song, they sound the same.
The experiences reported by reviewers was an early version of MQA “doctored” with cross-talk cancellation. The signal available to the public contains none of that. It’s just an ordinary copy of the original. It does not work by getting rid of “pre-ringing”. It does not work by “turning Shannon/Nyquist on its head,” though several knowledgeable people that should know better. It is a pass-through with simple noise shaping (nothing new in itself) that reduces the apparent signal-to-noise ratio in a way that is good. MQA is a paradigm shift only in the sense that it allows Tidal to violate the listener’s privacy. I regret that the reviewers and audio journalists have been unwittingly caught in a big hoax — what they heard did indeed sound different. My fear is that customers now will think they are getting something
very special like the sound the reviewers experienced and wrote about., but what they are really getting is nothing significantly different from the original. By that measure, MQA is a hoax and a big lie!

Bob Carver • Fall 2017

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How about if you let your ears decide...

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jjptkd - first my response to Bob Carver:

 

If you really want to get a handle on how ****ing stupid Bob Carver is, and what kind of pitchman BOB is, all you need to do is read Paul Klipsch's dissertation of the "The Ulimate LSH" (Loudspeaker) published in the Journal of the Audio Engineering Society, March 1974, Volume 22, Number 2, which was also reproduced in the Klipsch Dope From Hope Newsletter Volume 14, No. , April 1974.

 

It's not often that a professional journal such as JAES allows one of it's members to publish such a scathing (but humorous) response to another member "Carver's Law".

 

You can find it here on the Forum somewhere, a PDF called "The Paper", originally provided by yours truly (all the hand writing seen in this copy is my own).

 

I'm not a fan of Bob Carver or his products although I've always loved the way they look. His above dissertation on MQA that you have so kindly provided is incomplete (on Bob's part) and shows he did not do his homework, and what homework he did do is wrong. He is, above all things, a purveyor of hoax himself, so I guess he knows, right? (It takes one to know one?)

 

Next 😎

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12 hours ago, Schu said:

How about if you let your ears decide...

 

Yep.

 

That's what I did.

 

And I might add, that comparison "test" was about as blind as one can get. I didn't even know what MQA was until after the fact. I just knew that one of each of the three recordings sounded more like the real thing, especially the solo piano piece.

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2 hours ago, artto said:

jjptkd - first my response to Bob Carver:

 

If you really want to get a handle on how ****ing stupid Bob Carver is

 

I have personally met and talked with Bob Carver on a few occasions and he is nothing short of genius to try and discount his statements on the basis that he is "stupid" and you know what you "hear / heard" is ludicrous to me, sorry.

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1 hour ago, jjptkd said:

 

I have personally met and talked with Bob Carver on a few occasions and he is nothing short of genius to try and discount his statements on the basis that he is "stupid" and you know what you "hear / heard" is ludicrous to me, sorry.

 

Well, I've met and talked with Bobby too, and more than a few occasions. I don't consider him any kind of genius. Perhaps that's because I'm more intelligent than you? Paul Klipsch certainly did not consider him a genius. And that's what my response to your response is about. Please read it (The Paper) if you haven't done so.

 

Furthermore, if YOU don't have any direct experience with MQA, please don't waste my, or other's time by posting responses or links from other individuals criticizing MQA without having done the homework. I'm not interested in a pissing contest.

 

Yes, I think Bob Carver is stupid. He's proved it, on his own, once again. How? Let me pick on his first sentence of what you posted from "the Bobfather".

 

1. “Human perception is easily fooled into imagining differences that don’t stand up to empirical proof. MQA (Master Quality Authenticated), a new Tidal Music streaming audio format”

 

In Carver’s first sentence, he has already put forth not one, but TWO misleading and untrue statements.

 

One, that Tidal is somehow “in” on the research and development of MQA or is somehow "part of it" and implies that it something exclusive to Tidal and its streaming services (which it is not)

 

And two, that it is a streaming audio “format” (which it is not). It is a CODEC which can be encapsulated with ANY FORMAT, audio or video.

 

If a supposedly educated and certainly well known purveyor of high quality audio can’t even get his facts correct in the first sentence, what am I to make of anything else he has to say on the subject?

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I don't have a dog in this fight, but I certainly didn't perceive that implication.  Simply, MQA is a format that Tidal is newly streaming.  Not that Tidal was either behind it or that it was exclusive to them.  But then I had no expectation or preconceived idea there was anything more to the introductory statement.

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Is this MQA stuff something that really keeps you up at night?

