Article: MQA: A Review of controversies, concerns, and cautions

[ednaz]

Watching the arguments of what's kept versus thrown away, what's real and what's invented, is it debarring or blurring, is it just upsampling, wait is that noise, brings to mind something from another domain - photography.

 

When printing digital photographs at display sizes - 16x20 inches, 20x30 inches and larger - professional printers, the type that would print images for a gallery or museum show, do a couple of tricks to every image, just before printing. (Learned these working for a famous NYC fine art printer.)

 

First, they apply an unsharp mask to increase the apparent sharpness (de-blurring), which paradoxically works by applying a mildly blurred image as a mask on to the original image. De-blurring by adding a mask of blurring. It raises the apparent sharpness of the image. Done well, it's not noticeable. Done poorly, you get visible halos in the image. Note that even done well, there are halos - the unsharp image absolutely makes them, but they're below your ability to see them - a pixel or two wide. (I learned to do this in film days. Much easier in digital.)

 

Second, they add noise to the image. Everyone evaluates digital sensors based on their ability to produce an image free of digital noise... but completely noise free images look odd. In large areas with no detail - sky, a car fender, still water - they look artificial and plastic. The printer uses one of a number of techniques to generate digital noise that's similar to film grain, and blends it into the image. The size and frequencies of the noise are based on the size of the final print. Again, the goal is to have it be there and effective but not noticeable. (When I show people prints where I've done this, they have a hard time detecting it, even after being told what to look for.) That added noise does three things. It makes the image seem more real, and less digital. It reduces the visibility of actual digital noise from the sensor. And, it also increases the apparent sharpness of the image.

 

In photography - which is about capturing the most accurate renditions of light and color with a recording device and then reproducing them for viewing - adding information that was never there to begin with increases the perception of it being a more accurate and sharply rendered image of the real world.

 

I imagine that the same types of tricks, applied to audio files, may improve the apparent accuracy and crispness of the rendering of recorded sounds. After all, we see and hear with our brains, not our eyes and ears.

[ednaz]

2 hours ago, mansr said:

You make a good point. However, our visual and auditory perception work in very different ways. Just consider that 25 frames per second is enough to produce a convincing video while audio requires a sample rate 1000 times higher to get anywhere close. We are far more sensitive to distortions in sound than in images. Audio with as much distortion as a good JPEG image is unlistenable. Tricks that work well for imaging and video rarely transfer to the audio domain.

All that scientific fact about moving images (I was talking about stills) ignores what I see about MQA. People with great ears (I was a union card holding musician until I was 30) talk about how MQA has more reality in the sense of environment. Which, given the de-blurring techniques, and noise feedback... makes a lot of sense.

 

Detecting distortions... all those image print techniques are based on taking advantage of our perceptions. I think MQA takes advantage of our perceptions. Not reality. Brains hear. They function at a pretty damn low sample rate.

 

Incidentally, I'm not talking about JPEG. Not even 100% JPG (although if you're willing to put up a big bunch of money I'll let you try to prove to me that you can ID JPG distortions.)  I'm talking about raw images, or 16 bit TIFFS, in color spaces way beyond Adobe RGB. Really, assumptions make... you finish it. I'm also not talking about Joe from the Street looking at images, I'm talking about high name recognition photographers.

BTW, I've spent my last few years building real time environments for visualizing brain activity in multiple types of visualization (fPET, fMRI, ERP) technologies overlaid... We may sample sound frequently but we don't use it. Your brain's activity sets early in a listening (or viewing) session and rolls it forward. Brains are lazy. Like humans.

 

And I suppose I'm assuming an ability to grasp analogies. I could well be wrong. Most of my work is based on cross domain analogies, but not everyone can do that.

[ednaz]

JPG = MP3

 

RAW = DSD

 

TIFF = FLAC

[ednaz]

3 hours ago, mansr said:

We know MQA messes with the phase of the signal. There are also hints at subtle EQ and trickery with the stereo spread. If you like those gimmicks, that's fine. Just don't foist them on everybody else. The noise MQA adds has nothing to do with perception. Most likely, the purpose is to mask the nasty artefacts of the MQA process, not from our ears, to which they are inaudible, but from measuring equipment.

 

You might be surprised by the outcome. Luckily for you, I'm not going to put up "a big bunch of money" towards such a challenge.

 

That's getting dangerously close to an insult. Watch your step.

"Watch your step." What kind of comment is that? Lovely.

 

Not an insult at all, but a statement of fact. Most people don't do cross-analogy thinking very well. After 35 years of leading teams in neuro-science, computer code reverse engineering, photography, drug discovery, entity analytics, cryptography, human systems analysis, and more, I think I have a good perspective on that. There's a well documented phenomenon of "expert blind spots" - the deeper an expert someone becomes, the more certain they are about every aspect of their discipline. I'm a professional "dumb question" asker. Fun way to make a living, never bored. Particularly for a musician and theater major.

 

People claiming they can detect jpg vs other file captures remind me of people who say they can always tell lossy compressed music files from non-compressed. I can with a lot of music, but when you get Alabama Shakes running a DR of 3... can't any more. I think that may be part of what's going on in the MQA arguments, and is a variable I can't remember being explored. People say that sometimes they sound better, sometimes just not worse, sometimes worse.  

