MQA: A Review of controversies, concerns, and cautions

[dmac6419]

Any prove this is happening?

The label will send Spotify the master files,Spotify then have to downsample the file to fit their format,etc,so if the label only sent HDTRACKS 16/44 HDTRACKS would upsample to a higher bitrate and they were called out on it.in other word when the label send files they can do what they want with the files

 

[R1200CL]

This is exactly what I'm saying - look right below the second red circle you've drawn: MQA core decoder, 24 bit, 88.2kHz. That's the native sample rate of the file. 3/4 of the samples in the original 352.8k source have been thrown out and the 352.8k final output is a result of upsampling of the resulting 88.2k actual file it just copies each sample 3 times to return the sample rate to 352.8k - but 3/4 of the original samples are gone forever. That's the scam.

You have it all wrong, and don’t understand how this works. The original encoded file from recording company is 352,8. The first unfolding is 88.2. The rest of unfolding must take place in a DAC. The MQA decoder does no up or downsampling at all. It decoding the ogami. If an ogami exist. MQA exist also without ogami. Any encoded file displayed as MQA 44.1 or 48kHz has no ogami. Roon and probably other decoders will by an error claim it has.

The transfer rate in this case is FlAC 44.1 and bit depth is 24.

 

[Rock Rabbit]

it can ensure that the file you received came directly from the publisher / producer without any tampering. WITHOUT copy protection.

Without any tampering? Like a lossy perceptual CODEC manipulation and time resolution manipulation of any microphone and console (without any transparency of the process) and with encrypted hi res content with a secret obscure proprietary algorithm (70s style! encryption)...

 

[abdo123]

The transfer rate in this case is FlAC 44.1 and bit depth is 24.

this is a ballsy claim, any proof?

It would invalidate a lot of anti-MQA arguments.

 

[R1200CL]

I think there was an incident where HDtracks (not a particular publisher) has been selling upsampled tracks but i'm not sure.

This is correct. But is was not done by the recording company. That’s was my point and what I wanted a prove.

 

[Blumlein 88]

No you're incorrect, according to their website the tracks are encoded by the producers of the tracks themselves, that's what 'Master Authenticated Quality' represents, it's authenticated by the masters of the track. so it's not misrepresenting anything when the producers OKed it.

Another lie.

 

[R1200CL]

this is a ballsy claim, any proof?

Explain to me how you understand information given here. There should only be one possibility explanation.

It would invalidate a lot of anti-MQA arguments.

Not at all. Maybe you can explain better with one example.
Of cause even a mp3 file can be transported in a container 44.1/24bit. I’m not debating what the container contains.

 

[KeenObserver]

This is correct. But is was not done by the recording company. That’s was my point and what I wanted a prove.

I was going to respond to a post but I'm tired. Going to listen to some music and go to bed. I have to give you credit for your perseverance in searching for the truth. What is it like 4 AM there in Norway?

 

[abdo123]

Explain to me how you understand information given here. There should only be one possibility explanation.
View attachment 98858


Not at all. Maybe explain better with one example.
Of cause even a mp3 file can be transported in a container 44.1/24bit. I’m not debating what the container contains.

I'm talking about the origami-less MQA (MQA 44.1 or 48).

are the 16 bits completely unaffected? and the extra 8 bit has the authentication data ?

 

[KeenObserver]

Interesting! Does attacking HDtracks make MQA seem more honest?

 

[abdo123]

Interesting! Does attacking HDtracks make MQA seem more honest?

At least MQA scams are out in the open hahahahah.

 

[Emlin]

MQA lie. I have many other reasons to dislike them and what they do, but that's the only one that I really need.

 

[R1200CL]

I'm talking about the origami-less MQA (MQA 44.1 or 48).

Maybe we’re talking past each other. Are you talking about MQA encoded files displayed as MQA 44.1 or 48 ? Yes, they can’t unfold if that was what you is discuss with me.

are the 16 bits completely unaffected? and the extra 8 bit has the authentication data ?

I don’t get you. There exist either encoded 16 bit or 24 bit in various sample rates.

You may take some time to read Bob talks. He is hard to understand, so he is contributing to confusion.

To be clear, I‘m not discussing the actual true bitrate and how it’s done. 13, 15 or 17, or whatever. There is a lot of information out there.