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Qobuz is in Europe and they offer "encoded in 24-Bit, at frequencies that can go up to 192 kHz - these are actually the same files that are used in recording studios." For streaming and download.

They don't mention MQA. Why (not)?

 

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19 hours ago, Schu said:

How about if you let your ears decide...

Agree!!  I have yet to hear a difference and I can switch between MQA and non-MQA versions very easily with Tidal + Roon.  I'm not saying there isn't a difference, but I just can't hear it.  A solution in search of a problem IMHO.

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2 hours ago, glens said:

I don't have a dog in this fight, but I certainly didn't perceive that implication.  Simply, MQA is a format that Tidal is newly streaming.  Not that Tidal was either behind it or that it was exclusive to them.  But then I had no expectation or preconceived idea there was anything more to the introductory statement.

 

Again, for the x100000000 time. MQA is NOT a FORMAT

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2 minutes ago, pbphoto said:

Agree!!  I have yet to hear a difference and I can switch between MQA and non-MQA versions very easily with Tidal + Roon.  I'm not saying there isn't a difference, but I just can't hear it.  A solution in search of a problem IMHO.

 

Again......you can't hear it. Therefore it's a solution in search of a problem.

 

If you have auditioned MQA and non-MQA versions please state the conditions. Like what were you using? What you are using on the receiving end can and should make a difference as how much or little of an effect MQA has. For example, if you're using the Tidal app on your PC with a Chrome browser you are not going to get the full benefit of MQA regardless of the original recording source.

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MQA-encoded files are offered by Tidal as one of several digital "formats" available for delivery.   I could listen to lossy, lossless, or whatever if I were a Tidal subscriber.  I understand what MQA is and what it purports to be.  I don't think it's worth the extra cost, but I still don't have a dog in this fight.

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2 hours ago, avguytx said:

Is this MQA stuff something that really keeps you up at night?

 Yes, it is.

As I have previously stated (but not many people reading apparently) I am not only interested in the playback, but also the recording side of the equation.

What I heard from Peter McGrath's recordings with and without MQA - before I ever heard about MQA and had no idea what it is or what it's supposed to do ---> a totally blind listening condition, I was surprised. And I, like Pete McGrath's point of reference is live acoustic music. I don't have the extended experience that McGrath does but I do have a lot more experience at this than almost Forum members.

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1 minute ago, glens said:

MQA-encoded files are offered by Tidal as one of several digital "formats" available for delivery.   I could listen to lossy, lossless, or whatever if I were a Tidal subscriber.  I understand what MQA is and what it purports to be.  I don't think it's worth the extra cost, but I still don't have a dog in this fight.

 Please refrain from referring to MQA as a "format".

 

Is it really that difficult for everyone to understand the difference between a CODEC and a "format"?

 

What you, and others don't seem to understand is that MQA can be had as both lossy, and lossless, depending on how it's received (ie: available bandwidth) and what is used for decoding (or no decoding) on the receiving end.

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What I understand is that MQA encoding allows extra bit-depth to be delivered in whatever format (i.e. "container").  If the format is natively at that bit-depth then there's no need for it.  What am I missing?

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You formed your opinion based on one engineer's three recordings at Axpona 2017?

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2 minutes ago, pbphoto said:

You formed your opinion based on one engineer's three recordings at Axpona 2017?

Do you have something better to go on?

 

How many recordings of live acoustic music have you made? How many CD have you produced and sold?

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9 minutes ago, artto said:

 

Again, for the x100000000 time. MQA is NOT a FORMAT

Maybe you want to spend some energy telling these folks below it isn't a format.  I'm not sure why you're hung up on this.  I agree with you that people should just give it a fair shake and listen, me included, but it is confusing when multiple sources are calling it a format while you are saying it is not.

 

What's the easiest and least expensive way for me to hear it for myself?

 

https://www.cedia.net/insights/cedia-blog-detail/blog/2016/01/15/closeup-lifetime-achievement-award-recipient-robert-stuart

https://www.cepro.com/article/meridian_on_new_mqa_lossless_audio_format_artist_authenticated/

http://www.realhd-audio.com/?p=3851

http://www.hifiplus.com/articles/mqa-its-about-time/

https://www.stereophile.com/content/ive-heard-future-streaming-meridians-mqa

http://www.tonepublications.com/industry-news/the-latest-high-resolution-format-from-meridian-audio/

https://mytekdigital.com/hifi/mqa/

https://www.audiostream.com/content/mqa-love-or-hate-creator-bob-stuart-speaks-audiostream-podcast-no1

 

 

 

 

Screen Shot 2019-02-08 at 5.05.50 PM.png

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