Article: MQA (for civilians)

[DanSmedra]

It seems one of the major current tensions among audiophiles in various forums is the viability and supply of music delivery channels. Hi-res music owners clearly seem threatened and angst over streaming music becoming too popular and its SQ too good. I think their concerns are unfounded.

 

As silly as it sounds, some forums have small groups of anti-streaming and MQA 'protestors'. I'm not sure whether they are retired, unemployed, or live in mom's basement, but they are drawn (as if with a sci-fi tractor beam) to express dissent and write denigrating comments toward that segment who enjoy streaming and who optimistically look at MQA as a possible enhancement to sound quality and musical enjoyment.

 

Enthusiasm for TIDAL/Masters and the emerging market for MQA-certified hardware seems to make certain audiophiles downright miserable...as if music pleasure is a zero-sum equation. "It's just not 'fair'!" Really?

 

Audio Industry Take Note. Those of us who enjoy streaming services like TIDAL, Pandora, Spotify, etc. and its ability to introduce music listeners to new artists and genre as well as replay favorites from massive cloud-based libraries, are excited about TIDAL/Masters and the future of MQA.

[perolator]

I listened to MQA at Meridian in NYC in March 2015. The MQA files in the demo sounded way better than the "standard" files. The people giving the demos were either completely ignorant or deceptive as they would not answer any of my questions. And I do not believe the MQA versions came from the same master. So really very deceitful if you ask me, frankly.

 

But... Do I like the sound of many of the MQA albums on TIDAL? Yes. Are they better than even my so-called hi res versions of these albums? Almost across the board the answer is: Yes. Is it because of MQA, deblurring, origami, or some of Bob Stuart's hair interspersed in the file? I don't know and I frankly don't quite care. Call me a cynical pragmatist.

 

I like a lot MQA on TIDAL. I think the psychoacoustical analysis of the files in the MQA process helps a lot. Snake oil? I don't know. MQA sounds incredible. I'm scratching the origami folding thing (no more unfolding than TIDAL's own) but the sound quality is noticeable.

[ednaz]

Very good explanation. Now I understand why I heard the differences I did with software decoding, through different DACs, and hardware decoding through the Explorer 2. My best DAC (not MQA) with software decoding in front mopped the floor with the Explorer 2 in full MQA hardware mode - because the differences between the DACs themselves were way more than the hardware decoding uplift. After fiddling with multiple DACs and different ways of playing back (and now I understand what went on behind what I heard) I'm a huge fan of MQA for streaming Tidal, but I'm unlikely to re-buy any music with MQA encoding. I did comparisons between streaming some of Tidal's MQA and HD non-MQA versions of the same music stored on my server, and local won (except on music recordings where everything was turned up to 11 in the production process - where the two were dead equal.)

 

And while I wouldn't object to buying a DAC with MQA decoding capability, that would only be if the DAC is the best I can get at the price point for non-MQA playback... meaning, the MQA decoding pretty much needs to be a free feature. For the Explorer 2, in fact, that's kind of how it seems to me. It's excellent at its price point, with MQA thrown in.

[Bryan]

Hi-res music owners clearly seem threatened and angst over streaming music becoming too popular and its SQ too good. I think their concerns are unfounded.

 

Not this Hi-res music enthusiast. Over two-thirds of my large music library is Hi-res and I spent years converting and laborously correcting tags and cover art yet I'm all for advancements as well popularity of streaming, MQA and all else that gives music lovers more choices. I'm old and won't be around that long, but exciting times lie ahead for music lovers and audio system enthusiasts. Love to jump in a time machine and see what best of music reproduction is like fifty years from now :-)

[scottsol]

I did comparisons between streaming some of Tidal's MQA and HD non-MQA versions of the same music stored on my server, and local won....

 

Depending on your hardware, it's configuration and your network infrastructure, the results may have reflected how optimized you were for internet streaming vs local playback rather than MQA vs straight Hi Res.

