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Tidal’s New Lossless Tier Says Goodbye to MQA (but does it really?)

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sandymc

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Thanks. I took a look over that. Based on that and @Cebolla's description of the Tidal streaming, it appears that:

1. Green light: presence of an encrypted stream. I presume detected from the magic value plus checksums? So if the magic value isn't there, then MQA isn't detected or decoded?

2. Blue light, encrypted stream as above with auth_level greater than or equal to 9.

Is that correct?

I notice your description of "The position of this bit within the 24-bit samples is in the range 8-15 inclusive". How does that square with the belief that MQA only impacts on the lower three bits of a 16 bit stream?
 

sandymc

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mansr

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Thanks. I took a look over that. Based on that and @Cebolla's description of the Tidal streaming, it appears that:

1. Green light: presence of an encrypted stream. I presume detected from the magic value plus checksums? So if the magic value isn't there, then MQA isn't detected or decoded?

2. Blue light, encrypted stream as above with auth_level greater than or equal to 9.

Is that correct?
I believe so.

I notice your description of "The position of this bit within the 24-bit samples is in the range 8-15 inclusive". How does that square with the belief that MQA only impacts on the lower three bits of a 16 bit stream?
As I keep pointing out, that 3-bit idea is a misconception. That bitstream is _usually_ in the position that would be the LSB of 16-bit samples with another 8 bits of optional data below. In a few rare cases, it is at a higher position. The decoder looks for it in the 8 low bits of a 16-bit sample. Whatever position is used, dither noise is added, occupying ~2 bits above it. That means that there is typically approximately 13 bits worth of actual audio data above the MQA data and dither. However, this audio data is still not clean. It often contains aliased components from frequencies above 22.05/24 kHz. Since the decoder is able to (partially) put them back where they belong, I suspect some scheme similar to Dolby matrix coding is used.
 

sandymc

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As I keep pointing out, that 3-bit idea is a misconception. That bitstream is _usually_ in the position that would be the LSB of 16-bit samples with another 8 bits of optional data below. In a few rare cases, it is at a higher position. The decoder looks for it in the 8 low bits of a 16-bit sample. Whatever position is used, dither noise is added, occupying ~2 bits above it. That means that there is typically approximately 13 bits worth of actual audio data above the MQA data and dither. However, this audio data is still not clean. It often contains aliased components from frequencies above 22.05/24 kHz. Since the decoder is able to (partially) put them back where they belong, I suspect some scheme similar to Dolby matrix coding is used.

Ummm, that implies that, if you play an MQA file through a non-MQA Dac, so not even a first unfold, the only "unmolested" data you are certain to get is the top 8 bits?
 

mansr

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Ummm, that implies that, if you play an MQA file through a non-MQA Dac, so not even a first unfold, the only "unmolested" data you are certain to get is the top 8 bits?
Yes, but the worst I've seen in reality is the MQA stream being one bit above the LSB, so ~12 bits of (mostly) audio data. It's also possible for most of the PCM data to be encrypted, but I haven't seen any such files. They would be unplayable without a decoder.
 

sandymc

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Yes, but the worst I've seen in reality is the MQA stream being one bit above the LSB, so ~12 bits of (mostly) audio data. It's also possible for most of the PCM data to be encrypted, but I haven't seen any such files. They would be unplayable without a decoder.

Well, MQA is certainly a very clever encoding scheme. Very clever. A sort of twisted genius. But clearly poison to any non-MQA decoding chain, or a decoding chain with e.g., resampling or EQ in it.

It makes me wonder if the end-game is/was intended to be that users can either pay for an MQA certified signal chain end-to-end, or have to put up with mangled data.
 

Jimbob54

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Well, MQA is certainly a very clever encoding scheme. Very clever. A sort of twisted genius. But clearly poison to any non-MQA decoding chain, or a decoding chain with e.g., resampling or EQ in it.