 

[Blumlein 88]

I'm talking about the origami-less MQA (MQA 44.1 or 48).

are the 16 bits completely unaffected? and the extra 8 bit has the authentication data ?

If I remember rightly, the 44/16 MQA undecoded gives 13 bits back and the extra info is in the lower bits.

In the 24 bit versions I think you get 17 bits and they use the lower 7 bits for the other info. Mansr is the guy to ask about this.

 

[tmtomh]

You have it all wrong, and don’t understand how this works. The original encoded file from recording company is 352,8. The first unfolding is 88.2. The rest of unfolding must take place in a DAC. The MQA decoder does no up or downsampling at all. It decoding the ogami. If an ogami exist. MQA exist also without ogami. Any encoded file displayed as MQA 44.1 or 48kHz has no ogami. Roon and probably other decoders will by an error claim it has.

The transfer rate in this case is FlAC 44.1 and bit depth is 24.

No, I'm sorry but you are the one who has it all wrong. A 352.8k original is downsampled to 88.2k, which is then folded into a 44.1k container file. Undecoded, the MQA file will play back at 44.1k. Unfolded ("core") it will play back as 88.2k. Fully rendered - "the rest of the unfolding in the DAC" as you say - it will play back with the DAC and/or playback software showing 352.8k - but that is because the "rest of the unfolding" is what MQA calls the final render, where in Bob Stuart's sly words they "put the sample rate back to what it was." The 352.8k sample rate is generated - not decoded or restored - via a quadrupling of the native 88.2k sample rate of the MQA file - it's not the actual original samples from the original 325.8k PCM file that the record company file started out with.

So once again, here is the chain:

1. Record company 352.8k PCM original (assuming in this example that they have an original at that resolution)
2. Record company runs that original through MQA encoder
3. MQA encoder downsamples 352.8k to 88.2k - throws out 3/4 of the samples (I know you think this can't be true, but it is)
4. MQA encoder then "folds" the the 88.2k into a 44.1k MQA container, via lossy compression of half the samples, encoding that lossy-compressed data in the lower bits of the files
5. MQA "first unfold"/software decode on the playback end decodes the 44.1k container file back into 88.2k
6. Hardware DAC "final render" upsamples the 88.2k to 352.8k and applies allegedly "custom" MQA reconstruction filter

Crucially - and the bit you don't get - Step #6 does not "unfold" 352.8k sample rate information that is encoded in the MQA file - all that's encoded in the MQA file is 88.2k. The additional samples of the original 352.8k PCM file the record company started with are gone forever, and the MQA final render simply makes 3 additional copies of each sample, thereby quadrupling the number of samples, in order to bring the file back up to 352.8k.

Now, it is not surprising that there is confusion about this - MQA has been misleading in their communication about it from the beginning. By calling it "audio origami" and referring to a "first unfold," they have strongly implied that there are multiple "folds" and that the full 352.8k sample rate info can somehow be folded up/encoded into a file that ends up as a 44.1k container. That's impossible and is not what happens.

Personally I don't care if the file is 88.2k, 176.4k, or 352.8k - there's no sonic difference. But MQA is marketing them as 176.4k and 352.8k and Bob Stuart is claiming (incorrectly) that "new neuroscience research" shows that the ultrasonic information from those higher sample rates is meaningful. So he and MQA are being deeply misleading, allowing the impression to circulate that something beyond 88.2k/96k is contained in an MQA file when it most certainly is not.

If you take a 352.8k PCM file and downsample it to 96k yourself in Audacity or any other audio editor, and then run that 96k file through the MQA encoder, when you play it back on an MQA-capable system and DAC, it will register as 96k. If you take the same file and do not downsample it to 96k yourself and run it through the MQA encoder, the MQA encoder will downsample it to 96k before doing any other processing. But because the file you gave the MQA encoder was 352.8k, when you play back that file on an MQA-capable system and DAC, it will register as 352.8k. In both cases the file has been downsampled to 96k - it's the same file. But in one case the MQA DAC will show it as 96k while in the other it will upsample it and show it as 352.8k.