[revand]

Sorry if this is an amateurish question, I'm trying to understand if you will need to set up your software to decide how to pass the signal along. In other words, one user may want a signal bypassing any software decoding and passing it right to an MQA capable DAC while those without an MQA DAC would want more done by playback software. (like Chris's example with the Meridian Explorer DAC) Will there have to be some sort of toggle switch in software to direct it how the user wants it to handle MQA files? Could one, or would one, want to have a completely unprocessed MQA track sent to the DAC to do all processes (decoding, rendering, etc., etc) and if so, I am assuming the software will need to have some sort of option to do that? Hope that wasn't too confusing....

 

 

I made some charts how I interpret the different processes:

1. What is the quality of the music received with a device doesn't decode MQA?

2. How the original master sound quality is delivered using rendering?

3. How the original master sound quality is delivered using devices capable of full decoding MQA?

4. What sound quality can be achieved using an MQA device with a non MQA external DAC?

You can find them by clicking my name.

More thoughts can be found here

[bobbmd]

Chris-Excellent description of MQA. could you explain the 'pass through mode'? If I am using the ME2 am I supposed to to click pass through mode on(blue box in streaming on TIDAL) or should I leave it off? When playing a Master the blue light remains on on the ME2 either with/without the pass through and I don't really hear any difference in SQ.

[mansr]

Chris-Excellent description of MQA. could you explain the 'pass through mode'? If I am using the ME2 am I supposed to to click pass through mode on(blue box in streaming on TIDAL) or should I leave it off? When playing a Master the blue light remains on on the ME2 either with/without the pass through and I don't really hear any difference in SQ.

 

Passthrough on means the Tidal app sends the MQA stream directly to the DAC. With passthrough off the app decodes the MQA. Since your DAC supports MQA, it gets decoded either way, so there shouldn't be any difference in sound.

[ednaz]

Depending on your hardware, it's configuration and your network infrastructure, the results may have reflected how optimized you were for internet streaming vs local playback rather than MQA vs straight Hi Res.

Music server streaming via fiber optic USB to DAC, for both local music (on in-chassis hard drives) and MQA software decoding. MQA DAC replaced the Exasound e22 in one test, Exasound won. MQA software decoding to Exasound vs local high res, local high res won. Also tried it on my MacBook Pro, streaming vs high res, a couple of different small travel size DACs. My home network streams 2xDSD and DSF to more than one system so I'm pretty sure I'm not bandwidth constrained.

[scottsol]

Music server streaming via fiber optic USB to DAC, for both local music (on in-chassis hard drives) and MQA software decoding. MQA DAC replaced the Exasound e22 in one test, Exasound won. MQA software decoding to Exasound vs local high res, local high res won. Also tried it on my MacBook Pro, streaming vs high res, a couple of different small travel size DACs. My home network streams 2xDSD and DSF to more than one system so I'm pretty sure I'm not bandwidth constrained.

 

One possible issue is the quality of the network feed to the server, something that is bypassed with local playback. Speed is not the issue. The quality of the network infrastructure can have a major effect on sound quality e.g. Switches and Ethernet cables are very critical even when bandwidth is not an issue. A good way to remove this factor would be to send the local files to the server over your network, putting them and Tidal on equal footing.

 

Did you compare local and Tidal using the MQA DAC?

[papylon]

MQA? No thanks:

Schiit Audio, Headphone amps and DACs made in USA.

[ednaz]

One possible issue is the quality of the network feed to the server, something that is bypassed with local playback. Speed is not the issue. The quality of the network infrastructure can have a major effect on sound quality e.g. Switches and Ethernet cables are very critical even when bandwidth is not an issue. A good way to remove this factor would be to send the local files to the server over your network, putting them and Tidal on equal footing.

 

Did you compare local and Tidal using the MQA DAC?

I get that my wireless network may play a role somehow, but it's good enough to have MQA Tidal absolutely slay regular Tidal. However, in one of my comparisons, I streamed to my laptop from my music server on the same network that was streaming Tidal.

