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MQA fracas at RMAF 2018

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DimitryZ said:
Y
Your assessment of MQA as a "scam" is both wrong and unhinged. Fact: It streams at 3.7 factor compression. Fact: many audiophiles find its' sound excellent. That is an achievement.
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Fact: I haven't said MQA is a "scam".

Fact: Other methods can compress the data to the same extent *without* changing the musical content or needing any change to the equipment required by the end-user.
 
adamdea said:
So, in summary
V.1 it’s not lossy
V.2 it’s not a bug, it’s a feature.
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In information theory terms it is 'lossy' because the output will differ from the input in systematic ways. Evidenced by the anharmonic aliasis which weren't in the source. This represents a form of many-to-one distortion. Whether that matters to a listener is another issue. Note that MQA long ago stopped claiming it was 'lossless' so this point doesn seem to be contentious.

It is a 'feature' in the sense that it seems to be about the only part of what they say which might make their patents contain a genuinely 'new thing'. Other than that, they seem to me to be essentially "HDCD on stilts".
 
misterdog said:
I'ts very quiet on here with Dimitry on blocked, so quiet I can here the music.

Is he still promoting 8 Track MQA as the future for humanity ?
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I didn't know you could 'block' someone so as to avoid seeing them go round the same irrelevant loops again and again. In general I'd not do this, but can you point me at how to do it? As it is I've got to mainly skipping his predictable repeat loops.
 
Click in their avatar and select "ignore". In this case, ignorance really is bliss.

Edit: Too late.
 
Interesting as that makes me wonder if 'ignorance' has a negative value in some cases rather than being a null. i.e. as in a negative of a negative is positive... :)
 
Jim Audiomisc said:
Interesting as that makes me wonder if 'ignorance' has a negative value in some cases rather than being a null. i.e. as in a negative of a negative is positive... :)
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Positively superb, especially as I seem to have a warning from the mods for speaking truth to the *****. You've done it much better though.
 
DimitryZ said:
In order to claim that there is NO ringing on CDs one must have a special CD made that has a series of impulses as the input signal. Then one would examine the digital data on the CD to see if there is or there isn't ringing evident. If filtering was used in the creation process and those filters were linear phase type, they will add pre-ringing to the signal by definition. You can claim you wont' hear it because it's "in the noise" or it is at very high frequencies, but it is there.
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This makes no sense. Why would you create a CD with impulses to see if there is ringing ? No one listens to impulse responses. An impulse response is a signal used only in the design of a filter, and not in its use. It does not occur on CD's or in nature. It is a "false" signal in music. It just does not occur.

Again, there is no pre-ringing in CD's. A CD is a band limited signal. The mastering process will not produce CD's with ringing. If ringing was there, you would see it in the spectral plot - as per Hifi News who provide spectral plots of downloads that they review.

DimitryZ said:
Since analog waveform has to be low pass filtered to be converted by an ADC with Nyquist compliance, and since most of the filters used in professional audio recording are linear phase, high order ringy-type , each sharp waveform will have characteristic ripple preceding it (for a linear phase filter you prefer) and this will be imbedded in the digital data. On complex sound, this ripple will fold into surrounding waves, much like the ripple from a thrown stone is hard to see and identify in rough seas-the surrounding waves are larger.
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The ADC's of today have such a high sample rate (at least 192kHz output sample rate) that there is no energy at or near the nyquist rate (assumes filter cut off near here), hence there is NO ringing.

There is no ringing - you keep on making false claims about CD and the mastering process. Why ?

When you state on complex sounds the ripple will unfold to the surrounding waves, this is another false statement. A Linear Time Invariant system, which is what LPCM, and CD is, does not behave like this.

So, not only have you made a false statement about ringing being on CD's, you have also made another false statement about ringing affecting the surrounding wave like a ripple.

The ringing event is finite and is half the length of the filter, and when it occurs is always small in amplitude. The only time it occurs is when the filter processes energy at the cut off frequency. All CD's and the mastering process ensures that this does not occur.

