Listening to MQA

Last June, Jim Austin briefly discussed the operation of MQA in his review of the Meridian Explorer2 USB DAC, but you can find a more detailed explanation on Stereophile's website here and here. MQA involves two fundamental concepts, discussed in a paper presented to the Audio Engineering Society in October 2014 (footnote 1). The first is responsible for a large reduction in the bandwidth required to store and stream high-resolution files, the second for a potential improvement in sound quality:

• With files sampled at 2x, 4x, or 8x the baseband rate of 44.1 or 48kHz, the information in the one, two, or three ultrasonic octaves can be encoded and packed below the music's baseband noise floor in a 24-bit container. This "music origami" results in a much smaller file size than the hi-rez PCM equivalent, yet when the file is unfolded, the resolution and bandwidth of the original file are preserved. If an MQA file is played without MQA decoding, the sound quality will be that of the baseband file—ie, at least as good as a CD.

• MQA is claimed to be able to compensate for the time-domain errors of both the original A/D converter used to make a recording and the D/A converter used to play it back. This results in the complete recording/playback chain having an impulse response equivalent to a few feet of air, and temporal resolution of the same form and order as that of the temporal sensitivity of the ear-brain.

I examined the first of these claims in an article in the June issue. 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).

My analyses comparing the spectrum of the original WAV file with that of the decoded MQA version did indeed prove that MQA's "music origami" worked, the spectra of the original WAV file and the decoded MQA version overlaying one another exactly up to the 44.1kHz Nyquist frequency of the original recording. The ultrasonic 2Fs data that were embedded in the baseband to achieve a dramatic reduction in file size/streaming bandwidth lay well below the recording's analog noise floor (footnote 3) (see "Amazing Grace' Spectral Analysis").

Some critics have complained that the limited word length used to encode data above the baseband Nyquist frequency of 22.05kHz or 24kHz is equivalent to lossy compression of those data. But as I explained in my 2014 website article, if you look at the spectra of music recordings, they all follow a self-similar characteristic with respect to increasing frequency, the content decreasing in amplitude up to 60kHz or so, when it blends into the analog noise floor. So if you remove the baseband data, the remaining ultrasonic content can be encoded with fewer bits. Only if you then decode the limited-word-length data at the full-scale baseband level could you consider the encoding lossy. But if the peak amplitude of the limited-word-length ultrasonic data is reduced to that in the original recording, you do preserve those data's full resolution above the original analog noise floor.

Case proved for the music origami aspect of MQA, I feel. However, the only way of testing the second claim—of MQA's correction of time-domain errors—is through listening.

Comparisons
I had sent MQA's Bob Stuart the 24/88.2 masters of some of my recordings, for him to produce MQA versions. When he DropBoxed the MQA versions to me, Stuart also loaned me some MQA-encoded hi-rez files that had been used in MQA's demonstrations at the 2016 Consumer Electronics Show, as well as a number of MQA-encoded FLAC files accompanied by the original PCM versions.

I began by listening to the MQA files without any comparisons, with the Meridian Prime, its firmware updated to decode MQA files, driving headphones or with its line outputs feeding the Pass Labs monoblocks. In his review of the Meridian Explorer2, Jim Austin wrote about what he heard when listening to MQA files: "that sense of intimacy and closeness—of almost exaggerated texture and timbre (exaggerated because recordings rarely capture it, and we rarely sit close enough to hear it in concert)—is apparently just what one would expect MQA's technical advantages to convey. . . . MQA has me excited about the future of recorded music."

The MQA files were varied in content—as well as Steely Dan's "Babylon Sisters," they covered a wide range of musics, ranging from Muddy Water's "My Home Is in the Delta" through Ella Fitzgerald and Louis Armstrong singing "They Can't Take That Away from Me," Van Morrison's original "Moondance," Dire Straits' "Sultans of Swing," some early 2L recordings of Carl Nielsen's piano music, Keith Jarrett's The Köln Concert and the Doors' "Riders on the Storm," to Britten's Hymn to the Virgin performed by Schola Cantorum, the second movement from the Guarneri String Quartet's performance of the Ravel Quartet, and Eiji Oue and the Minnesota Orchestra's Rite of Spring from Reference Recordings. Most had originally been recorded or transferred from the analog master at 96kHz, but the Ravel and Rite were originally sampled at 176.4kHz, the Britten at 352.8kHz, the Nielsen pieces at 44.1kHz.

Whatever the provenance, a consistent factor in my auditioning of the decoded MQA files was a sense of ease to the sound. High frequencies were in no way dulled, but the treble was consistently sweet. And there was a good sense of image depth even with the mono Ella and Louis recording.

My conclusion from these uncontrolled listening sessions was that MQA certainly doesn't damage the sound. Quite the opposite—the Prime sounded consistently sweeter than it had in the comparisons with the Ayre and Simaudio headphone amplifiers with regular PCM files. But comparisons of MQA files and the PCM originals would tell the complete story:

Ella and Louis: Fitzgerald's voice in the original had a slightly phlegmy edge; this edge was still there in the MQA version, but now I more readily marveled at what a great instrument she had.

Babylon Sisters: Comparing the MQA and PCM versions of this recording, I had difficulty coming to a conclusion. While the top octaves sounded sweeter with MQA, the bass was a little less well defined than with the 24/96 original. Though the metallic sound at the left of the stage in the intro was more generically clangy with the original, overall the track sounded a little less exciting with the MQA-encoded file. Interestingly, the MQA version of "Babylon Sisters" sounded pretty much identical to the DSD version, transcoded to 24/176.4 PCM, on the Prime.

The Rite of Spring: Although this has always been a reference-quality classical orchestral recording, comparisons were made difficult by the very varied nature of the scoring and the work's length. But in some places, such as the woodwind passage that starts around 1:20, the hall acoustic seemed better integrated with the images of the instruments with the MQA file.

The Köln Concert: The close-miked piano on this classic recording has always had a clangy quality. The clanginess was diminished with the MQA version, the piano's tonality sounding more believably that of a real instrument.