It makes me wonder if the end-game is/was intended to be that users can either pay for an MQA certified signal chain end-to-end, or have to put up with mangled data.
Yup. Except they don't like you talking about mangling the data. It's lossless but it isn't, it's hifi but it isn't. It's perceptually lossless etc etc
 

dmac6419

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Australian users have already reported that many of the "CDs" are so called MQA-CD's. I don't know why you would expect anything else, as Tidal has already eliminated thousands of Redbook CDs from the catalog and replaced them with MQA-CD versions. Apparently they are stripping the MQA tags from the files so as not to trip a decoder.
That is actually the worst of all worlds: less than actual Redbook quality and the bastardized MQA versions of the files.
Switch to Qobuz,problem solved.
 

tmtomh

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I can believe it, storage is cheap, they are already storing the lossy ones in multiple bit rates, and having the files already there reduces processing, and simplifies the code. I've read previously that for streaming services storage is cheaper than processing, but I expect 'it's complicated' is the true answer.
Their implementation today might not match their implementation in 6 months, what they have done right now is almost development free, so it could just be a quick reaction to the market, or maybe they really don't care.

You make a good point about storage. However, on the other side of the equation, there's the fact that MQA's model/aspiration from the outset has been "many playback scenarios, one file." While this was marketed as a storage/bandwidth/device capacity flexibility idea rather than a subscription-tier idea, it nevertheless remains the case that serving up the same MQA files in undecoded and decoded options is precisely what MQA envisioned from the outset - it's a use case that falls exactly in their model, and so in my view it is not surprising that Tidal is just re-using unflagged/undecoded MQA for the standard Hi-Fi tier and I would not expect them to change that.
 

tmtomh

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Of course it is. They were quite open about this in the early (Pono) days, and you can still read it between the lines.

Yes, exactly - and while I am glad to see what appears to have been steadily growing opposition to MQA, I can't quite get why so many technically savvy folks still don't seem to see this, or to see it as a problem in the marketplace of digital music content.
 
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AdamG247

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Yes, exactly - and while I am glad to see what appears to have been steadily growing opposition to MQA, I can't quite get why so many technically savvy folks still don't seem to see this, or to see it as a problem in the marketplace of digital music content.
They have created a very large and effective Circle of Confusion.
 

mSpot

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what they have done right now is almost development free, so it could just be a quick reaction to the market, or maybe they really don't care.
I agree, it is simply a quick and easy way to introduce a lower priced middle tier with minimal effort, for marketing purposes. Some people want to analyze it from the technical side and it just demonstrates the crazy obsessiveness of audiophiles.
 

RosalieTheDog

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Australia-only so far...check out the AUD prices:

"Note that the pricing below is for Australia ONLY. Please click here to see plan availability and pricing in your region.
  • Premium - $11.99 AUD a month with standard sound quality (320 Kbps)
  • HiFi - $17.99 AUD a month with lossless High Fidelity sound quality (1411 Kbps)
  • HiFi Plus - $23.99 AUD a month with lossless High Fidelity sound quality (1411 Kbps), Master Quality audio (up to 9216 Kbps), and immersive audio - 360 Reality Audio, Dolby Atmos Music
  • Family Premium - $17.99 AUD a month including up to 5 additional family members totaling 6 on the account. Standard sound quality (320 Kbps)
Would this mean family hifi is gone?
 

RosalieTheDog

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Switch to Qobuz,problem solved.
I would, particularly since the similarly priced family subscription has become available. But its app so frequently freezes on Windows and behaves erratically on Android, far less stable than Tidal imho.
 

dmac6419

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I'd bet Bob has taken a beating internally every time he has to justify a lie. But he may not have any morals left and only cares about the money. Hell, his credibility is shot with thousands online.
No with me.
 

hmscott

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Would this mean family hifi is gone?
According to Tidal's own Australia Pricing Plan page, yes, there is only the "Premium Family" remaining... perhaps that is a mistake and Tidal will correct that soon, or before the changes come to the US.

Perhaps email Tidal Support and let them know you saw this coming and aren't happy about it.

(Austrailian Tidal) Subscription Types – TIDAL
https://support.tidal.com/hc/en-au/articles/115003662825-Subscription-Types
 
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