DimitryZ said:
You MUST understand that the filter ringing is a TRANSIENT phenomena and is only clearly evident in the time domain (like a graph of amplitude vs. time) or in very carefully done frequency domain transform (not all). It can't be identified in the power spectral density graph, unless the "music" is a series of impulses only. In an averaged frequency domain representation (i.e., the content spectrum), ringing is entirely invisible as it is a lower amplitude than the main signal. It can be seen as increased noise, but probably requires specialized test methods to be isolated.
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Regardless if the ringing is a transient phenomenon, it is ALWAYS present in the spectrum if it is present in the time domain. That is how FFT's work. The filter ringing is at the cut off frequency of the filter, so if it is present, you will see a blip on the spectrum at this frequency, it is NOT embedded in the remaining spectrum. Stating that ringing is invisible is a false statement.

Also, you made the claim that CD's have ringing, and did not provide evidence of which CD's do have ringing. Now you are stating that ringing is embedded in the CD which cannot be seen in the frequency domain, but can be seen in the time domain. You are continually making false statements, and changing them when challenged, and never provide evidence. Why ?

Regards,
Shadders.
 
But I have to add, without the output of DimintryZzzzzzz, or rather replies to him, I would have not known in so much detail just how shit MQA is. Thank you, all. And now anyone who googles MQA, this well argued thread is sure to appear.
 
I was looking at the spectrum of some later Hendrix recordings and they are follow a smooth curve to 60dB down at 15kHz and brickwalled just above that. Electronically generated and digitally recorded music goes up further, but rarely very far unless as a result of extreme compression and digital clipping. Does faithful delivery of ultrasonics help much with the latter case?
 
MQA claim on their website that: MQA reveals every detail of the original recording.

That is patently untrue as it is a lossy format.

I have just reported them to the ASA (Advertising Standards Authority) . It would be helpful if others were to follow my lead.

Here is the ASA website (making a complaint is easy):

https://www.asa.org.uk/make-a-complaint.html

And here's the MQA site making unjustifiable claims:

http://www.mqa.co.uk/

Do it!
 
I am not sure why the Audiophile "press" have not questioned the validity/quality/necessity of MQA.

Then again I guess it helps them as it is something new to write/talk about.

I watched a YouTube video recently of Bob Stuart blathering on about the technology. Not once did the interviewer question him.
 
FWIW I doubt anyone will get a useful response from the ASA. They are essentially ad-men, not expert in anything else. Their day-job is to put lipstick onto pigs... :)

So far as I can tell, some in the 'press' have simply decided to ignore MQA and assume it will go away... That's the kind of feedback I've got from talking to a few people, anyway. Others may in due time have something more to say.

TBH You'd be better off writing to the mags and asking them to challenge and write about MQA. Editors do notice letters, and enough of them can pursuade them that readers will want an article on an issue.
 
Robby said:
I am not sure why the Audiophile "press" have not questioned the validity/quality/necessity of MQA.

Then again I guess it helps them as it is something new to write/talk about.

I watched a YouTube video recently of Bob Stuart blathering on about the technology. Not once did the interviewer question him.
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I think it is because Bob Stuart has a lot of credits in the industry.
The biggest problem with MQA is that it tries to solve a ringing problem that was valid in the 60s, with a DRM approach that was less frowned upon in the 80s, using a file format that was valid up to 10 years ago.
It's a bit like a car manufactorer releasing a car that is finally capable of taking on the dreaded Ford model T.

Most of the audiophile press dates from the same era as well, and so they story makes sense to them.
 
Tin said:
I think it is because Bob Stuart has a lot of credits in the industry.
The biggest problem with MQA is that it tries to solve a ringing problem that was valid in the 60s
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I agree with the first comment. I also still hold Bob Stuart and Peter Craven in high regard as they've done a lot of good work and produced some excellent products. (I still love the 500 series DAC for example, and regret it won't do high-rate/res.)

