[Gringo]

  @Gringo , try to do something about how you quote. it's close to impossible to understand who's talking.
 
 
MQA offers something, time will tell if people want it. now the entire purpose of the format is to make files that can send smaller resolution when the streaming speed is limited. please guys don't go creating another white whale. it's not a superior format, it's not doing more than highres, it will not sound magically superior to anything.  the purpose of the format is the ability to scale down, not up!!!!!!

Sorry, I will try and do better, please accept my apologies
 
From what I have read it is not doing anything more than highres other than rectifying some artefacts that recording studio DAC's introduced in the past and some compensation for "Temporal Blur" but I have no idea how this is achieved or in fact possible but MQA seem to think it is. The file size is significantly smaller when transferred but is restored to its original bit accurate format other than some of the random 0's and 1's below the noise floor. If this all pans out, (big if), then very superior to MP3 and possible slight improvement on Highres, (but very debateable)
 
If my understanding is correct the only "smaller resolution"  aspect is again only in respect to the data below the noise floor
 
Totally agree with the doubt about if people will actually want it.

 

[RRod]

  If my understanding is correct the only "smaller resolution"  aspect is again only in respect to the data below the noise floor
 

 
I do find it slightly annoying that all of a sudden "below the noise floor" is being used to justify delivery of a hi-res format, while at the same time hi-res advocates will assure you that you need 24-bits, even though the differences between it and 16-bits are well below the noise floor of any actual room in which I've ever listened to music at high volumes. It's also interesting to see that delivery bandwidth suddenly matters, even though the same people will often tout how streaming speeds are perfectly adequate for hi-res FLAC streaming as a "why not" justification for higher rates/bits.
 
The main issue of course is that none of this technical wizardry will compel record labels to release actual good masters, so I guess we'll all be enjoying hi-resolution brickwalled albums soon enough. \o/

 

[Gringo]

I do find it slightly annoying that all of a sudden "below the noise floor" is being used to justify delivery of a hi-res format, while at the same time hi-res advocates will assure you that you need 24-bits, even though the differences between it and 16-bits are well below the noise floor of any actual room in which I've ever listened to music at high volumes. It's also interesting to see that delivery bandwidth suddenly matters, even though the same people will often tout how streaming speeds are perfectly adequate for hi-res FLAC streaming as a "why not" justification for higher rates/bits.

The main issue of course is that none of this technical wizardry will compel record labels to release actual good masters, so I guess we'll all be enjoying hi-resolution brickwalled albums soon enough. \o/

1) please excuse my ignorance and I would be very greatful if you or anyone else on the forum could enlighten me - what role do the random 0's and 1's below the noise floor contribute to the actual music that we hear? I had always been lead to believe that are merely random and well below the hearing threshold. If they have no discernible impact then I am not bothered about the area they occupy being temporarily used to store higher resolution data.

2) MQA have stated very emphatically that with regard to MQA being a DRM system the following:-
NO it ISN’T. We have no idea where this rumour came from, but we advise circumspection about the motives of those who persist in repeating this falsehood.

In fact, MQA is the antithesis of a DRM system: everyone can hear the music without a decoder!

Even FLAC requires a decoder, so does AAC, MP3, etc; vinyl and optical discs require players. There isn’t anyone who can’t play an MQA file on a mobile phone or an existing system.

DRM is about limiting access, tracking or copy protection. MQA does none of these.

MQA is about getting access to the definitive essence of great performances, with sound quality that is not otherwise achievable and reassuring you when you have it.

MQA files and decoders exist today, they can’t suddenly stop access to the music.

MQA does carry provenance, metadata and (optionally) creation rights information that might help the artist or publisher. It does not (unlike some downloads) carry information tracking the purchaser and we reject audible watermarks.
MQA does not have a DRM component."

As far as assertions of a walled garden, MQA also state explicitly "An MQA encapsulated file can be replayed without a decoder. This cannot be construed as a walled garden in any way."

I don't see how they can be more clear. We can only wait and see or call them liars which would be churlish and foolhardy in the extreme as no one as yet as been able to prove with one iota of evidence otherwise.