Amazing Grace: The first of two recordings of mine I used for my comparisons and for which Bob Stuart had prepared MQA versions, this arrangement by Eriks Esenvalds opens and closes with solo soprano, set against a choral vocalise. I've always been happy with the sound of the original 24/88.2 WAV file, but with the MQA version, Genna McAllister's angelic vocal line stands a little more forward from the choral halo, which itself sounds a little farther back than I'm used to. Overall, there was simply less ambiguity in the spatial relationships between the singers and the surrounding acoustic with the MQA version.

816jamqa.3.jpg

Water Night: The scoring of this choral work by contemporary composer Eric Whitacre is complex and occasionally dense. But with the MQA version, the inner voices were better differentiated. And as with "Amazing Grace," the relationships of each of the singers to each other and the surrounding space seemed better defined. The reverberation tails in the warmly supportive acoustic of St. Stephen's Catholic Church, in Portland, Oregon, faded cleanly into the room tone in both cases, but at one place in the recording the MQA version just sounded more real: About two seconds before the singers start, there is a very quiet noise toward the back of the choir. It sounds somewhat like a generic tick on the original WAV file, more like a sound made by a human being in a real space in the MQA version.

816jamqa.2.jpg

This reminded me of a comparison between an MQA-encoded recording and the original file that I'd heard at the 2016 CES. It was a live recording, and I'd been impressed at the very start of the track, even before the music began, by how the MQA version presented the sound of the hall with less ambiguity. It was as if my brain were having to do less work making sense of the stereo information to construct an internal model of the recorded acoustic.

Summing Up
After doing all of my formal comparisons, I subjected myself to a sort-of-blind test. I created an Audirvana playlist that randomly mixed MQA and non-MQA files, and pressed Play. I then went into my test lab, which is in the room next to the listening room, to begin measuring some of the products in the review queue. At irregular intervals I returned to the listening room and made a decision, MQA or non-MQA, before looking at the Prime's front panel to see what was playing. I scored four out of seven correct; though this is insufficient to prove formal identification, I feel that it is relevant information.

As well as the claim that MQA reduces file size while preserving the original hi-rez recording's ultrasonic spectrum, which my earlier work had shown to be correct, my comparisons of MQA-encoded hi-rez files with the PCM originals indicate that the improvement in sound quality conferred by the time-domain optimization of the entire ADC–storage–transmission–DAC chain is real. And third, despite the reduction in file size, MQA files, when decoded, tend to sound excellent (footnote 4). Will that be enough to ensure the format's success? Only if the record industry embraces it—and for more on that subject, see Jim Austin's interview with MQA's Spencer Chrislu, elsewhere in this issue.—John Atkinson



Footnote 1: See J. Robert Stuart and Peter Craven, "A Hierarchical Approach to Archiving and Distribution."

Footnote 2: Into Unknown Worlds.

Footnote 3: In his "Manufacturer's Comment" in the June issue, Bob Stuart wrote that the level at which MQA buries information from higher octaves "is not predetermined; it's responsive to the content. However, the burying level is completely stationary throughout every song or work. In JA's recording of 'Amazing Grace,' MQA buries the top-octave information (as broadly white noise) below the 20-bit level in the majority of the audioband. This does not mean that the channel is limited to 20 bits—the DAC still receives a 24-bit signal. It simply means, in this case, that MQA's effective noise floor is more than 5 bits below the (minimum 15-bit) noise floor of the original signal—a very healthy margin, and on a par with the very best converters."

Footnote 4: For more about MQA, including listening comments, see www.audiostream.com/content/mqa-reviewed. Note that I didn't read Michael Lavorgna's review before performing all my own auditioning and writing this report.

COMMENTS
mrvco's picture

A 4 out of 7 hit rate, by a pro golden ear even, isn't anywhere close to justifying my signing on to a proprietary, lossy, neoDRM format that requires end-to-end certification, licensing and royalty payments while requiring me to replace my digital gear and music collection.

Furthermore, with 4G LTE and a 150M+ home broadband connection already in place and getting faster and more performant all the time, the "bandwidth savings" are inconsequential to say the least.

Sorry MQA, but you're at least a decade late to the party.

drblank's picture

It's Lossless, not Lossy. MQA only works with FLAC and ALAC…..

mrvco's picture

My only experience listening to MQA was at CES this year and I certainly didn't hear anything that made me think "I gotta have that!!".... unlike numerous other rooms that truly impressed. Granted, this could have been due strictly to the Meridian gear that it was being played on (UltraDAC + DSP7200 speakers, if I'm not mistaken).

Regardless, with regards to whether MQA is actually lossless or not (and other claims made by MQA, such as reduced file sizes for audible comparable files), I'll refer to the level headed write-up from John Siau at Benchmark:

https://benchmarkmedia.com/blogs/application_notes/163302855-is-mqa-doa

Maybe I'm wrong and MQA is actually the cat's meow, but I'll need to 'hear' the evidence before I jump on this, the latest audio bandwagon. If MQA is at RMAF this year, then I can give MQA another listen.

crenca's picture

...As I will be there but given the history of MQA and audio shows it is likely to be more of the same (a lack of even rudimentary A/B and thus inconsequential).

I have read the RMAF this year is going to be a bit of a mess (lots of outdoor tents, etc.) because the hosting venue is in the middle of renovations - perhaps MQA can do something about he sound of trucks rumbling by... ;)

Archimago's picture

It's a hybrid. Baseband lossless to 22kHz or 24kHz. Lossy ultrasonic reconstruction of buried encoded "encapsulated" signal.

crenca's picture

As you note, MQA (taking it's self disclosure at face value - something which is difficult to do given the context of Bob-and-allies intentional obfuscating around DRM) is only "lossy" in the ultrasonic region. I have been thinking that "lossy" is bit of an unfair criticism of MQA even if it is technically accurate.

drblank's picture

is that the file size would be similar to that of Lossy, but it's Lossless. I think for streaming audio, it might be the way to go. If streaming services start offering this instead of regular Lossless, it will be a lot less bandwidth required for them to upload the stream and for us to download the stream. I think that alone would be worth it so it lightens the congestion of WiFi and/or Cellular data streaming.

