MQA is Vaporware

[Rt66indierock]

1 hour ago, FredericV said:

Last weekend we were an exhibitor at the X-FI 2017 show in The Netherlands where our server was being presented in three rooms, including our own demo room where we had carte blanche. We had a lot of fun playing both audiophile and real music including Manley based masters from Jazz Profilactika, a befriended new Jazz band, from which we received their 24 bit master files one day before the show.

We also did a little test with MQA files from 2L.no

Demonstrated using Antelope's Platinum DAC + separate 10M atomic clock + separate Voltikus, and the excellent active John Watkinson speakers which are not very well known, but among the best which I have heard so far.

https://www.flickr.com/photos/147070590@N02/36730762584/in/dateposted/

The co-designer of the Legends is Kommer Kleijn, a "professor" type of guy who is also a respected 3D stereographer
http://www.kommer.com/

 

The lead designer is the guy who wrote the "bible" about digital audio:
https://www.amazon.co.uk/Art-Digital-Audio-John-Watkinson/dp/0240515870

 

I have no affiliation with this speaker brand except that they make a great demo partner. I have no affiliation with Antelope either, in the past we were reseller for a couple of years until we decided to go into the music server business. I now use Metrum Adagio for my own test & dev. I list the specs so that others won't say our system is not revealing enough to do such test. We also fixed the flutter echo of the room using acoustic panels. Just to make the test setup right.

 

Just before the end of the show on Sunday, we played the following test on our server:

1. DXD master from 2L.no, a classical piece
2. mqa version of the above, with a live version of the sox method as disclosed on Darko's site.

We tried to make this test as blind and unexpected as possible, so after the DXD file played (a classical piece), we said we were going to play a different version of the same file. So we played the upsampled MQA version, than asked if they could hear the difference.

They could not. I begged them to please reveal any difference, if any ... nobody in the room was able to tell them apart.

So for me, this is case closed. Why waste any more time with MQA or trying to figure out the secret parts, if the sox method can do the above? The MQA people will fight us and say sox is not the real thing, but sox is pseudo MQA just like what Auralic is doing. But who cares if we achieve the above. The end result is what counts. MQA fans always say our hearing is analog and the number of bits don't matter, and the end result is what's count.
 

Another eye opener was that an AES engineer which I heard talking about MQA in a Chinese restaurant in Veldhoven and later was in the bar of our conference center, told me our hearing has 5µs of temporal resolution based on the fact that we can locate a sound source with 2 to 3 degrees of accuracy and a calculation based on the distance of sound sources, he explained how he came to this number. I was too tired to completely remember how he did that calc.
 

The 50µs that MQA is claiming is not enough. He explained that for a true end-to-end system that can duplicate the in air response of a source, it would need a microphone that can capture much higher frequencies, and the samplerate would have to be much higher than 192K to achieve 5µs. He calculated that it would at least need an analog bandwidth of 200 Khz, so sampling at 384K won't even cut it. It would also require microphones that can capture all the harmonics of S-sounds and cymbals, which cannot be seen in regular spectral plots, as they average because of the integration window and these transients are very short.

It's like measuring the average sound level of an airport at night, when only a few planes fly by and keep you out of your sleep. The average will still not show this.

He was present at an MQA introduction show using very expensive speakers and being demo'ed by Hans Beekhuyzen. He told me the S sounds are all wrong with fully decoded MQA, and that he would never dare to give such a bad demo. This demo was at a very well respected ultra high-end boutique dealer.
 

The interesting part about this AES engineer is that he sent all his remarks to Hans and another well known MQA opinion maker, but Hans completely ignored this. We talked for more than an hour, maybe this guy can post his technical arguments, I still have his card

But for me, this is now case closed. I'm happy that thanks to MQA I put a lot of effort in tweaking our own DSP and I learned so much more about filters, and that we found the sox method and it's correct settings which we posted on Darko, so other devs can start using it. But I'm not a fan of their anti-ringing and weird filters that try to clean up post-ringing.

