MQA bit rate analysis and 1st unfold question

It is my understanding that the Meridan Unplugged spreadsheet is the definitive list of TIDAL MQA releases (http://www.meridianunplugged.com/downloads/MQA_List.csv)

If not, please correct me but if it isnt it still paints some interesting questions (for me at least)

I did some analysis of this SS (albums only, not EP’s/singles) and was surprised by the original MQA bit rate breakdown:

image

25% of the MQA albums on Tidal are 44k and 32% are less 48k or less…aka not really hi-rez

Also while there are 9119 albums, only 7872 are unique (relative to album/artist) …aka 14% are duplicates in some way.

And despite the hype and the suggested tsunami of MQA titles on TIDAL, ~9000 albums in 4 years isnt much.

So I have questions now that ROON does the first unfold.

Web research says that the maximum first unfold rate is 24/96… so given the vast majority of the TIDAL MQA albums are 96k or less…one has to assume that the first unfold for the albums that are say 96K wont hit my DAC as 24/96? (my DAC cant do the 2nd unfold).

And what of the 25% that are 44k… what will my DAC see?

Or will any MQA album that is 24/96 or less hit my DAC at the stated MQA rate?

Thanks,

Peter

Hi Peter, if it’s an MQA 96k file and Roon is doing the 1st unfold then your DAC will see 96kHz (if the path to your DAC input is bit perfect).

I used Spec analyzer and Audio Hijack on Mac to look at output of the Roon first unfold of the MAGNIFICAT album (Tidal MQA 353kHz) and compared with the 96kHz file I purchased (same DXD master - this is the most critical thing, ensuring the same master for comparison).

The output of the 1st unfold looks identical to the 24/96 available for purchase. And this is for an album with significantly more dynamic range than I normally listen to.

It’s quite easy for anyone to check - again emphasis on comparing same master.

This is just looking at the 1st unfold and nothing past that - as I don’t have an MQA DAC either.

From Archimago:

"Objectively with the songs I examined, the software decoder works well to reconstruct what looks like the equivalent 24/96 download."

and

"Bottom line: TIDAL/MQA streaming does sound like the equivalent 24/96 downloads based on what I have heard and the test results"

Hi Peter,

The MQA decoder always outputs a MQA renderable stream at 88KHz / 24 bits. or 96KHz / 24 bits.

If the original sample rate is less than 88KHz the decoder will upsample it.

EDIT
@peter_oshea,
Sorry my reply was over simplified, now edited to allow for both 88KHz and 96KHz output.

thanks to both for your replies.

It very interesting to think that the rate from the 1st unfold is always 96K.

Means for example that 44.1 (which comprises 25% of the MQA TIDAL library) will undergo async/non-integer upsampling inside ROON.

One of the main reasons I got my Bryston BDA-2 DAC was that its upsampling is always synchronous no matter what the “root” rate is (44.1 or 48).

It will be interesting to see what the CPU utilization on my lowish powered slient PC is when ROON does say an upsample from 44.1k

Again thanks for the replies.

Peter

Most off selves DAC chips will do internal up-sampling to 352.8k or 384k depending whether it is 44.1k or 48k multiples. On top of this, they will apply standard filters; mostly sharp cut with a lot pre and post ringing. This has been done since 8x over-sampling CD players came out.

So irregardless whether the input source is 44.1/48k, 88.2/96k or 176.4/192k, all will be up-sampled to 352.8/384k internally inside the DAC. The end result is always the same; the DAC is always converting at 352.8/384k stream.

Here is a clear and deep interview with Bob Stuart on MQA by J H Darko

Two short videos…

Actually the MQA decoder will output an 88.2k stream where the original sample rate was 44.1k. Carl’s reference to 96k is the maximum and occurs when the original sample rate was 48k. You can see this on the Roon Signal Path when the MQA decoder is operating.

Brian has corrected me on the (repeated) occasions when I have referred to 44.1/48 original sampling rate material being “upsampled” to the MQA decoder output of 88.2/96k. Mainly I think to distinguish the MQA decoding from upsampling in the Roon DSP Engine (which is not used by the MQA decoder) but also faintly mysteriously as to other claimed audio benefits by MQA. I persist in thinking of it as upsampling.

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First unfold of MQA 44.1kHz will be 88.2kHz.
First unfold of MQA 48kHz will be 96kHz.

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The first decoding can behave like 1st unfold or up-sampling depending on the OSR of the recording album/track.

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I guessed he is implied that all DACs even the same models and the same batch will sound different. So one has to send them to MQA, do some ‘certification’ works then all will sound almost the same? Another way to make more $$$? I felt his argument is BS.

I have listened to both sides of the argument and plenty of MQA encoded/decoded music and I know where I place my trust.
If you have watched both videos and yo’ur still not understanding, then that’s just how it is. As Bob says in his opening remark, “it’s all my fault” lol. I like that.
We agree to differ, we will always have a choice, all we have to do is make it.

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@Chrislayeruk
The whole problem about MQA was they made so many ‘claims’ in the past that it takes people like Archimago’s Musings, Computer Audiophile and hardware manufacturers like Schiit to come forward that those ‘claims’ are not justifiable. Well respected PS Audio audio guru like Paul McGowan cast his own doubts too. The recent AES listening test have shown there’s no significant difference between PCM and MQA, which MQA claimed it sounds better than the original master copies.

I think people have heard enough of all these BS. I guessed it takes a while to fade away, been 4 years now? Just give it more time…

I just seems like you don’t get it at all, which is OK. But MQA is about the output being analogous of the input and not about all the digital in between. Nothing analog is lost…

This is a new paradigm

MusicFidelity has a pretty good grasp when it comes to MQA and definitely gets it.

New paradigm and cash grab by Bob are definitely analogous. Analog input and output not so much, it’s just flavouring and ultimately advantageous to the studios, nothing more.

Well, there is nothing more to say then…