 

Wouldn't it be interesting if, instead of challenging their hearing or expertise, someone tried to understand it? Took awhile before someone noticed that the volume levels of files, and pitch, influenced how people heard them.

 

I've long wondered if DR=3 versus DR=15 might be part of that. Alabama Shakes at high bit MP3 doesn't sound much different to me than 24/96. Are people arguing about MQA missing a GIGO problem?

 

[ednaz]

1 hour ago, botrytis said:

Manufacturers, except a few, are very agnostic. If they see something that a buyer wants, they will add it. I don't think it is anything more than that.

I certainly wouldn't go out of the way for MQA. The little bit of testing I tried (low patience level) led me to think it did seem to make a difference with some music - at least in what I heard. Music where I thought, OK, that's a little better was: music with a lot of spatial information, like live albums where you can hear the venue, music with a lot of dynamic range, combos and not orchestras. All that on headphones. But not a lot, and not consistently. Made me think that part of what it does is upsampling with a little tweak of spatial reverb. Interesting that the filter post-rings.

 

What difference I thought was there was less than what a slight upgrade in DAC would beat - if I had an incremental dollar I'd buy a dollar of incremental DAC performance.

[ednaz]

7 minutes ago, Archimago said:

 

 

The issue is not simply about GIGO. It is that MQA processing changes the sound with distortions that would not have been in the original high resolution master. This file format both adds anomalies (errors of commission) and is incapable of "containing" all that was fed into it (errors of omission).

I'm a process guy. I can get better performance out of people than I could ever give myself. There's a whole profession of that. Also helps to be good at exotic math.

 

Your last paragraph is exactly my point when I compared to photography. I make photographs feel more real, and more natural, by adding distortions that aren't there in the original image. Some it is adding artifacts and noise. Some of it is excluding information. The image is qualitatively improved by quantitatively degrading it.

 

When I read comments from people who like MQA and think it improves things, and then I see the data you presented, that's what comes to mind. Your examples (or maybe it was in one of the articles linked) of a DAC that takes the pitch of A up a bit higher (welcome to the 1960s pitch wars), of the files being a bit louder, of noise showing up quantitatively that isn't there in a non-MQA file, and the filter being limited to post-ringing, all felt to me like engineering for psycho-acoustics and not accuracy.

 

That's why the McGill study will be interesting.

 

[ednaz]

I didn't invent this. It's standard practice among fine art photography printers, like Duggal Imaging in NYC and Nash Editions in CA. Has been for years (I apprenticed for a couple months at a couple of printers back in 2001 just to learn technique, and those guys had been doing it since professional digital cameras were 3 megapixels.)

 

The whole process of sharpening is  completely about adding artifacts, and that's been done ever since there was photography and a desire to create the impression of sharpness.

 

The brain sees things, not the eyes. Every one of those techniques is about changing how the brain perceives things. The same is true about sound - the ears capture but the brain hears. Hence psychoacoustics.

[ednaz]

48 minutes ago, maxijazz said:

I don’t mind preference of others to be “cheated” to their liking (by “beautifying” music reproduction).

 

I demand “raw” music (lossless, bit perfect) for myself in a format, so I can “modify” it, if I am in a mood or need, to my liking. 

 

After modifications were already applied to source (in order to “cheat” statistically  average, typical taste), it is very hard, sometimes impossible, to undo them by consumer. And audiophile herds demand more than average or typical consumer.

You do realize that most studio albums where some performers were in soundproof booths have reverb added? I've heard the raw tapes (a big part of my photography was for jazz and blues musicians for CDs and PR shots) in the studio. "Dry" sax or trumpet doesn't sound pretty.  I've watched the sound engineer add slightly different reverb to different instruments because just adding it overall sounds artificial.  And that's just one of the normal things done in the recording and production process.

I think the only place you'll actually get raw music is in the performance itself. And, most of what's done in production is to make it feel more real and more alive. Psychoacoustics is a real thing.

[ednaz]

Just now, miguelito said:

Very true. And we often are firstly drawn to over-sharpened, over saturated images - and one can similarly characterize this in sound. But all those artifacts get old because IMHO they don’t represent reality.

 

Exactly. The whole HDR trend in photography is the visual equivalent of raising the pitch and volume and emphasizing the midrange in audio. But, all of that done subtly is there in every professionally printed image you see, the same way that production of music tweaks sound to be more appealing. Even guys like Jay Maisel, who shoots JPG and claims he doesn't do any post processing... well, HE doesn't do his printing, and that's where it happens. Other than bootleg concert tapes, what we hear can be very much the result of artful post processing.

[ednaz]

8 minutes ago, Rt66indierock said:

 

You got the wrong guy. 1985 Ping Eye 2 irons with the original square grooves identified by a raised pat number and others pending in the cavity. These are grandfathered and still legal for me to play in USGA events except the US Open. They have the WRX leading edge grind and were retumbled a slightly darker color with black paint fill instead of white. Lie and loft are custom fit and adjusted by the factory. Shafts are new Dynamic Gold without seams. Grips are old school Royal V Sandwrap grips ribbed.

 

And no the new stuff is not better. Don't get me started on putters and metal woods.

But, the real question is, how do they SOUND.