I also briefly talked to the leading MQA opinion maker in the Netherlands. He also visited our room, liked the sound. Shook hands and got a message on FB today that he wanted to cease fire.

We won't change these people. It is pointless. They won't change my opinion. The fact that we have topics like this is good as this discussion is kept away from the regular press, but in talking with the MQA people, at a certain point, there is nothing new to bring.

This is the reason why the topic at gearslutz was locked: they landed into name calling.

Let's agree to disagree and shake hands.

 

 

My intent of writing "MQA is Vaporware" was and is to keep MQA out of studios and away from artists. That job is not done. I am going to RMAF 2017 and we will see what the mood is. In the United States there can be no cease fire until John Atkinson and Robert Harley stop promoting it. 

[The Computer Audiophile]

1 minute ago, Rt66indierock said:

there can be no cease fire until John Atkinson and Robert Harley stop promoting it

 

I hope you have a lot of bullets :~)

[Rt66indierock]

4 minutes ago, The Computer Audiophile said:

 

I hope you have a lot of bullets :~)

 

900 rounds a minute should do the trick. Don't Forget The Guns from Cheryl Wheeler's Driving Home album

The MQA debate has always seemed like desperation to me. That suspicion was confirmed in the responses in "Politics of MQA" this is our best hope etc. 

[Mordikai]

6 minutes ago, The Computer Audiophile said:

 

I hope you have a lot of bullets :~)

haha! yes - the war metaphors are a bit much.

I don't think the critical discussions in a few internet chat rooms have much to do with the success or failure of MQA. I really don't know if it's dying or just laying ground work at this point. I personally have found it pointless from the beginning in that it solved non of the problems I have in audio.

[crenca]

29 minutes ago, Rt66indierock said:

 

My intent of writing "MQA is Vaporware" was and is to keep MQA out of studios and away from artists. That job is not done. I am going to RMAF 2017 and we will see what the mood is. In the United States there can be no cease fire until John Atkinson and Robert Harley stop promoting it. 

 

Rt66indierock,

 

Given their subjectivist, "high end is like wine and art" philosophy I don't see them conceding defeat.  Years from now you will read them justifying MQA based on their idiosyncratic SQ assessment.  Since they simply don't acknowledge or care about the technical, consumer and industry impact of MQA they will just continue to ignore it.

 

That said, today (it changes day to day  ) I am optimistic because the consumer reaction (in the comment section) to TAS "political" article is very negative.  Only a handful seemed in anyway bamboozled by MQA.  The one real industry participant (Mr. Ritter of Berkeley Audio) had to resort to an explicit "I am somebody, you guys are nobodies" confidence game.  

 

The next phase in MQA's strategery appears to be more niche space streaming roll outs such as the coming HDTracks Hi Res MQA service.  But the target audience, the audiophile, is catching on.  Will they actually sign up in sustainable numbers?  So barring a major streaming player picking up MQA, what exactly is going to be MQA's breakthrough moment?  

[Rt66indierock]

2 minutes ago, Mordikai said:

haha! yes - the war metaphors are a bit much.

I don't think the critical discussions in a few internet chat rooms have much to do with the success or failure of MQA. I really don't know if it's dying or just laying ground work at this point. I personally have found it pointless from the beginning in that it solved non of the problems I have in audio.

 

Did you listen to the song? It's not about war. You are both right and wrong about the vaporware thread. It has had influence but I'm just letting you know what is going on to keep MQA out of studios. As for ground work read my posts in "The Politics of MQA" (posted as Steve).

[Rt66indierock]

7 minutes ago, crenca said:

 

Rt66indierock,

 

Given their subjectivist, "high end is like wine and art" philosophy I don't see them conceding defeat.  Years from now you will read them justifying MQA based on their idiosyncratic SQ assessment.  Since they they simply don't acknowledge or care about the technical, consumer and industry impact of MQA they will just continue to ignore it.