 

[RRod]

1) please excuse my ignorance and I would be very greatful if you or anyone else on the forum could enlighten me - what role do the random 0's and 1's below the noise floor contribute to the actual music that we hear? I had always been lead to believe that are merely random and well below the hearing threshold. If they have no discernible impact then I am not bothered about the area they occupy being temporarily used to store higher resolution data.

2) MQA have stated very emphatically that with regard to MQA being a DRM system the following:-
NO it ISN’T. We have no idea where this rumour came from, but we advise circumspection about the motives of those who persist in repeating this falsehood.

In fact, MQA is the antithesis of a DRM system: everyone can hear the music without a decoder!

Even FLAC requires a decoder, so does AAC, MP3, etc; vinyl and optical discs require players. There isn’t anyone who can’t play an MQA file on a mobile phone or an existing system.

DRM is about limiting access, tracking or copy protection. MQA does none of these.

MQA is about getting access to the definitive essence of great performances, with sound quality that is not otherwise achievable and reassuring you when you have it.

MQA files and decoders exist today, they can’t suddenly stop access to the music.

MQA does carry provenance, metadata and (optionally) creation rights information that might help the artist or publisher. It does not (unlike some downloads) carry information tracking the purchaser and we reject audible watermarks.
MQA does not have a DRM component."

As far as assertions of a walled garden, MQA also state explicitly "An MQA encapsulated file can be replayed without a decoder. This cannot be construed as a walled garden in any way."

I don't see how they can be more clear. We can only wait and see or call them liars which would be churlish and foolhardy in the extreme as no one as yet as been able to prove with one iota of evidence otherwise.

 
1) They don't. My point was that neither does any of the 8 lower bits of any 24-bit track I've ever heard at listening volumes.
 
2) I didn't mention DRM in my previous post; were you referring to the one before? Either way, proof will be in the pudding, so we shall see.
 
The "doesn't need a decoder" argument isn't compelling. Support for FLAC is pretty darn easy to get; it's like complaining about needing to get an unzip utility.

 

[Roly1650]

1) They don't. My point was that neither does any of the 8 lower bits of any 24-bit track I've ever heard at listening volumes.

2) I didn't mention DRM in my previous post; were you referring to the one before? Either way, proof will be in the pudding, so we shall see.

The "doesn't need a decoder" argument isn't compelling. Support for FLAC is pretty darn easy to get; it's like complaining about needing to get an unzip utility.

Not forgetting of course, that without a flac decoder you'd be wasting your time downloading all those MQA samples so thoughfully available from their technology partners 2L. Everyone a flac....

http://www.2l.no/hires/index.html.

There's disingenuous and then there's flat out confusing the issue.

 

[Gringo]

1) They don't. My point was that neither does any of the 8 lower bits of any 24-bit track I've ever heard at listening volumes.

2) I didn't mention DRM in my previous post; were you referring to the one before? Either way, proof will be in the pudding, so we shall see.

The "doesn't need a decoder" argument isn't compelling. Support for FLAC is pretty darn easy to get; it's like complaining about needing to get an unzip utility.

1) If this is so, then when some reviewers have claimed MQA is effectively lossless they are basically correct to all intent and purpose regarding listening to music

2) The proof is here and now. Anyone can go to the 2L website and download free MQA music files, (very limited and niche), and play them on your system, media player or smart phone at approximately cd quality with out any problems. The only caveat is that you don't get the full fat MQA treatment without a decoder that is MQA enabled.

 

[RRod]

1) If this is so, then when some reviewers have claimed MQA is effectively lossless they are basically correct to all intent and purpose regarding listening to music

2) The proof is here and now. Anyone can go to the 2L website and download free MQA music files, (very limited and niche), and play them on your system, media player or smart phone at approximately cd quality with out any problems. The only caveat is that you don't get the full fat MQA treatment without a decoder that is MQA enabled.

 
1) Well then the claim is really "audibly indistinguishable", but then they're basically aiming to be as good as higher-bitrate lossy codecs.
 
2) It's all about what starts happening after money is made, but of course they deserve the benefit of the doubt until something is actually detected and proven.

