Blue or red pill?

[mansr]

1 hour ago, manisandher said:

My understanding is that although Mans is Swedish, he currently lives in the UK. Otherwise, I hope Ryanair will come to the rescue.

I live in Southampton, and I accept the invitation. There's even a direct train.

[mansr]

Just now, manisandher said:

Well, I am very pleasantly surprised. I'll send a PM.

I'm open to experimentation. Hopefully we'll learn something. I promise I don't bite.

[mansr]

2 minutes ago, kumakuma said:

Looking forward to hearing the results of this.

I'll bring some recording equipment.

[mansr]

51 minutes ago, manisandher said:

Recording the output from my DAC/speakers to try to understand how two identical files sound different on playback would be far more interesting.

 

45 minutes ago, kumakuma said:

Wouldn't capturing the output with an ADC make more sense?

 

My idea is to capture anything that can be captured, be it digital, analogue or acoustic. What is feasible obviously depends on the system.

[mansr]

2 hours ago, manisandher said:

@mansr, we have two choices for setups:

 

1. use my regular Phasure USB DAC

- the best sound quality

- will need to interpolate to 705.6/768 in XXHighEnd/HQPlayer

- will not allow us to capture the digital output of the audio PC (unless you have an ADC that accepts a 24/768 USB input), which might restrict analysis of exactly what is going on

- we will have to accept that in copying a file from my NAS to a local folder on the audio PC, the file really is the same (I totally accept that this is the case - it's during replay that 'weird' things seem to happen)

 

listening setup:

 

recording setup:

 

 

2. use an spdif DAC that I have here

- not as good as Phasure but good enough for the job (I've already tried)

- will need to interpolate to 176.4/192 in XXHighEnd/HQPlayer

- will allow us to capture the digital output of the audio PC (using the Tascam DA-3000 I have here, or any other ADC with an spdif input you care to bring)

 

listening setup:

 

recording setup:

 

I want to capture the digital output of at least one supposedly different-sounding pair. Is there any reason for not running the DAC outputs into the ADC and amps at the same time?

 

Quote

In either case, as I suggested earlier,  I'm happy to do a paired comparison between the two files. Mans, you could control the playback software out of sight from me, with 3 choices (I had suggested 4 earlier, but this would be easier for me):

 

1. A,B=same (either NAS or local)

2. A=NAS, B=local

3. A=local, B=NAS

 

I don't mind how many pairs we go through (within reason). If I get >70% correct, I think it's reasonable to assume that I really am hearing a difference. (Of course, if this is the case, I hope Mans hears things the way I do too.) We can then go on to recording outputs and trying to figure out what's going on.

Why not a standard A/B/X protocol?

[mansr]

22 minutes ago, manisandher said:

Yep, lots of reasons:

- we'd have to use a splitter

- or a preamp, which I'd really rather not do)

- the ICs to the mono amps are quite long and if we're using the spdif DAC (which looks like the one we're going to go for), I wouldn't trust it to have a beefy enough output stage to carry it off.

How about using the ADC in monitor mode between the DAC and amps? That way we'd be certain that we're hearing exactly what the ADC is picking up.

 

22 minutes ago, manisandher said:

- the audio PC and DAC sit in my basement, only the monos and speakers in my listening room - would make listening and recording simultaneously pretty much impossible

There are ways.

 

35 minutes ago, manisandher said:

Talk me through the procedure.

1. Play sample A.
2. Play sample B.
3. Play A or B randomly, you decide which it is.

[mansr]

2 minutes ago, manisandher said:

If this is to aid in "how to really test this", then I'm all for it.

 

When I stream a file from Tidal and then listen to the exact same file on my NAS, they sound different to me. I'd like to demonstrate this to Mans. Let's say Mans agrees that they do indeed sound different. The obvious question then is: how do we know they're exactly identical? I can say, "because I say so", but that's not very convincing. I'd be quite happy to play the files back and capture the digital output of the audio PC and the analogue output of the DAC with the recorder.

 

Once Mans has verified that the two digital captures are identical (which they will be - I've done it many times already) and that the two analogue captures are virtually identical, within a small error (slightly drifting ADC clock, etc.), then Mans should be satisfied that the two files were indeed identical.

 

The thinking can then begin...

Do you expect to hear a difference yet get identical captures from the ADC? If so, do you suppose a microphone would register the difference?

 

2 minutes ago, manisandher said:

But if an A/B/X (the procedure for which I now understand) would be helpful, I'm happy to oblige. I could pick a few tracks that I think I'd be able to identify and we could see how I do. But I'd really, really prefer for this not to become to main focus of Mans' visit.