Just because there's more bandwidth doesn't mean we don't need to shrink the file sizes. I think the objective is for MQA to be the defacto standard for Lossless streaming. Remember, the more people that get connected to streaming larger audio and video, the current bandwidth will eventually not be adequate to handle the ever increasing demands of the public..

Just because we are supposed to get 4G/LTE etc. doesn't mean we always get full bandwidth all of the time. Peak hours is where it starts to hiccup, especially in heavily populated areas during peak hours. That's why they have guys roaming around constantly checking sound quality, data transfer speeds. You know, the "Can you hear me know" guys that work for Verizon, T Mobile, etc. etc.

the more people that sign up for these streaming services, the more congestion it's going to put on existing systems, where they will run out of bandwidth to serve everyone.

Theoretically? YES reality? NO.

mrvco's picture

If broadband providers can't keep up with streaming audio now or in the near future, then they have far bigger problems since 70+% of peak traffic and 37+% of overall traffic is HD video traffic (migrating to UHD over time, requiring 25M minimum) from Netflix whose typical HD bit-rate starts where even 24/96 FLAC streaming leaves off.

Regardless, there is no reason to force me to buy a new DAC so Tidal can save on their storage and streaming costs when they support unfolding in software for mobile devices that don't (and won't for some time, if ever) have reference level DAC chips capable of decoding MQA.

If MQA simply supports unfolding for software players (e.g. Roon, HQP,layer, Tidal, etc.), then I'm happy to see how MQA fairs in the market.

BayStBroker's picture

I agree completely. At best it is a superior lossy format. Meanwhile it is such a complicated "concept" that I've spent the last year trying to understand it. In the end I assign it an almost zero chance of catching on. I mean, all of this complaining about file size falls flat for me. My 2 TB drives are now the size of a pack of playing cards. GB, TB, who cares? Faster transmission and more efficient storage are the solution to large file sizes. And no digital format seems likely to me to surpass DSD played over a good DAC. All of the energy being wasted on MQA could better be used to fuel the resuscitation of momentum for DSD. Unfortunately, Sony really messed up the launch of that TRULY superior format!

crenca's picture

...however, there is no reason to grant the intentional abuse of language/definitions by MQA and its allies - MQA is DRM straight up, all day every day.

Anton's picture

That top pic is awesome, your listening room looks like there's less clutter! The white fringe on the red table cloth is sharp.

:-P

Back on topic, a 4/7 hit rate seems a little low.

I would be interested to see if there was a way to keep reducing resolution on the other files until you could hit 7/7 consistently.

We've done completely amateurish comparisons between Rhapsody (MP3?) and Tidal Hi Fi in our local audio club and we sit and discuss as we switch, with a group success rate of 100%, same system, same computer, just different streaming service. (As I mention, full amateur, but it was surprisingly easy to accomplish!)

I am rigged for MQA once it hits Tidal. I wish they'd unleash the hounds!!!

Thanks for the report.

John Atkinson's picture
Anton wrote:
That top pic is awesome, your listening room looks like there's less clutter! The white fringe on the red table cloth is sharp.

It's the side chapel of the church where I made the choral recordings that I then had mastered with MQA for the comparisons and measurements.

Anton wrote:
Back on topic, a 4/7 hit rate seems a little low.

It was the Steely Dan track that I got wrong—twice. Without it I would have scored 4 out of 5.

John Atkinson
Editor, Stereophile

drblank's picture

why Tidal hasn't released it. First off, they only have Warner signed up and I believe they are STILL in the process of converting Warner's entire catalog. That takes time since they have millions of tracks to convert. BMG and Sony haven't signed up yet and I'm sure they are trying to convince them to do it.

Plus, Tidal isn't doing all that well in terms of cash flow. The rumors were that they were trying to sell to Samsung, but that fell through, and then other rumors of Apple buying them, but nothing has surfaced yet…

The problem is that Tidal, Spotify and others can't seem to turn a profit with streaming services, so its going to require a giant company like an Apple that doesn't rely solely on streaming services to hit profitability. Apple probably the best choice since they haven't had a loss in a VERY long time and they have deep pockets (more than anyone else) to be able to survive running a streaming service at a loss, even in a bad economy. I personally think they are just not charging enough and I'm not real sure people will keep their subscriptions if they raised the prices so they can hit profitability. Even Amazon had increased their Prime rates. I signed up and it was around $80 a year and they raised it to $100. It was still kinda worthwhile, but I still don't feel confident than any streaming service can survive at the rates they are currently charging. Just MY OPINION.

I tried Tidal and Deezer with Lossless streaming and I had issues with both either having buffering issues or just sounded horrible due to streaming issues on their end. Tidal had constant buffering and Deezer had a different problem with some tracks. So, for me? I'm holding out until they get their act together. I don't want to pay for a service where I'm listening to music and they have buffering issues.

Per's picture

Just a humble comment on Tidal, a service I have used a lot since the name was Wimp and always with highest quality - I even beta-tested the streaming FLAC when they introduced it. I have never had any issues with it and the audio quality is 99% of a "local FLAC" or even CD version. Done a couple of blind tests (B&W 800 series D2 and Pass labs) and it is almost impossible to distinguish what is Tidal and what isn't. I think they are doing a great job, I really they will survive; one way or another.

christophervalle's picture

I'll agree that 4 out of 7 correct is not that swaying, but I'll accept that you heard what you heard during the more formal comparison. I would hope to hear the difference for myself sometime, but so far this appears to be a technology that may whither on the vine. Apart from a few pieces like this one, that appear irregularly, the "news" part of MQA seems to be the same stale stuff that has been out there for quite a while. No update on Tidal, no catalog or timing information from Warner.

Also, JA, wasn't there a groundbreaking technology some years ago that promised to correct flaws in speakers? From Ray Kimber, maybe? If I recall correctly, it was a much heralded solution to a problem we didn't know we had (like the deblurring in MQA), got some press then disappeared forever.