 

Even with the Explorer 2, 24/96 files played from my laptop were slightly better sounding than software decoded MQA on my laptop (with two different DACs) and than hardware encoded MQA from my laptop. (Using both Sennheiser and Fostex headphones.) Same was true if I wireless streamed from my main server via my laptop, which SHOULD make all things network equal. I could only find a few albums on Tidal where I know the production quality would be good enough for hearing a difference (and where I know the album really well), so again, there are limits on all this back and forth. An awful lot of hip hop, reggaeton, and rock these days would probably sound as good on an AM radio as they would HD on a DAC. Honestly, there were some albums where they sounded the same no matter what approach I was using - the loudness wars pretty much wrings the life out of music.

 

My conclusion is not that MQA isn't worth it. Absolutely is for Tidal streaming. But at some point the care taken in production when music gets re-mastered and turned into an HD file makes so much improvement that any other improvement is really a nudge and not a wow. At least for me, with the Explorer 2. Maybe different at the high end of DAC land.

[bobbmd]

Bryan-atta boy I have waited for the SQ that is available now all my life and thank God I didn't ruin my ears in the 60's keep all these hires/lossless/mqa type formats coming love 'em and will try them(if my CFO allows)

[labjr]

I get that my wireless network may play a role somehow, but it's good enough to have MQA Tidal absolutely slay regular Tidal. However, in one of my comparisons, I streamed to my laptop from my music server on the same network that was streaming Tidal.

 

Even with the Explorer 2, 24/96 files played from my laptop were slightly better sounding than software decoded MQA on my laptop (with two different DACs) and than hardware encoded MQA from my laptop. (Using both Sennheiser and Fostex headphones.) Same was true if I wireless streamed from my main server via my laptop, which SHOULD make all things network equal. I could only find a few albums on Tidal where I know the production quality would be good enough for hearing a difference (and where I know the album really well), so again, there are limits on all this back and forth. An awful lot of hip hop, reggaeton, and rock these days would probably sound as good on an AM radio as they would HD on a DAC. Honestly, there were some albums where they sounded the same no matter what approach I was using - the loudness wars pretty much wrings the life out of music.

 

My conclusion is not that MQA isn't worth it. Absolutely is for Tidal streaming. But at some point the care taken in production when music gets re-mastered and turned into an HD file makes so much improvement that any other improvement is really a nudge and not a wow. At least for me, with the Explorer 2. Maybe different at the high end of DAC land.

 

Seems like an accurate assessment. I think the difference will be smaller with a high end DAC. The DAC probably has more influence on the sound quality than whether it's MQA or not. Same with a good mastering. John Atkinson, editor of Stereophile Magazine, couldn't reliably choose the MQA over originals using his own recordings.

[audiventory]

Passthrough on means the Tidal app sends the MQA stream directly to the DAC. With passthrough off the app decodes the MQA. Since your DAC supports MQA, it gets decoded either way, so there shouldn't be any difference in sound.

 

As I understand, from Chris article software decoding is limited 1 time folding (i.e. 44/48 > 88/96). Full decoding hardware only.

[mansr]

As I understand, from Chris article software decoding is limited 1 time folding (i.e. 44/48 > 88/96). Full decoding hardware only.

 

With software decoding, a compatible DAC will do the final "unfold" which is just a very, very poor upsampling anyway.

[DanSmedra]

With software decoding, a compatible DAC will do the final "unfold" which is just a very, very poor upsampling anyway.

 

That's probably why the "final unfold" is so tricky/problematic for hardware manufacturers. Isn't their proprietary signal manipulation what distinguishes one DAC from another?

 

And that's why it's being repeated over and over...

 

"I guess. But hi-res isn’t a panacea for a poor recording or master though, is it?

 

No, it is not. A bad master cannot be corrected by MQA and a nicely mastered file streamed via good old Redbook will, all other things being equal, sound better than a dynamically compressed master streamed via MQA.