 

That said, today (it changes day to day  ) I am optimistic because the consumer reaction (in the comment section) to TAS "political" article is very negative.  Only a handful seemed in anyway bamboozled by MQA.  The one real industry participant (Mr. Ritter of Berkeley Audio) had to resort to an explicit "I am somebody, you guys are nobodies" confidence game.  

 

The next phase in MQA's strategery appears to be more niche space streaming roll outs such as the coming HDTracks Hi Res MQA service.  But the target audience, the audiophile, is catching on.  Will they actually sign up in sustainable numbers?  So barring a major streaming player picking up MQA, what exactly is going to be MQA's breakthrough moment?  

 

And how did I deal with Michael Ritter? The comments are posted under Steve

[crenca]

11 minutes ago, Rt66indierock said:

 

And how did I deal with Michael Ritter? The comments are posted under Steve

 

Ah!  Be sure to post your impressions after you meet up with Mr. Quint at RMAF (I unfortunately won't be going this year).  I would be interested in what he thinks about the reaction to his reaction to the reaction of MQA

[FredericV]

1 hour ago, crenca said:

 

 

Thanks for the write up Frederic.  Just to be clear, the active speakers do not have a DAC (and thus a 2nd A>D>A conversion) correct?

The speakers have XLR & IEC power inputs at the bottom. Internally every speaker has four amps.
All processing / filtering is in the analog domain. There is no extra AD/DA

 

[Mordikai]

1 hour ago, Rt66indierock said:

 

Did you listen to the song? It's not about war. You are both right and wrong about the vaporware thread. It has had influence but I'm just letting you know what is going on to keep MQA out of studios. As for ground work read my posts in "The Politics of MQA" (posted as Steve).

What song? I've read everything you've posted. I have no gripe with you.

[Rt66indierock]

1 minute ago, Mordikai said:

What song? I've read everything you've posted. I have no gripe with you.

 

Don't Forget the Guns by Cheryl Wheeler. It's on YouTube.  If you don't get the reference after listening to the song...

 

Rolling back the tape my opening bullets at MQA and the people supporting it  were about "Riders on the Storm"  around the time of the T.H.E.Show in Irvine last year. I squeezed a few more rounds off in the comments to Listening #166. You should be able to figure out what they are. 900 rounds a minute is a reference to I can ask more questions than you can answer.

 

I think what I've written since the middle of last year has been worth reading unless you are supporter of MQA.

[#Yoda#]

You should consider that the excitement about MQA in HiFi publications and forums is primarily an US based phenomenon. In general in the European HiFi press or forums, MQA is not really a big deal, more a peripheral matter.

 

We shouldn't blow up an artificial bubble about a temporarily hyped trial to dominate and control music distribution. Mainstream customers do not visit this forum or notice other audiophile publications. It is essential to bring the bare facts about MQA to other popular media platforms and prevent guided misinformation.

 

 

[Don Hills]

7 hours ago, FredericV said:

... Another eye opener was that an AES engineer which I heard talking about MQA ...

 

He appears to be confusing two points. One is the sample rate required to accurately capture content containing frequencies up to 200 KHz. He's arguably correct, but how much music contains such frequencies at a level loud enough to be theoretically audible? There's also no evidence that such frequencies are directly audible, and plenty of evidence that by the time they get to the microphone they have been greatly attenuated by the air, and in any case they should not be reproduced (intermodulation, amplifier or speaker damage).

The other point is the actual time resolution. You don't need ultrasonic frequencies or massive sample rates to capture signal timing to an accuracy far greater than is audible. Even 44.1/16 sampling can capture timing to an accuracy as small as 55 picoseconds. To put that in perspective, light travels less than an inch in that time.

[darkmass]

4 hours ago, Don Hills said:

Even 44.1/16 sampling can capture timing to an accuracy as small as 55 picoseconds. To put that in perspective, light travels less than an inch in that time.

 

Could you show us your arithmetic on that?  Light in your dimension seems a wee bit slow.    