CV

soundman45's picture

John I think based on your conclusion MQA is probably still a work in progress. Based on your listening tests it would probably be safe to say that MQA has about the same level of realism as a good DSD recording. I think where MQA will inevitably shine is in the streaming business. The ability to stream realistic 24/192 files to the listener in a smaller container is a big step forward. Whether they can get all the equipment manufacturers, recording studios and record labels on board is another story.

Anton's picture

Nicely stated.

tonykaz's picture

Hmm, I'd have liked it if you had a Proper Statue of Saint Anthony, Patron Saint of "Lost & Found" and a bit of incense burning. Seems appropriate to finding lost sound quality and loosing file size.

Nice seeing you posting, Tyll is doing a great work.

Anthony in Michigan

ps. I was born into Roman Catholicism, I discovered, later in my life, that Christ died an Orthodox Jew, seems he was never a Christian. Those Priests at Our Lady of Sorrows were also puzzled to contemplate this. btw, I though you Brits were all Anglican or is it Prebsaterian? ( never could tell the difference )

Anton's picture

Patron saint of lost causes!

I was never bothered by Jesus not being a Christian - that would make Him self-worshipping, which would make Him a political candidate, not a deity! :)

Anglicans are just Catholics gone bad who worship Henry VIII. It's a form of idolatry.

Presbyterians are people who can't see things right in front of their eyes. Amblyopians are people who can't see things that are far off.

There, all garbled!

tonykaz's picture

Ahhh, a kindred spirit, I give you applause & full marks! You have the makings of a darn good Audiophile.

I'd love to read your review of Fuse auditioning!

Tony in Michigan

John Atkinson's picture
tonykaz wrote:
I was born into Roman Catholicism, I discovered, later in my life, that Christ died an Orthodox Jew, seems he was never a Christian.

Christianity followed His death, its spread as a formal religion set in motion by St. Paul.

tonykaz wrote:
I though you Brits were all Anglican or is it [Presbyterian]? ( never could tell the difference)

I was raised Catholic (My mother's family were French). However, I walked away from it when I was around 13, when I was told that transubstantiation in the communion ceremony was not a metaphor, that the wafer and wine really did change into flesh and blood. It never did for me and, I suspect, not for anyone else.

John Atkinson
Editor, Stereophile

tonykaz's picture

I suppose we ex-catholics are having a bit of fun with our histories and life experiences.

A few years ago, I was delighted that our First Amendment allowed/empowered Christopher Hitchens to "publicly" share his philosophy on Religious matters.

I applaud you for allowing it.

The big headphone site does NOT allow freedom of expression.

Tony in Michigan

dalethorn's picture

Jesus, "the christ", died according to the text, as a sacrifice for which he was created ('begotten'), to appease the supreme creator. As I understand the writings from different religions and sects, sacrifices were mandated after the once-perfect people were forcibly removed from their garden of eden, and the Jesus sacrifice was ostensibly the culminating sacrifice event for the human race. It's possible to see the Jesus story as more or less the ultimate selfless act of a man who, despite his ultimate destiny, was created human so as to feel all of the pain that us humans feel, especially when abused and beat up on by our fellow humans. And so I understand it as an example to us, metaphorically or otherwise, to be of service to the world, and not be selfish.

tonykaz's picture

Are you presenting?, or perhaps suggesting a darn good 'politically correct' extrapolation?

God gave Moses the command: Do not kill!, then he told him and his band to kill everyone in the Promised Land. phew. ( except the young girls, which the killers could keep for their own purposes ).

I suspect that man created God in man's own image, not the way the Church Institutions present it. Men have always been creating their own gods. Constantine and his clever bunch of religion designers pulled off the Hat Trick, they created the franchise of getting their believers into Heaven, the simple Jews thought Paradise was Earthly ( and still do ). The Roman Catholic bunch also expanded their Menu to include Hell ( which our Modern Pope says: has no scriptural basis but he's from S.America, for gods sake ).

The study of the Dead Sea Scrolls is popping up in University classes, another facet of Scriptural perspective is now available for careful study and analysis.

I should mention that I am not a True Believer as defined by Eric Hoffer. I embrace science. My wife of 50 years is an Ordained Minister ( ultra True Believer ). We two are opposite sides of the same Coin.

I'll conclude with Ben Franklin ( no God for Ben ) by asking: Why did God give electricity to Ben Franklin ( of all people )? Why the hell didn't he give it to Moses. We could've had Focal Headphones & Cell phones three thousand years ago!

The God thing is rubbish.

Tony in Michigan

ps. politically correct 'rubbish' that we need to have your son die for

Anton's picture

Hi Fi is proof that God loves us and wants us to be happy.

dalethorn's picture

The Jesus example is about sacrifice, humility, and service. You may be lacking in one or more of those, which hinders your understanding. You need to learn to extrapolate the principles there to real life, rather than use scientific literalness as an excuse to avoid serving your fellow man. A wise man once said "He who knows he knows, knows nothing. But he who knows he knows of nothing, really knows." That's humility.

Anton's picture

Rumsfeld!

Reports that say that something hasn't happened are always interesting to me, because as we know, there are known knowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns – the ones we don't know we don't know. And if one looks throughout the history of our country and other free countries, it is the latter category that tend to be the difficult ones.

dalethorn's picture

The one I think that's most relevant here is to consider what a tiny slice of the electromagnetic spectrum we experience physically. Our instruments tell us how much more there is, and our knowledge of quantum physics suggests that we'll eventually get access to some things that conventional physics won't. In the meantime, to assert with feigned authority that "A wire is a wire for all audio purposes", declaring of course the 'proper' dimensions of the wire and the materials therein, seems specious and even arrogant.

Anton's picture

So....we can't measure the tiny quantum differences between wires, but their benefits can travel through our gear, into our speakers, and through the air to our ears and we can tell these differences?

I fall on both sides of this fight: I think 'wires' make a difference, but can't figure out why the hobby's journalists who measure all sorts of things on other gear won't try this process with 'wires.'

I am hopeful that, one day, 'wire' reviews will be like some speaker or cartridge measurements, and someone like JA III can comment along the lines of..."Given this 'wire's' impedance, capacitance, and inductance measures, it will likely perform best when used with (insert type of ancillary gear here.)"