 

[Gringo]

1) Well then the claim is really "audibly indistinguishable", but then they're basically aiming to be as good as higher-bitrate lossy codecs.

2) It's all about what starts happening after money is made, but of course they deserve the benefit of the doubt until something is actually detected and proven.

1) "audibly indistinguishable" is a good way of putting it. I think they might well be aiming to be up with lossless codecs and if the truly are indistinguishable then lossless and lossy labels become totally irrelevant from the consumers point of view.

2) you can say that about most aspects of life. MQA or any other company can invent what they like, ultimately it will all be up to the record companies and download/streaming services. If they see money in it then it will happen if not it won't.

 

[Joe Bloggs]

The following graphic has been posted regarding MQA's audible effect on the noise floor of a sample 2L recording:


It would seem that the format introduces significant in-band noise whether it has been decoded or not.

 

[gregorio]

Originally Posted by Gringo /img/forum/go_quote.gif
 
[1] From what I have read it is not doing anything more than highres other than rectifying some artefacts that recording studio DAC's introduced in the past ...
 
[2] "audibly indistinguishable" is a good way of putting it. I think they might well be aiming to be up with lossless codecs and if the truly are indistinguishable then lossless and lossy labels become totally irrelevant from the consumers point of view.

 
1. Recording studios DAC's do not cause any artefacts, so there's nothing to rectify!
 
2. If they are aiming to be "audibly indistinguishable" from lossless codecs (highres, standard-res, flac, alac) then they are competing with high bitrate MP3s and AACs. Pretty much all consumer players already include support for AAC, MP3 or both. So why do we need another format which does not provide either any audible or functional improvement?
 
MQA, as you describe it, appears to be nothing more than an exercise in marketing, rather than anything useful as far as audio is actually concerned.
 
G

 

[lamode]

   
An article with this image in it:

 
isn't to be taken seriously. Streaming quality same as cassette? LP same quality as DVD-A? I must have taken my crazy pills this morning.

 
Yes, that chart is really off.
 
The problem isn't technology though, it's the consumer. We've had the technology to download lossless 16/44 files for over 20 years, but consumers chose the convenience of MP3 instead. The mainstream audio market just doesn't care about SQ.

 

[Gringo]

   
1. Recording studios DAC's do not cause any artefacts, so there's nothing to rectify!
 
2. If they are aiming to be "audibly indistinguishable" from lossless codecs (highres, standard-res, flac, alac) then they are competing with high bitrate MP3s and AACs. Pretty much all consumer players already include support for AAC, MP3 or both. So why do we need another format which does not provide either any audible or functional improvement?
 
MQA, as you describe it, appears to be nothing more than an exercise in marketing, rather than anything useful as far as audio is actually concerned.
 
G

 
1. Perceived wisdom generally accepts that each step of capturing, storing, manipulating and playing back music causes degradation and introduces artefacts, (this includes ADC's and DAC's, more so with legacy equipment). The general perceived wisdom is therefore less conversion, corrections and amplification results in more transparent, dynamic and realistic sound, (this has been used on forums to criticise MQA).

 
2. Addressing of issues of temporal blur and reducing of file sizes during downloading/streaming

 

[Gringo]

The following graphic has been posted regarding MQA's audible effect on the noise floor of a sample 2L recording:


It would seem that the format introduces significant in-band noise whether it has been decoded or not.

 
It would seem that the format does not introduce significant in-band noise whether it has been decoded or not
 
Extract from Computer Audiophile MQA Q&A article:-
 
 
PLEASE COMMENT ABOUT THESE INVESTIGATIONS/BLOGS


Q82. Please comment on these posts.
 
a.               http://archimago.blogspot.ca/2016/01...s-and-big.html (Blog post has been removed by author - Editor)
In this blog you will see, that from the technical point of view, MQA have around 13 Bit of “lossless” information and everything below 14 Bit is “lossy”. Doesn't mean that is will not sound good, it just means, that this is not a lossless codec, it is lossy (from the technical point of view).
b.     http://www.computeraudiophile.com/bl...ires-flac-674/

A82. We have paraphrased the assertions: ¹³

i) “MQA have around 13 Bit of “lossless” information and everything below 14 Bit is “lossy”

This is incorrect. In general, the MQA system can reach in excess of either 23-bit dynamic range capability or 3–6 bits below the content noise in the audio band.

ii) “Without a decoder we hear 13 bits, that isn’t CD quality”.