The problem is that a good 'track record' doesn't ensure you can't make mistakes or go off in the wrong direction if you get too excited by your own ideas.

The 'ringing' problem for playback essentially vanishes once you use higher sampling rates. Because;

a) there is 3/5ths of SFA up in the region where any 'ringing' is likely to arise with high rate material.

b) you probably can't hear it anyway - either because of yer ears, or the speakers, etc, you use.

And as has been pointed out, real music isn't a series of isolated impulse functions which are a mathematical fiction anyway in the real world.

For me, the real advantage of high sample rate is to shove these problems well above where you'd hear them. And my personal view is that 96k is fine and gives bags of 'elbow room'. Then add noise shaping if you want smaller files, etc. Jobs a good'un.
 
Jim Audiomisc said:
FWIW I doubt anyone will get a useful response from the ASA. They are essentially ad-men, not expert in anything else. Their day-job is to put lipstick onto pigs... :)

So far as I can tell, some in the 'press' have simply decided to ignore MQA and assume it will go away... That's the kind of feedback I've got from talking to a few people, anyway. Others may in due time have something more to say.
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That's not an excuse not to put in a complaint to the ASA, especially with your expertise in the area. Two minutes. Put your time where your mouth is, and make sure MQA, with its false claims, goes away, without relying on rumour.
 
Emlin said:
That's not an excuse not to put in a complaint to the ASA, especially with your expertise in the area. Two minutes. Put your time where your mouth is, and make sure MQA, with its false claims, goes away, without relying on rumour.
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I'm not really the person for that in this case because my concerns and arguments are about the engineering and science of what their patents say they do. Their *adverts* are something else if they make claims of a more sweeping kind. And I'm not trying to 'stop' MQA because my concerns are:

1) To ensure people are well informed about the technical side. So they can make informed choices.

2) Know there are alternatives which may well make more sense or be preferred

3) We keep *choice*. My only worry here is the risk we may get into an 'MQA only' or 'MQA tax' situation in the future. But we aren't there at present.

Objecting to the ASA may well be a route others think useful to take. Personally, I think they are chocolate teapots, and not equipped to assess any 'technical' argument. You only have to look at other old rulings WRT other issues to see this. But if others want to raise objections with the ASA I'm happy if things I've said help.

That said, I don't actually recall seeing any detaied adverts for MQA. Just patents, 'papers'. etc. i.e. not paid-for advertising in UK magazines or newspapers that makes claims I could say were 'false'.
 
They have been very careful in their own (very few adverts) and let magazine editorials make the false claims. They just failed to correct the errors.
 
Jim Audiomisc said:
I'm not really the person for that in this case because my concerns and arguments are about the engineering and science of what their patents say they do. Their *adverts* are something else if they make claims of a more sweeping kind. And I'm not trying to 'stop' MQA because my concerns are:

1) To ensure people are well informed about the technical side. So they can make informed choices.

2) Know there are alternatives which may well make more sense or be preferred

3) We keep *choice*. My only worry here is the risk we may get into an 'MQA only' or 'MQA tax' situation in the future. But we aren't there at present.

Objecting to the ASA may well be a route others think useful to take. Personally, I think they are chocolate teapots, and not equipped to assess any 'technical' argument. You only have to look at other old rulings WRT other issues to see this. But if others want to raise objections with the ASA I'm happy if things I've said help.

That said, I don't actually recall seeing any detaied adverts for MQA. Just patents, 'papers'. etc. i.e. not paid-for advertising in UK magazines or newspapers that makes claims I could say were 'false'.
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To counter a couple of your points:

MQA home page says: "MQA reveals every detail of the original recording". Are you willing to go along with that? If so, you disagree with your own statement that you want to ensure people are well informed about the technical side. So they can make informed choices.


If you allow MQA to spew out their guff without challenging it, you are complicit with their duplicity.

The ASA route may not work, but it'll only take a few moments of your time. And you have nothing to lose apart from those few moments. So why not?
 
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