We are already used to seeing impedance curves for speakers, efficiency, cartridge loading, etc. data, so why not 'wires?'

dalethorn's picture

Impedance curves were useful to me at one time, with speakers having a 'nominal' impedance of 4 ohms, with amps that had limited power. The actual impedance might drop as low as 2 ohms at some frequency, and a fuse might shut the amp down (if you were lucky). Today we see people having trouble with Sennheiser HD650 headphones, or some of the Beyerdynamics, when the impedance spikes around 100 hz, and the user is driving them with an underpowered portable amp. Opposite problem from the 2 to 4 ohm speaker.

jeffdyer's picture

We are already used to seeing impedance curves for speakers, efficiency, cartridge loading, etc. data, so why not 'wires?'

For the obvious reason. For any properly designed setup, provided that decent quality cables are used of reasonable length, there are no detectable differences to measure.

tonykaz's picture

I think you have me with this Sacrifice business, I look back on my life thinking that I've never had to sacrifice ( especially compared to the generations preceding me, going back thousands of years ), I won Life's Lottery!

Scientific studies, since the 1500s, especially since the 1950s, have successfully exposed the Superstitions that people like my lovely wife preach about. Worshiping religion has become a Social fabric much more than a belief system, people needing to be part of a 'good group of like minded people', ( a nice, safe group to congregate with ). Nationalism has become another religious belief system ( probably more popular than Jesus ).

Service, hmm, does spending the last year energizing the Bernie Sanders campaign count as service?, I've been called into the Battleground states of Ohio, Pennsylvania, Virginia, N.Carolina and Florida. I and my group are all Volunteers (unpaid). My wife would like me to provide her with considerably greater service but I'm refusing to be her personal assistant. I suppose that everyone could make Service a higher priority, all could probably do more than they do for the purpose of trying to improve society to a greater extent than they've done in the past.

As far as knowledge is concerned, I think its safe to say : "the more we know, the more we don't know". We're beginning to understand how the simple Acorn works, yet its difficult to understand how it has a Blueprint for an entire Forest.

You can have all the Humility you like, you can even go out of your way to recommend it, you might even display greater humility than anyone in your area. Some are justifiably proud of their personal humility. If God created Man as his greatest creation than it's probably not a good worshipful thing to say it isn't great.

Tony in Ohio

John Atkinson's picture
I have deleted all the subsequent posts concerning religious belief as being off-topic. It you wish to continue discussing this subject, our "Open Bar" forum is the appropriate place.

John Atkinson
Editor, Stereophile

tonykaz's picture

Certainly

Tony in Michigan

jphone's picture

The idea that Mr Atkinson may be recording on location and not projecting any religious affiliation escapes most of us I think. We see what we want to see.

tonykaz's picture

Very good point, I hadn't thought of it, I thought it was his home Altar setting for his Hifi gear.

I stand corrected and apologize.

Since you pointed this out, it seems obvious.

Thanks for writing.

Tony in Michigan

Anton's picture

Some of us saw a chance to goof around!

I should have also mentioned his apparently gargantuan living room!

eriks's picture

I love church architecture and acoustics, not to mention religious music from around the world and the past.

If you want to hear organs, where do you think most of them are??

It's not like we are children that need to be protected from possible government or corporate interference in our belief system. Well, I don't. I can shrug that off no matter what. Can't you?

Besides, Music is a tool of diversity and understanding. It is the beauty that exists in a culture that breaks down boundaries and gets us talking and understanding one another instead of being fearful or contemptuous of them.

Music good.

Regards,

Erik

Allen Fant's picture

Excellent discussion- guys. Back in the days when Christ roamed the Earth, there were many, who worshiped Idols.

Anton's picture

They stopped worshipping those idols as soon as Jesus rode in on His dinosaur.

Then, the Catholics put to death the idol worshippers and crushed their bones to make the ceramic for their statues of Jesus, the Virgin Mary, et al.

When I was a kid, the nuns would light candles and kneel in prayer before statues of the proper idols. It was great.

We should do an idol count on the pics in JA's blog entry!

dalethorn's picture

They still do. Back in the 90's, PBS interviewed a number of 7-year-olds from Russia, asking them many questions. One girl, when asked about the official policy against religion and how she felt about the 'god' question, replied that Americans have many gods, the almighty dollar chief of all.

jeffdyer's picture

The only true test of a system and the only test required is to record a square wave, play it back, and look at it in an oscilloscope.

A pure square wave contains every frequency in the spectrum. By looking at the roundness of the corners and overshoot it is easy to see whether the system works or not.

Anything else is pure speculative fantasy.

Archimago's picture

Of course:
"My conclusion from these uncontrolled listening sessions was that MQA certainly doesn't damage the sound."

After all it is a 24/44 file and takes up at least 50% more space than a standard 16/44 stream from Tidal. Not damaging the sound is at least a pre-requisite!

JA, are you comparing apples-to-apples here with the file size comparison? When you say "smaller even than the 16/44.1 version on the CD release", can you tell us what is the size of the FLAC compressed version of this 16/44.1 on the CD compared to the same FLAC compressed MQA (same FLAC settings of course)? The CD filesize is around 50% of MQA, right?

Also, can you give us some insight into what is accounted for by the MQA process? For example, when you submitted the hi-res file, what other info about the recording process did the MQA encoder need to perform the DSP magic for time alignment?

John Atkinson's picture
Archimago wrote:
When you say "smaller even than the 16/44.1 version on the CD release", can you tell us what is the size of the FLAC compressed version of this 16/44.1 on the CD compared to the same FLAC compressed MQA (same FLAC settings of course)? The CD filesize is around 50% of MQA, right?

I don't have a FLAC version of "Amazing Grace" but the ALAC version is 26.6MB compared with the uncompressed CD file's 55.7MB, the original 24/88k2 file's 169.5MB, and the MQA-encoded FLAC version's 51.5MB. Of course the MQA file is larger than the ALAC file because it is 24-bit data compared with the CD's 16-bit data.