Here is a classic case of comparing apples to oranges. When we talk about CD quality sound we don’t expect an answer that says ‘it can’t sound like CD, because I can see only 13 bits’. Do we listen with our instruments? Even after years of working in this area we can’t look at an FFT plot and tell you how something will sound. We can maybe tell you the information capacity of the signal or the channel. One clue why it doesn’t help is in the second ‘F’ (for Fourier).

In any case the 13-bit number is wrong. Try as we might there is no way to tell the information capacity of a channel from a spectrogram (as in one of the cited posts) – the graphs look pretty but are basically meaningless.

As described earlier, if you don’t have a decoder, the channel capacity appears to be typically > 15 bits for the files on the 2L Testbench and this is limited by considerations of compatibility, not coding space. The noise is frequency shaped to minimise audibility, as it is for many well-produced CDs. If you have a decoder then, depending on the authoring parameters, the noisefloor in the recording should not be increased anywhere there is music signal.

iii) Paraphrase: ‘The Nielsen recording shows that MQA are cheating. They take a 16-bit recording and give us back a 24-bit file with lots of noise in it’.

Wrong. All one had to do was read Morten’s notes to guess it might have been remastered to 24 bits, See A40.


Nielsen: 2L-120 Track 1

As can be seen in the following, the inherent noisefloor of MQA in this recording is actually: 

Without Decoder: MQA channel noise is lowest around 4kHz @ 17.5 bits with a channel capacity of
15.8 bits which has been shaped. The MQA noise is always below that of the CD release.

With Decoder: MQA channel noise is lowest around 4kHz @ 24.3 bits with a channel capacity of
over 23 bits which has been shaped.

We have added to the graph (from our earlier note on the 2L website) to make this clear.


 
 

(High Resolution Image)



Note: the 24-bit Master and MQA (decoded) peak noise curves overlay and are not separately visible.

These graphs confirm that 2L’s Original, CD and MQA versions of the files are consistent in level and response. Of course spectral plots using FFT have no time-domain information, but we can use them to compare the peak spectrum of the Original, CD, and MQA with and without a decoder.
Also shown is a comparison of the background noise throughout each version and the reference level for 16-bit TPDF dither in a channel sampled at 44.1 kHz. ^14 15

In the graphs the peak and noise-floor curves overlay for both MQA decoded and Original master. We can also see that the shaped noise introduced by the MQA encoder and ‘heard’ without a decoder is removed by the decoder and is also below that of the CD release, even without decoding.

Additional curves explained:

With a Decoder: Brown (with open circles): This shows the underlying end-to-end MQA channel noisefloor (with a decoder) in this recording, which clearly shows that here the inherent noise of the MQA process is at least 10 bits (i.e. 60dB) below the noisefloor in the recording at all frequencies up to 22.05 kHz and close to 24 bits between 4kHz and 20 kHz.

Navy: shows the level of 24-bit TPDF dither for reference.

No Decoder: Magenta (with open stars): This shows the underlying MQA noisefloor for the listener with no decoder. It is lowest around 4 kHz and 12 kHz to minimise impact; is essentially below the 16-bit level up to 14 kHz and is always below the noise of the CD version. The inherent noise in the recording dominates below 15 kHz.¹⁶

Note: The noise seen by a Legacy (no-decoder) listener is the sparse signalling channel, not lossy noise in the file.


iv) Paraphrase: ‘MQA increases the noise in some recordings’ (an experiment using Explorer 2).