[Fokus]

13 hours ago, FredericV said:

Another eye opener was that an AES engineer which I heard talking about MQA in a Chinese restaurant in Veldhoven and later was in the bar of our conference center, told me our hearing has 5µs of temporal resolution based on the fact that we can locate a sound source with 2 to 3 degrees of accuracy and a calculation based on the distance of sound sources, he explained how he came to this number. I was too tired to completely remember how he did that calc.

 

That the inter-aural time acuity of the auditory system is about 5µs has been common knowledge for at least 50 years, probably much more.

 

You can easily test it by pulling a mono track into a stereo DAW, replay over headphones, delay one channel relative to the other by Nµs and listen for a shift of the central image.

 

Or you could listen to the output of a stereo analogue tape machine while tweaking azimuth ;-)

 

Or you could try to set up a pair of utterly identical speakers in an utterly symmetrical room. If you have utterly symmetrical ears then you'll find that you'll need to position the speakers with cm accuracy.

 

13 hours ago, FredericV said:

The 50µs that MQA is claiming is not enough. He explained that for a true end-to-end system that can duplicate the in air response of a source, it would need a microphone that can capture much higher frequencies, and the samplerate would have to be much higher than 192K to achieve 5µs.

 

MQA do not want 50µs. In the 2014 papers they express a desire for 3µs, but are prepared to settle for 10µs for practical reasons.

 

However, all of this is still based of two mistakes (or two distortions of facts):

 

1) the 5µs figure holds for inter-aural sound, i.e. the difference in time of a single acoustic event in two different channels. This figure thas nothing to do with any mysterious monaural acuity that hifi companies and hi-res proponents claim to exist.

 

2) in order to resolve the location of an event in time with µs accuracy a MHz sampling rate is not required. As said earlier the temporal location accuracy of 44.1kHz at 16 bit is of the order of hundreds of picoseconds. The requirements for this are a sufficientlt-high signal to noise ratio, and correct anti-aliasing and anti-imaging filtering. Sampling rate plays a relatively minor role in this story.

 

[esldude]

2 hours ago, darkmass said:

 

Could you show us your arithmetic on that?  Light in your dimension seems a wee bit slow.    

I have it at .65 inches at lightspeed for 55 picoseconds.  

 

186282 miles per second x 5280 ft per mile times 12 inches per foot =  11,802,827,520 inches per second.

 

Divide by 1 trillion and multiply by 55 and you get a bit over .65 inches per 55 picoseconds.

 

Alternatively 299,752,458 kilometers per second times 1000 for meters per second times 39.37 inches per meter divided by 1 trillion and multiplied by 55 results in about the same .65 inches per 55 picoseconds. 

[darkmass]

3 hours ago, esldude said:

I have it at .65 inches at lightspeed for 55 picoseconds. 

 

Interesting.  However, somehow I'm still missing something.  Yeah sure, 55 picoseconds maps to light speed ~0.65 inches.  Done.

 

What's missing is the '44.1k sampling can capture timing to as small as 55 picoseconds' part.

 

Is that "can capture" as in assuming only under very specific but limited circumstances?

 

Or is it the following:

 

Assuming samples every 1/44100 second and assuming--though k0, k1, x, m, and d are strictly in the digital sampling space domain--(however, we are listening in a strictly sample based analog reconstruction of the digital sampling space), that the following holds true...

 

Let sample k0 = x + m/44100 seconds,

let sample k1 = x + (m+1)/44100 seconds, (that is, the next sample after the sample at time k0)

 

and let d = 55 picoseconds,

 

then for all t, such that k0 < t and t+d < k1,

 

an event at time t can be distinguished through typical human hearing from the identical event if the identical event occurs at time t+d?

 

 

If at all possible, please cite credible authoritative references.

[Hifi Bob]

2 hours ago, darkmass said:

 

Interesting.  However, somehow I'm still missing something.  Yeah sure, 55 picoseconds maps to light speed ~0.65 inches.  Done.

 

What's missing is the '44.1k sampling can capture timing to as small as 55 picoseconds' part.