Archimago wrote:
Also, can you give us some insight into what is accounted for by the MQA process? For example, when you submitted the hi-res file, what other info about the recording process did the MQA encoder need to perform the DSP magic for time alignment?

Your use of the semantically loaded word "magic" reveals your biases here. But to answer your question: As I used 3 pairs of microphones and 2 types of A/D converter to produce the mixdown—see the photos—as well as the mixdown I sent Bob Stuart each of the 3 mike-pair recordings, including an impulse response recording for each, and full details of the mix.

John Atkinson
Editor, Stereophile

Archimago's picture

Thank you for the response JA. Right. So if we take the ALAC version (and ALAC tends to compress poorer than FLAC level 8) as the base, then the MQA-FLAC is almost 2x larger (1.94x) as expected which I think is important to bring up when it comes to streaming and data utilization. Not only is there a difference because of 16-bit to 24-bit container, but many of us have found those last 8-bits highly uncompressible. (That's pretty significant. Imagine if my book-keeper say "Hey Arch, your expenses this year was about the same as last year!" but in fact was 1.94x the amount. Is that not the same as MQA being "roughly the same size" as CD?)

My use of "magic" is I believe consistent with the claims being made.

MQA is being advertised up to a level which it cannot meet and seems remarkable - ie. "magic", "unreal". As I asked in the previous blog post by MQA, they're spending a lot of time impressing upon us the time domain performance with all kinds of claims about accuracy (eg. so and so many feet of air...) yet there's really no way it can achieve that in real life. Reading between the lines, I do appreciate your use of "MQA is claimed to be able to compensate for the time-domain errors of both the original A/D converter used to make a recording and the D/A converter used to play it back."

But the comment:
"This results in the complete recording/playback chain having an impulse response equivalent to a few feet of air, and temporal resolution of the same form and order as that of the temporal sensitivity of the ear-brain."

... cannot be completely true because obviously the playback chain with MQA does not include the preamp, amplifier, and especially not the speakers. There is obviously no way for MQA to ensure ("authenticate") they can practically "deliver the sound of the studio" (one of Stuart's previous interview comments), much less ensure that kind of temporal response with actual listening. (MQA could of course say "that's what we meant - accurate only to the DAC output and the sound for any listener could be wildly different"; but that's certainly not what most audiophiles are expecting.)

Thank you also for the response on what was provided for the MQA encoding of your track. Good to know the kind of complex audio data provided to them. I do wonder though how many studios would be able to provide this level of detail for the encoding process especially for modern multitracked recordings! It would be truly "magic" if MQA can significantly "de-blur" music created without the meticulous information and actual track recordings.

AJ's picture

https://en.wikipedia.org/wiki/DVD-Audio

Lossless packing becomes MQA.

Does past predict the future of yet another "Hi Rez" packaging pitch to 70yr old aural olympians?
Stay tuned....

Always thought Holy Grail of audiophiles/studiophiles was "accuracy" to the "artists intent" (and other similar fantasies).
Confounded by how a "deblurred" remaster accomplishes this, assuming of course, the sound changes.

fmplayer's picture

At this stage, I understand that MQA is "a psychoacoustically determined DSP processing of hi res data combined with a lossy compression of the part exceeding CD quality, all embedded in the CD quality data" with the DSP processing aiming to "compensate for the time-domain errors of both the original A/D converter used to make a recording and the D/A converter used to play it back".
It is thus a complex, bundled 3 stage processing that probably cannot (except for Mr Stuart) be split into its 3 basic operations.

The DSP processing is performed only on the MQA file, not on the original file, which means that they are not identical per se. So, we are not comparing apples with apples sensu stricte.

Three points have to be checked :
1. The relevance of the DSP processing
2. The absence of negative consequences of the "origami" data arrangement on an original hi res file
3. The absence of negative consequences of the "origami" data arrangement on the CD quality data

This DSP processing is in my opinion controversial. I won't discuss the topic further, but just think of multiple A/D processors, one for each track (several musicians recording each in a separate studio is not an uncommon feature nowadays). I have hard times to admit that in a mastered mix of all these tracks, it would be possible to determine the characteristics of each A/D converter used. What was mixed cannot be unmixed, and what is relevant for one converter is not for another.
Psychoacoustics showed many ways to sonically improve things, and it is mastering engineers' job to use them with purpose to make great CDs.
All lossy formats rely on psychoacoustics findings for the most benign sonic result.

For the time-beeing, we have to trust Mr Stuart for all the 3 topics listed.

Without comprehensive testing and comparing, it is neither possible to be sure if the DSP processing is not aimed at masking the effects of the origami data arrangement, nor to be sure that the CD quality data remain unchanged for those who won't have a MQA decoder.

The MQA file is not (and cannot be) the same thing as the original file. It is a good engineering job for reducing file size, as mp3 is. Period.
Could it be better than the original ?

cgh's picture

My takeaway is two-fold: 7 is an odd-number. If the denominator was even this would look more like coin-flipping. Second, assuming it is coin-flipping (i.e., 50%), it still took prayer to get there.

When I think about political organizations and square-peg-round-hole R&D - or, rather, the consequences - MQA comes to mind. I could be wrong. An analogy would be pharma. You spend all this money to develop a drug for hypertension and it gets dropped in late stage trials. Not willing to take a loss you notice that during trials all these guys are running around with both high systolics and erections. So you make lemonade and market Viagra. I have the same issue in my life. I have a full team of PhDs that do nothing but R&D. I give them projects. I need to be good at seeing the future and knowing when to pull the plug. I still sometimes blow 6 months, though. Like I said, I could be wrong. I know nothing about the development of MQA. Just my gut after seeing the "hype machine" in action.

commsysman's picture

It seems to me that the real value of MQA could be in improving streaming quality.
When I listen to music from the internet, the typical classical station is transmitting only 128K MP3 files.
If MQA could become the streaming standard, it would certainly be a hell of an improvement over that.

crenca's picture

If true, it goes some way in explaining the strange phenomena that the MQA "hype machine" is.

