Tidal and MQA (oh no, not again)

Streaming Audio
41

I’m with @simon.pepper on this, and it’s been my understanding since reading the original description of MQAlong before it was offered on Tidal, long long long before Tidal started prioritizing its MQA versions over the standard Red Book ones.

I think there has been confusion over the use of “Hi Res”: some people (and almost all here) use it to mean “higher than CD” 44.1/16, but others (mainly coming from the “default lossy” world) use it to mean “better than whatever lo res MP3 you’ve been listening to up until now” (and it often tops out at Red Book). Lots of op ed articles on this out there, as it’s definitely a political stance…

In the case of MQA version of a CD quality source, the as-delivered 44.1/16 stream played back directly (ie no “unfolding” at allis indeed not a bit perfect version of the original Red Book file. Call that lossy, noisy, adulterated… whatever you like: it’s the same bit rate / but depth of course (so in that sense you might argue that “lossy” is an inappropriate word to describe what’s happening), but it is not the same signal. This is likely “bad” and audible…

But after the first unfold (eg software via Roon, or any other way you like), then the container (at 44.1/16) has been unpacked into a higher bit rate / bit depth stream for your DAC to convert.

As I read the claims, the compression algorithm from MQA fully covers the 44.1/16 space in the first-fold “triangle” (see the diagrams explaining the “origami” approach), and only partially covers the higher resolution (eg 96/24) space. The second “unfold” offers better, but still not complete, coverage of this 96/24 information space… hence even after both unfolds, MQA is a lossy compression / decompression encoding technique for original signals that are “higher res” than Red Book. But, whether after only one or after all of the unfolding has been done, the resulting higher bit rate / bit depth stream contains the full Red Book signsl (plus some noisy least significant bits that are below the Red Book noise floor and thus are irrelevant to the signal information content).

So in that sense, I’ve always felt that the confusion over “lossless” and “lossy” and “Red Book” and “Hi Res” has been massive and complicated and is at the heart of the (technical, but not the DRM) arguments for and against MQA.

TL;DR: for a CD source file, unfolded MQA is lossy but even a first-unfold-only stream has all the Red Book content; no amount of unfolding gets back a bit perfect data stream of a 96/24 source file, these are (tuned) lossy encodings for higher-than-CD res recordings.

As for Tidal replacing CD recordings with MQA, it is certainly tricky and a bit obscure…. Tidal definitely “push” the MQA versions now, but their website confirms both MQA and Red Book formats are offered. So if you search on an MQA title using the Tidal app, eg via that artist, then select “other albums” or “discography” you can still find the non-MQA version buried in there; favourite whichever ones you like, both are there. In the older Naim interaction with Tidal, I recall seeing both versions on display…. I don’t see that as often now. But @Stevesky has explained that the Naim stream pulls the non-MQA Red Book version for us since that’s how the hardware works best. In Roon, it is possible to see “versions” and choose the one you want, plus control whether the first (software) unfold takes place or not. Your choice, your call.

Possibly I’m horribly wrong… but I really don’t think so! Happy to hear from others with a different take on this!!

Regards alan

2 Likes
42

I see, Agreed

43

Your understanding concurs with mine.

As for the term ‘hi res’, you may be right that some people think of lossless 16/44 as hi res because they are accustomed to lossy mp3 type compression, however in the hifi world convention has it that it means anything with higher resolution than standard CD.

44

Yes, but you are assuming I am listening to stations & content broadcast and able to be received in the location I reside.

45

Hi Alan,

…Almost. A couple of points:

First you are conflating resolution and algorithmic data loss: Although in ‘common parlance’ “resolution” is often used to signify information loss, it’s not actually correct. MP3 can be (and often is) full 16/44.1 resolution, but the algorithm throws away some of that data and then compresses the rest. On decompression the resulting file still has 16 bits of valid data and is still clocked at 44.1kHz, so the resolution is unaffected; however those data are not the same and the original file, the difference is the lost information. (N.B. lost information not lost data!).

Secondly, and this may well simply be just slightly woolly wording: The way tidal selects the data stream for a non MQA streamer is that when the streamer requests the data stream (probably via an ID tag from the Tidal catalogue to identify the stream to play) it also sends information about it’s rendering capabilities. Tidal then uses this information to decide what data stream (including MQA or not, it will send to the streamer in response. Tidal then acknowledges the request. The streamer then starts asking for data blocks, pauses when it’s buffer is full and requests more data blocks as the buffer empties. The upshot of this is that ALL the logic that decided whether the data stream is MQA or FLAC is entirely in Tidal’s domain, whereas the flow logic is in the renderer’s domain.