The underlying thesis in this blog has been to demonstrate that, because MQA uses burying techniques in the lossless folds, that somehow the dynamic range is restricted to 16 bits or fewer. We showed this to be incorrect regarding the Nielsen recording. We also disagree with the blog’s findings in the case of 2L ‘Blågutten’ from Quiet Winter Night. The graph below shows analysis of:


 

(High Resolution Image)

 
·         Files: Background noise levels in original DXD source and MQA file.¹⁷
·         Explorer2 analogue output when receiving: MQA (decoded in Explorer2) and the 192 kHz PCM version on the 2L testbench (background noise).¹⁸
·         References: showing 16- and 20-bit noisefloor @ 352 kHz (note, 9dB lower than at 44 kHz).
·         Analysis: The underlying MQA channel noisefloor in this file.
·         Hearing thresholds (steady-state) referenced to a playback acoustic gain of 105dB SPL.



The end-to-end core MQA noise floor in these encodings is always at least: 5 bits below the noise- floor of the recording up to 11 kHz, 4 bits below up to 22 kHz and is 3 bits below at 44.1 kHz (audio). However, no common DAC chip will reveal this due to internal noise. Even in these great 2L recordings we don't often see hall/microphone/ADC noise below the 16-bit noise spectral level -- not surprising given the fundamental thermal limit for microphones. See [2] and brown curve above.

In our experiment we don’t see the Explorer2 output deviate from the DXD or 192 kHz versions below 33 kHz. Above that there is rising dither from the DAC, but its origin is not lack of dynamic range.

The mastering engineer can set encoding or playback parameters where noise level can be increased or decreased in some frequency regions, but is not due to lack of dynamic range in the MQA system.

We should point out some key points for those less skilled in reading such plots:
 
I.                FFT analysis like this does not give any clear indication of how it is going to sound because temporal information is excluded.
 II.        The dynamic range is huge; the silence in the recording is 1/3 the way up the graph. For steady noise we hear nothing in the shaded areas.
III.        Even at high listening levels (e.g. acoustic gain of 112 dB), the noisefloor of the un-decoded MQA should be inaudible if the playback system is linear and has a flat response. With a decoder the noise is more than 20dB lower. [2][5][6][7][8]
IV.        Very few headphones or loudspeakers can reproduce above 40 kHz (shaded blue area).
  V.        Very few microphones pick up above 40 kHz, including in this recording.
VI.        Noisefloor above 44.1 or 48 kHz (especially at these levels) is more artefact than audio.[3]




¹³ There is an issue of bias: we take exception to blogs that block us from posting corrections!
¹⁴ The analysis uses 21.53Hz bins (=44100/2048 and 351800/16384) giving an offset of +13.33 dB wrt 1Hz. 
¹⁵ 2L sensibly use shaped quantisation for their CD releases.
¹⁶ Of course not all DACs can reach this low level of in-band noise.
¹⁷ Graph displayed up to 88.2 kHz for best comparison with blog.
¹⁸ The analogue output of Explorer2 was captured at 352.8 kHz/24bit in a Pyramix workstation using the Horus converter. The analogue noisefloor of the ADC is around 20 bits. Files were sent to the Explorer2 using Foobar.

 

[gregorio]

  1. Perceived wisdom generally accepts that each step of capturing, storing, manipulating and playing back music causes degradation and introduces artefacts, (this includes ADC's and DAC's, more so with legacy equipment).

 
It does not include DACs, legacy or otherwise! A studio DAC is there so that the engineers can hear what they are doing, what's in the digital files they are manipulating. The output of a studio DAC is routed to the studio speakers, it is NOT routed back into the actual digital audio files being manipulated. In other words, a studio's DAC is part of the studio's monitoring chain NOT part of it's recording, editing, mixing or mastering chain and it therefore cannot possibly introduce any artefacts!
 

  The general perceived wisdom is therefore less conversion, corrections and amplification results in more transparent, dynamic and realistic sound, (this has been used on forums to criticise MQA).

 
I have no idea who you are referring to when you say "general perceived wisdom"? It's certainly NOT the "perceived wisdom" of those who actually record and produce music/audio for a living! To start with, who even says that transparent, dynamic and realistic sound is in anyway desirable? Have you ever actually heard a  "transparent" rock band, IE. A rock band with no amplification or "corrections"? Without amplification, reduced dynamic range (and various other corrections), it's not even recognisable as a rock band! Secondly, a high quality commercial pop/rock (or any derivative genre) recording is likely to contain dozens of conversions and 100+ corrections. Obviously, the whole point of a correction is to correct something, to make it better, not worse! Lastly, less amplification would only result in more transparent, dynamic and realistic sound if there were too much amplification the first time round, otherwise it will result in LESS transparent, dynamic and realistic sound!!
 