The things is: all things are rarely equal. It’s highly probable that a Redbook file converted to analogue by an Aqua La Scala MKII will easily better the SQ of that same song MQA-d but converted to analogue by an AudioQuest DragonFly." John Darko

[miguelito]

My conclusion is not that MQA isn't worth it. Absolutely is for Tidal streaming. But at some point the care taken in production when music gets re-mastered and turned into an HD file makes so much improvement that any other improvement is really a nudge and not a wow. At least for me, with the Explorer 2. Maybe different at the high end of DAC land.

Precisely. And to be clear, I don't see the streaming bandwidth improvement compared to an equivalent FLAC of similar resolution.

[Geoffrey Armstrong]

With software decoding, a compatible DAC will do the final "unfold" which is just a very, very poor upsampling anyway.

Perhaps this is a stupid question; but if the final "unfold" is "just a very, very poor up-sampling" then why would some files report higher sample rates after the final "unfold" than others on an MQA DAC?

[mansr]

Perhaps this is a stupid question; but if the final "unfold" is "just a very, very poor up-sampling" then why would some files report higher sample rates after the final "unfold" than others on an MQA DAC?

 

The MQA file tells the DAC what the original sample rate was, and this is what is displayed. No content above 44.1/48 kHz is actually preserved by the MQA compression.

[DanSmedra]

The MQA file tells the DAC what the original sample rate was, and this is what is displayed. No content above 44.1/48 kHz is actually preserved by the MQA compression.

Let's see if I'm following your claim correctly. The original article by Chris and MQA's website show the signal between 48kHz to 96kHz is losslessly "encapsulated" and "folded back into" the core MQA file.

 

What do YOU mean by "actually" preserved? Are you saying that the band of the signal that's losslessly compressed and decompressed is never "actually preserved" (semantics) or doesn't even exist at all on playback? If the latter, you're claiming Chris and MQA's explanation are fraudulent?

[mansr]

Let's see if I'm following your claim correctly. The original article by Chris and MQA's website show the signal between 48kHz to 96kHz is losslessly "encapsulated" and "folded back into" the core MQA file.

 

What do YOU mean by "actually" preserved? Are you saying that the band of the signal that's losslessly compressed and decompressed is never "actually preserved" (semantics) or doesn't even exist at all on playback? If the latter, you're claiming Chris and MQA's explanation are fraudulent?

 

Consider a 48 kHz 24-bit MQA file. The high 15 bits of this file are a reasonable representation of the 0-24 kHz frequency band from the original while the low 8 bits contain a compressed version of the 24-48 kHz band. The "core" decoder decodes the low 8 bits and combines this information with the base band signal from the high bits to produce a 96 kHz sample rate output covering the 0-48 kHz frequency band. Compared to the original file, this decoded version comes pretty close, but there some losses in the high half (24-48 kHz). If the original file had a sample rate higher than 96 kHz, any frequency content above 48 kHz will have been completely discarded. The "render" part upsamples the output of the "core" decoder to the same rate as the original file. Because of the terrible interpolation filter, it may at first glance look like some high-frequency content has been restored here, but it is all fake. All you actually get is images of the lower frequencies and a rising level of dither noise.

[Jud]

If the original file had a sample rate higher than 96 kHz

 

 

Should we take from this that no actual musical/harmonic content above 48KHz would be preserved in an MQA file encoded from a 192KHz original? (I'm guessing my speakers don't have usable response even up that far, but just asking.)

[mansr]

Should we take from this that no actual musical/harmonic content above 48KHz would be preserved in an MQA file encoded from a 192KHz original? (I'm guessing my speakers don't have usable response even up that far, but just asking.)

That is exactly what I'm saying.

[Jud]

That is exactly what I'm saying.

 

Thanks. I personally wonder whether there is much actual content above 48KHz on hi res recordings; I'm just happy that the product doesn't have to be taken all the way down to 16/44.1, very possibly with a system that is not terribly high fidelity. (This of course is no assurance that a hi res product will be high fidelity, it just eliminates one possible way of screwing things up.)

 

But if we want to minimize the number of conversions between us and the studio, MQA doesn't help in that regard.

 

 

The benefit I've heard from MQA so far consists of the release for streaming of better masterings of some recordings.