In short (TL;DR:)
The renderer requests the subject matter of the data stream, Tidal then decides what data to make available to the renderer, and the renderer ‘pulls’ the data (rather than Tidal pushing the data).
So Tidal could very easily connect a non-MQA enabled renderer to an MQA encoded 16/44.1kHz datastream and the data would still play, albeit with a compromised 13bit resolution.

46

But why? I’m happy with my own filing system without Roon. If the purpose is to get MQA, I’m not particularly interested in that.

And I still read posts that Roon struggles with classical recordings. Why would I want it to mess around wit my own library in any way?

47

Easy answer: if your current setup gives you everything you need and want, you don’t have a reason to use Roon

48

Can you help me find “other albums” or “discography”? A screen shot would be fantastic. For the record, I tried finding them in the Windows 10 app. Happy to find it on the iOS app as an alternative. And what happens if I’m not looking for an album? I have a workout playlist that I access most often through LMS as I prefer the interface. How can I tell what Tidal is sending me?

49

Yes I can try, but I’m not expert on this either… and I may have used imprecise terms! Here’s an example, using the iOS Tidal app, for the new Solar Power album by Lorde. I hope other stuff works this way also, but have not really checked tbh.

  1. Search “Lorde” and choose “artist” (top hit)

  2. scroll down to “albums” results (the Master is shown first); choose “view all” (here you can see both MQA and regular version of Pure Heroine, but only MQA for Solar Power)

  3. choose the Master of Solar Power; scroll all the way down past the track listing and you find “More albums by Lorde”… and here you get (two? copies of) the non-Master version of Solar Power.

I’m trusting that Tidal uses the “Master” icon to flag the MQA version, and that the one(s) without that identification are the Red Book version.

Hope that helps a bit… I did this by poking around and, tbh, it’s different looking now than it was before. Good luck, especially with your playlists and other apps (sorry, can’t help with that I don’t think).

Regards alan

ps - if you search “Lorde Solar”, and choose the “albums” tab, rather than the “top” tab, you get all three versions at once: one labeled “Master” the other two not… a few steps shorter, and an alternative way to seek the format of your choice.

50

Roon won’t ‘mess around with your library’, it will just offer you an alternative view of it which you are not obliged to use. It can do a lot more than just manage metadata. Only you can decide if any of the facilities it offers appeal to you. Thus the free trial option.

2 Likes
51

Worked for Lorde, but not for Fleetwood Mac Rumours. :man_shrugging:

52

Triggered by the MQA / 13 bit discussion, I’ve been going back & forth between Tidal and Qobus the last two days. I have a hard time hearing a consistent difference between the two. If there is, it’s marginal and swings both ways. Maybe it’s my music, system or my ears though… :relaxed:

53

Upon reflection, I think I’m going to hang tight and see what Spotify has to offer. As I mentioned, my Google Home/Nest/ChromeCast devices will stream Spotify natively, even allowing for voice control.

1 Like
54

Ahh I was wondering WTH was going on.
Hope Innuos come good with a Roon like first unfold.

55

I find Qobuz usually a little better when they have a 24 bit version. If it’s regular 16/44.1 I found no difference, but that small advantage, along will the full lossless hires material instead of MQA, tipped the balance in favour of Qobuz for me.

1 Like
56

Or you can use the managed list of all MQA available here as a CSV file.
https://www.meridian-audio.info/MQA/MQA_List.csv

From here, you can sort by date added, search by Artist etc, and obtain the Tidal URL

57

Cool! Now, if there is an equivalent method to get the location of the non-Master version of the same title, everyone’s happy! Do you know if that’s possible?!?

Regards alan

58

There’s also the question of what you are actually getting from Tidal…
13bit MQA or 16bit FLAC.

59

It’s entirely possible that the MQA and FLAC versions could have the same external identifier, i.e. have the same URI, being distinguished for playback by an ID that’s only visible internally within Tidal, restricted to Tidal’s internal database and server processes.

60

My original question, although it seems to me evidence is accumulating that you get the 16bit FLAC. I noticed that when you buy an album from Tidal (generally at an exorbitant price, so I have never done so*) your choices are always mp3 or FLAC. Never MQA (AFAIK). So even though the only visible version of Rumours on the streaming site is a MASTER, they have the FLAC to sell.

  • I do keep looking at the Miles Davis Complete Plugged Nickel download.