Question: Since the "Audiophile press" is not *directly* involved - not a part of the R&D team itself, how do you explain their unabashed cheerleading? No doubt the real answer is complicated (i.e. financial dependence, friendships/networks that are too small for anything resembling unbiased critique, etc.) but even this does not seem to explain the all-in before even looking at the cards play by the audiophile press.

With MQA I have learned something important in the last year: there is a real need for a *consumer* oriented "audiophile press"...

cgh's picture

Crenca, I like John's write-up here (I always like John's work.) However,...

Robert Harley, editor of The Absolute Sound has referred to it [MQA] as "The most significant audio technology of my lifetime".[ Harley, Robert. "Master Quality Authenticated (MQA): The View From 30,000 Feet". The Absolute Sound. The Absolute Sound. Retrieved 11 May 2016.]

Editor John Atkinson writing in Stereophile magazine following the UK launch in December 2014 wrote "In almost 40 years of attending audio press events, only rarely have I come away feeling that I was present at the birth of a new world."[ Atkinson, John. "I've Heard the Future of Streaming: Meridian's MQA". Stereophile. Stereophile. Retrieved 11 May 2016]

The most significant ... of my lifetime? Birth of a new world? Hyperbolic, eh? These are some serious endorsements.

A project like this usually starts with a problem that one is looking to solve. Going back to abstracts from talks by MQA's designers prior to the launch the goal seems to be sound quality. From "A Hierarchical Approach to Archiving and Distribution" in the AES library:

"When recording, the ideal is to capture a performance so that the highest possible sound quality can be recovered from the archive. While an archive has no hard limit on the quantity of data assignable to that information, in distribution the data deliverable depends on application-specific factors such as storage, bandwidth or legacy compatibility. Recent interest in high-resolution digital audio has been accompanied by a trend to higher and higher sampling rates and bit depths, yet the sound quality improvements show diminishing returns and so fail to reconcile human auditory capability with the information capacity of the channel. By bringing together advances in sampling theory with recent findings in human auditory science, our approach aims to deliver extremely high sound quality through a hierarchical distribution chain where sample rate and bit depth can vary at each link but where the overall system is managed from end-to-end, including the converters. Our aim is an improved time/frequency balance in a high-performance chain whose errors, from the perspective of the human listener, are equivalent to no more than those introduced by sound traveling a short distance through air."

OK, so that last sentence lost me, but the rest sounds to me like they are trying to make it sound better.

Same guys, from a 2014 talk:

"We see increasing interest in High Resolution analogue and digital audio and in recordings employing higher sample rates or bit depths than CD. Yet this trend seems unstructured, and progress to be stalled in coding concepts established in the late 1990s.

In this lecture we hope to show how recent findings in neuroscience, perception and signal processing seem, at least to us, to point in a new direction — one which promises higher quality than ever — a different framework and direction for audio in the 21st century."

Again, the promise of higher quality. Nowhere does it appear to be a multi-year R&D effort to improve "streaming quality". My guess is these guys are always thinking about DSP and sound quality and MQA is the marketing realizing of years of disparate ideas coming together. That being said, the litmus test should be that we can hear it. That we get chances for A/B.

Archimago's picture

Great comment cgh.

Thanks for the references over the years. Indeed some hard to believe serious endorsements over the last year in the audiophile press! I don't even remember if I saw these kinds of comments back during the introduction of SACD and DVD-A. Surely that was the "birth of a new world" more so than this since for the first time, music was being released in decent volume beyond CD resolutions.

As you suggest, without a chance for A/B listening / testing, most aren't even sure what the quality of this is practically!

crenca's picture

You have me convinced that a bit of honest critique went in to your evaluation - it is not appear to be *mere* cheerleading/salesmanship.

Do you have an explanation of the "time alignment" aspect of MQA? Does it assume non-aligned speakers (most on the market) and what happens if you play an MQA file in a system with time aligned transducers (such as Vandersteen or Wilson speakers)? Or is this a fundamental confusion of two different things on my part?

John Atkinson's picture
crenca wrote:
You have me convinced that a bit of honest critique went in to your evaluation - it is not appear to be *mere* cheerleading/salesmanship.

Thank you. Next month I will have been writing about audio for 40 years, so I believe I have been getting better at it :-)

crenca wrote:
Do you have an explanation of the "time alignment" aspect of MQA? Does it assume non-aligned speakers (most on the market) and what happens if you play an MQA file in a system with time aligned transducers (such as Vandersteen or Wilson speakers)?

First, true time-aligned speakers are rare. Vandersteens are, Wilsons are not. (See the step responses in our speaker reviews.) Second, I conjecture that the improvement in sound quality due to MQA's "temporal deblurring" would be more audible on such speakers. However, my listening tests were performed with two pairs of speakers with conventional time-domain performance.

John Atkinson
Editor, Stereophile

AJ's picture
Quote:

Second, I conjecture that the improvement in sound quality due to MQA's "temporal deblurring" would be more audible on such speakers.

Dr Lesurf has an interesting analysis of the latest/greatest Hi-Rez packaging:
http://www.audiomisc.co.uk/MQA/origami/ThereAndBack.html
(Beware, he uses the term 'Magician' in the write up ;-) )

John Atkinson's picture
AJ wrote:
Dr Lesurf has an interesting analysis of the latest/greatest Hi-Rez packaging: www.audiomisc.co.uk/MQA/origami/ThereAndBack.html.

Thank you for the link. With typical ultrasonic music spectra, the presence of low-level aliasing products may not be an issue. See Keith Howard's article on the subject at www.stereophile.com/reference/104law/index.html.

John Atkinson
Editor, Stereophile

AJ's picture

Highly anecdotal, but to quote Mr Howard:

Quote:

..aliasing in the Faulkner downsampled file was at a low, probably inaudible level.
It will never work with source material having energetic high-frequency content, rock cymbals, foe example—the aliasing would be unacceptable—but for a range of other musical forms, it could be just the ticket.

Sounds like added spice to me. Nothing wrong with that, but lets call a spade a spade.
Did Mr Howard ever offer a follow up?
Another thought on aliasing:
https://benchmarkmedia.com/blogs/application_notes/163302855-is-mqa-doa

cgh's picture

Good article. Best explanation I've seen yet.

jimtavegia's picture

if I may?