 

[Blumlein 88]

To add to what tmtoth is saying. 0-20 khz material is the full bits, 20-40 khz material is a lossy encoding which is hidden in those lower bits. If you go above that then it is upsampled and using the shallow filters there is aliasing and imaging which will put something up there perhaps sort of related to the signal, but it isn't actually like you are getting playback of anything recorded above 40 khz bandwidth. It is nothing like the promised idea of getting playback from that small file that matches 352 khz sampling rates. That is before we begin to beg the question of what is up there in that high ultrasonic region in the first place.

 

[Tks]

Now, it is not surprising that there is confusion about this - MQA has been misleading in their communication about it from the beginning. And personally I don't care if the file is 88.2k, 176.4k, or 352.8k - there's no sonic difference. But MQA is marketing them as 176.4k and 352.8k and Bob Stuart is claiming (incorrectly) that "new neuroscience research" shows that the ultrasonic information from those higher sample rates is meaningful. So he and MQA are being deeply misleading, allowing the impression to circulate that something beyond 88.2k/96k is contained in an MQA file when it most certainly is not.

If you take a 352.8k PCM file and downsample it to 96k yourself in Audacity or any other audio editor, and then run that 96k file through the MQA encoder, when you play it back on an MQA-capable system and DAC, it will register as 96k. If you take the same file and do not downsample it to 96k yourself and run it through the MQA encoder, the MQA encoder will downsample it to 96k before doing any other processing. But because the file you gave the MQA encoder was 352.8k, when you play back that file on an MQA-capable system and DAC, it will register as 352.8k. In both cases the file has been downsampled to 96k - it's the same file. But in one case the MQA DAC will show it as 96k while in the other it will upsample it and show it as 352.8k.

Wait, what the hell? Why on earth would he claim this? MQA (whatever the hell it does at any point) I've seen NO EVIDENCE AT ALL they're based on any perceptual encoded psychoaccoustic models.

Has he ever substantiated this claim without invoking idiotic effects on brain signals or something? What is he talking about when he says "meaningful"? Or is he still hoping for benefit of the doubt after half a decade of folks waiting on him to substantiate his claims?

 

[majingotan]

I'm talking about the origami-less MQA (MQA 44.1 or 48).

are the 16 bits completely unaffected? and the extra 8 bit has the authentication data ?

The extra bits is just there to decode it to 24 bits through the core MQA decoder (no software MQA rendering involved), and if software rendering is involved per Tidal, there will ALWAYS be a 1st unfold that occurs. The lossless FLAC versions from Qobuz is essentially the same master and same bit and sample rate as Tidal MQA when fully decoded (24/48 or 24/44.1) since the studio did not release the 24/192 original master file to the public

 

[levimax]

Wait, what the hell? Why on earth would he claim this? MQA (whatever the hell it does at any point) I've seen NO EVIDENCE AT ALL they're based on any perceptual encoded psychoaccoustic models.

Has he ever substantiated this claim without invoking idiotic effects on brain signals or something? What is he talking about when he says "meaningful"? Or is he still hoping for benefit of the doubt after half a decade of folks waiting on him to substantiate his claims?

They make a lot of crazy claims including knowing what dead people heard in the recording studio 50 years ago. The problem is many non technical audio enthusiasts have a strong desire to believe in magic and latch onto anything that they hope will add magic to their system and will overlook details like lies and DRM like schemes and of course spending more money.

 

[JustAnandaDourEyedDude]

So explain this then? And it can even be double. But transfer rate is max 44.1 or 48kHz. (16 or 24 bit). Or did I misunderstand your point.
View attachment 98837

Have you been interpreting such a display to mean that the transmitted 2x44.1/24 FLAC is magically a lossless compression of every putative 352.8kHz original master of mystery provenance, which is magically unfolded back to the 352.8kHz Studio master by the MQA renderer? I have news for you. Please look up the mathematically proven "no free lunch" theorem in data compression, as well as the pigeonhole principle. No data compression algorithm can losslessly reduce the size of every possible 352.8kHz bitrate file to 2x44.1/24 bitrate. If such an algorithm existed, one could apply it recursively to losslessly reduce file size and bitrate down to zero. Even taking advantage of the special attributes of audio data, there are hard limits to how much the file size can be reduced losslessly. Please look up "information entropy" and "Kolmogorov complexity" and "incompressible strings".