  2. Addressing of issues of temporal blur and reducing of file sizes during downloading/streaming

 
This makes no sense. If "temporal blur" is an audible artefact which MQA addresses, then by definition it is not "audibly indistinguishable" from lossless or the best lossy codecs. If it is not an audible artefact then why address it (and why are you mentioning it)? You can't have it both ways! And, it's reducing file sizes relative to what, a 256vbr AAC?
 
G

 

[Gringo]

It does not include DACs, legacy or otherwise! A studio DAC is there so that the engineers can hear what they are doing, what's in the digital files they are manipulating. The output of a studio DAC is routed to the studio speakers, it is NOT routed back into the actual digital audio files being manipulated. In other words, a studio's DAC is part of the studio's monitoring chain NOT part of it's recording, editing, mixing or mastering chain and it therefore cannot possibly introduce any artefacts!


I have no idea who you are referring to when you say "general perceived wisdom"? It's certainly NOT the "perceived wisdom" of those who actually record and produce music/audio for a living! To start with, who even says that transparent, dynamic and realistic sound is in anyway desirable? Have you ever actually heard a  "transparent" rock band, IE. A rock band with no amplification or "corrections"? Without amplification, reduced dynamic range (and various other corrections), it's not even recognisable as a rock band! Secondly, a high quality commercial pop/rock (or any derivative genre) recording is likely to contain dozens of conversions and 100+ corrections. Obviously, the whole point of a correction is to correct something, to make it better, not worse! Lastly, less amplification would only result in more transparent, dynamic and realistic sound if there were too much amplification the first time round, otherwise it will result in LESS transparent, dynamic and realistic sound!!


This makes no sense. If "temporal blur" is an audible artefact which MQA addresses, then by definition it is not "audibly indistinguishable" from lossless or the best lossy codecs. If it is not an audible artefact then why address it (and why are you mentioning it)? You can't have it both ways! And, it's reducing file sizes relative to what, a 256vbr AAC?

G

I am sure you are aware that downloadable or streaming files can go through the process of conversion from analogue to digital and back again more than once before the final processed master file is created. Manipulation of the signals between these processes do impact the recording and can degrade the original audio capture. The fact that the fingerprint of legacy ADC's & DAC's is known and corrections can be made to account for them is an established principle. Obviously what was not captured can not be restored but added artefacts can be manipulated. This is my understanding though it seems yours might be quite different.

I used the "general perceived" comment to point out the contradictions that can be found in comments offered that on the one hand say that MQA only degrades and others which say MQA can not have an impact. As you stated, you can't have it both ways

As I understand it, ( and I don't pretend to understand all of it), Without the "white glove" treatment MQA is audibly indistinguishable but with it, sonic improvements are gained, (the degree/worthwhileness of improvement or otherwise I would not dream of speculating on).

When you question file size compared to what, you must know the answer to that if you have been following the thread. MQA reduces the file size of a hires file to that similar to a CD file for transference purposes and restores it to full bit perfect PCM on decoded playback

As you are clearly quite clued up on recording studio technology, if you can spare the time, (I am not being cynical), please read the computer audiophile Q&A article and tell me what answers are not correct, what factual inaccuracies can you identify. I would be very keen to know as I again, don't understand all of it.

It seems to me some contributors know a little/ know a lot about recordings and there transference and because they don't know all the facts, misinterpret/misunderstand MQA and are quick to dismiss it without ever having actually heard it. I repeat an earlier question I posed, have you or anyone else who has contributed to this topic actually heard a decoded MQA file and from what you have heard with your own ears actually concluded that is not comparable/ better or is of poorer quality? As ever we can all make as many tests, graphs, discuss technicalities as much as we like but they don't tell you what the music sounds like. I take it as read that the readers/contributers to this thread are concerned how good the music sounds to them above all else.