I see your ORTF main mics, but are the others omnis to capture some additional natural room reverb/acoustic space? I am always interested in your recording projects and liked the last one from this group.

Thanks.

John Atkinson's picture
jimtavegia wrote:
I see your ORTF main mics, but are the others omnis to capture some additional natural room reverb/acoustic space?

With respect to the furthest-away pair of DPA omnis, yes, Jim, but the front, widely spaced pair of DPA omnis is actually the main pickup, with the ORTF pair of Neumann M147s to give stability to the center image. You can find a discussion of this technique in my 2011 lecture to the AES at www.stereophile.com/content/2011-richard-c-heyser-memorial-lecture-where-did-negative-frequencies-go-case-study-1-record.

Mike preamps were all low-noise Millennia Media HV-3s and the main A/D converter was an Ayre QA-9, with a Metric Halo 2882 slaved to it via AES/EBU.

John Atkinson
Editor, Stereophile

music or sound's picture

A lot of discussion about MQA is about file structure, lossyness of compression etc..MQA states that the major improvement in sound quality is about time domain especially deblurring . I have a hard "time" understanding this. Any single microphone has a different time signature already by having a specific distance to the sound source and then all the technical variations like microphone itself, amp, cable, AD, and mix and master. Of course there are minimalistic recordings with only 2 microphones but these are rare exceptions (and the ones I have I like alot). Also reproduction is diffucult to get time coherent (time aligned speakers are only really alligned in one point in space). Full range drivers (like most headphones) are normally much more time coherent. So how should that deblurring work?

Anton's picture

I hope there is further commentary about your inquiry!

Gorm's picture

Another new format. Great, but does the real world care. I may, we'll see, but I and folks on this forum are not the "real world". Proof: My dedicated listening room was carefully set up with pretty exotic equipment for which I could have bought a few new BMW's. So what? Well I have had many dozens of the best musicians and engineers on the BC west coast in that room, many with their latest CD projects. I love to play them those very CD's after cleaning with L'Art Du Son. They are suitably impressed. BUT only a few of them even knew about SACD, which by now has mostly come and gone. Will anyone but us loonies ever care about yet another, soon to be obsolete format. BTW I still do love my good vinyl and so do the musicians. Just Sayin'.

DCT's picture

...for a long time I have suspected that the sound quality from a CD was influenced more by the implementation, not the theory. We have all experienced that some CDs just sound better than others. Some of the best sounding CDs I own are the later recordings of Steely Dan. Is it possible that the reason JA was fooled by Babylon Sisters was simply that it was encoded well in the first place?

I know there are a lot of factors in the recording/mastering process that affect the final outcome, but could it be as simple as some weren't digitally encoded well? Isn't it possible that some A/D conversion just doesn't play well with some D/A conversion? The one thing about MQA that intrigues me the most is that it's an end-to-end solution where the files can be decoded precisely as they were encoded. I know that is probably nothing more than a layman's viewpoint, but, at the very least, we're talking about about encoding the original masters using the latest technology with an end-to-end solution and 35+ years of experience in the differences in mastering digital files. Am I being naive?

And, as others have said, I believe that the greatest benefits will come through streaming. If MQA gets the traction it needs and a broad catalog of content becomes available through Tidal (for instance), why wouldn't I go that direction if everything sounds at least as good as those great Steely Dan CDs? After all, I would never to be able to buy all of the CDs that I might want even if they all did sound great.

amazme1's picture

MQA has been around since it was demonstrated by Meridian Audio in 2014. Hardware and software solutions have been released. Many companies have committed to support it. But where is the music? Conversion of a few boutique vender tracks is meaningless. Unless Apple, Tidal, Amazon. Spotify and other big services convert, it will just continue hang around and be discussed. Show me the music.

adamdea's picture

I recommend taking a 24/96 flac file (eg one of the test files from 2L also available in MQA) and converting it to 16/96. Then compare with the size of the MQA file. Note that it is acknowledged in the MQA patent documentation that this is adequate to carry all musical information.

Now ask yourself why there is any need for MQA to be a format. This is distinct from the "deblurring" process which, if it is of any real use, can be applied to any FLAC file. Is MQA necessary to enable hi rez files to be streamed?

Next question. Whatever happened to the overwhelming need for all of us to have dsd?

Final question: having regard to the speed stablity measurements for any turntable you can lay your hands on, is it possible that reducing the "time blur" of a digital encoding and replay system to less than that of 10m of air will then make the digital system sound more like a turntable.

Actually I lied here's another one: ignoring the interaural time delay sensitivity of 7us (which can demonstrably be reproduced by 16/44), is there any other psychoacoustic evidence of human hearing achieving time resolution (eg gap detection, duration detection etc)less than 1ms?

Doctor Fine's picture

So glad that MQA is focusing attention on the blur around notes which normally occurs with brutal honesty whilst using the typical over etched playback systems preferred by many nowadays.
I became convinced twenty years ago the biggest gain I could wrest from my personal systems would be to spend more effort finding ways to emphasize timing clarity. By using four piece speaker arrays with speaker placement to get the timing delivery "right." Vandersteen and Kef come to mind as leaders in this area but you can make huge improvements on your own by setting up speakers that truly act as "one voice." Time alignment matters a LOT.
In fact I have long been of the opinion that there is greater listening enjoyment in rooms with time aligned speaker arrays and acoustic treatment "tuning" to remove room smear than there is enjoyment gained from higher and higher rez source improvements.
In other words Internet radio at 128k can be more involving than an SACD on my buddies systems because I have worked hard to get rid of the smear and they haven't.
It seems MQA is finally underscoring how much more pleasure one gets from loss of the smear than simply playing the endless game of chasing higher and higher resolutions.
The fact that MQA can fold back the higher rez information and cram more detail in a small file size is simply a "nice" improvement.
It won't do a thing for your existing recordings while fixing the room and fixing the speakers and amplification chain WILL pay a dividend on your existing collection of recordings long ago paid for...
Just saying.
I told you so.