 

This might help: Practical demonstration that Redbook’s timing resolution is not greater than 1 nano-second.

 

[mansr]

2 hours ago, darkmass said:

What's missing is the '44.1k sampling can capture timing to as small as 55 picoseconds' part.

It is a common misunderstanding that the sampling rate determines the time resolution. The sampling theorem states that a band-limited signal can be exactly reconstructed if the sample rate is higher than twice the bandwidth. Now this assumes infinite precision in the samples, which of course isn't the case with 16-bit or 24-bit audio. A finite precision does introduce a small error. However, and this is the crucial part, this error is unrelated to the sample interval.

 

Imagine a sine wave sampled at regular intervals. Now nudge the sine wave sideways just a little bit. Notice that the values at all the sample points have changed. If these changes are greater than the value of the least significant bit, they will be recorded.

 

So what is the minimum detectable time shift, you may ask. The answer is that it depends on the frequency of the signal. The amount by which a sample value changes with a given time shift depends on the slope of the signal around the sample point. Higher frequencies have steeper slopes and thus smaller displacements can be recorded.

 

Going back to our sine wave, we observe that it has the steepest slopes at the zero crossings. With a vertical scale of [-1, 1], this maximum slope for a sine wave of frequency f is 2πf. Let d be the smallest recordable difference in sample values. In the immediate vicinity of the zero crossing, the sine wave can be approximated by a straight line, so we are looking for the time t at which 2πft = d. This is easily solved as t = d / 2πf. For a sample precision of b bits, there are a total of 2^b steps from -1 to +1, so the size of one step is d = 2 / 2^b. Substituting this into the previous equation, we get t = (2 / 2^b) / 2πf = 1 / (πf * 2^b). With 16-bit samples and a 1 kHz sine wave, the smallest detectable time shift is thus t = 1 / (π * 1000 * 65536) or slightly less than 5 nanoseconds. At the highest possible frequency for 44.1 kHz sampling, 22.05 kHz, the figure drops to 220 ps. I don't know how someone arrived at 55 ps. Perhaps they used the sample rate rather than the Nyquist frequency and forgot that the 16 bits cover both the positive and negative values.

 

Note that the minimum detectable time-shift at a given frequency does not depend on the sample rate, only on the bit depth.

[esldude]

1/(2pi x number of levels x sample rate)

 

Which works out to near 55 picoseconds for redbook.  This without dither as dither works like additional levels between zero and the LSB. 

[mansr]

9 minutes ago, esldude said:

1/(2pi x number of levels x sample rate)

 

Which works out to near 55 picoseconds for redbook.  This without dither as dither works like additional levels between zero and the LSB. 

Where did you get that formula? It doesn't agree with my derivation above.

[esldude]

9 minutes ago, mansr said:

Where did you get that formula? It doesn't agree with my derivation above.

I don't remember for certain.  I think I saw it mentioned first by JJ Johnston.  I also have seen it in a paper by Robert Stuart from the 1990's about the parameters of what was possible in digital recording.  It did seem to me the sample rate was incorrect and should have been Nyquist instead when I did the same derivation you have done. And also that it would be dependent upon the frequency of the signal.  Also that such derivations are for maximum signal levels.  And yes, the values are 65,536 in total, but go from zero to plus 32,768 and minus 32,767.  I did think you end up with 110 picoseconds instead of 220 because once the sample is above half the LSB it will get recorded as one LSB. 

[Jud]

11 hours ago, Fokus said:

correct anti-aliasing and anti-imaging filtering

 

It would make good ADC filtering easier, I imagine, if decimation to 44.1k sample rate hadn’t been baked in by the old silver-disc distribution system.  But we have what we have.

[mansr]

32 minutes ago, esldude said:

I did think you end up with 110 picoseconds instead of 220 because once the sample is above half the LSB it will get recorded as one LSB.

Good point. Too late to edit my post now though.

[Ralf11]

186282 miles per second is c for a vacuum

 

is it in a vacuum?