If I don't hear a difference, this is probably the most effective way of convincing me that you do. Conversely, if you fail to do better than random chance, perhaps you'll reconsider what you're actually hearing. If I do hear a difference, I'll definitely want to understand what's causing it.

 

Of course, we should both remember that nobody is on trial here. This should be nothing more than a fun experiment in the hopes that at least one of us learns something.

[mansr]

4 hours ago, manisandher said:

(What I write below has nothing to do with MQA - I've already stated that I'd be happy for MQA to remain a niche.)

 

Stuart believes that:

- "time is 5-13x more important than frequency"

- "what looks like high frequency on a FFT is actually temporal microstructure in the audio itself"

- "our hearing is in fact incredibly acutely sensitive to microstructure in the mid-range and to typically quiet sounds"

 

Let's assume all this is true for now. A microphone should have no problem picking this 'temporal microstructure' up, but the ADC will screw it up if it's smoothing* this 'microstructure' up in any way. In which case yes, I can imagine a scenario where I hear a difference but get identical captures from the ADC.

 

*I believe all the ADCs I've owned and still own do this to varying degrees.

"Temporal microstructure" isn't an engineering term and means nothing, but fine, let's pretend it's a real thing. If you can hear it in the playback, this means it is present in the recording, the recording which was captured by an ADC. If you can hear it, it also means the DAC is reproducing it. Why then would an ADC not be able to capture it again? I'm assuming an ADC of good quality, of course.

[mansr]

1 minute ago, manisandher said:

Let's continue our 'pretending' and assume the MQA guys are onto something; that this microstructure is indeed present in a recording captured by many/most/all ADCs, but that it needs to be 'deblurred' to make an audible difference.

I thought we weren't talking about MQA.

[mansr]

3 minutes ago, pkane2001 said:

Ok, just want to make sure that the same player software is used, with the same settings, when doing A/B comparisons -- there's a lot a player can do to the bits before these are sent out to the DAC, even if the source files are exactly the same.

The digital output will be captured and compared.

[mansr]

36 minutes ago, Ralf11 said:

"Temporal microstructure" ... means nothing, but could mean something 

That's what makes it so insidious.

 

36 minutes ago, Ralf11 said:

I wonder if it could be analogized (not to just resolution or pixel count) but to micro-contrast in optics...

Drawing analogies between audio and imaging is fraught with peril as there is no acoustic equivalent to the optical lens.

[mansr]

10 minutes ago, esldude said:

Yes, exactly. 

 

You can take a still photo and look at it in optics even though your eye never really sees it quite this way.  There is no equivalent still unchanging way to record audio and hear it in one instant.  You can look at a photo, take your time shift your attention.  Audio is not amenable to doing that with your ear.  

It's worse than that. Due to the optical focusing system, an image has distortions with no equivalent whatsoever in a sound recording. That said, there are valid comparisons to be made. For example, aliasing from undersampling might be seen as a moiré pattern in an image a brick wall.

[mansr]

Just now, adamdea said:

After all the bits don't stay completely still even on your nas do they? ie the file keeps changing...

What now?

[mansr]

38 minutes ago, manisandher said:

Mans has stated that he's keen to capture the digital output of the audio PC, so we'll do that. We can also capture the analogue output from the DAC, if that might be useful.

 

I'm going to look into the possibility of capturing the output of the audio PC in real time. I'm going to try a BNC splitter at the audio PC and feed one spdif cable to the DAC, another to the ADC, and then set the ADC to auto record. My main concern is that this doesn't affect the signal reaching the amps. If I'm happy it doesn't, we'll do things this way.

The first step is to verify that the digital signal into the DAC is unchanged. If a difference can be heard, this should be detectable in the analogue output of the DAC.

 

38 minutes ago, manisandher said:

But I definitely don't want to capture the analogue output of the DAC in real-time. For this, we'll simply replay the files exactly as we did when listening to them.

I think it's worth checking if the DAC can drive both the ADC and the amps at the same time. The input impedance of both should be fairly high. If that doesn't work, we could try connecting the DAC to the ADC input and its monitor output to the amp. If the alleged difference can be heard in this configuration, it really ought to have been captured by the ADC.

 

38 minutes ago, manisandher said:

We can also think about capturing the sound from the speakers in real time with a microphone->ADC.

Do you have some decent microphones?

 

38 minutes ago, manisandher said:

All this assumes that either Mans hears a difference, or if not, that I can prove I hear a difference through an A/B/X. If neither of these is the case, taking a digital, analogue or microphone capture is moot.

If I hear a difference, I'll definitely want to record it. If you can't prove you hear it, will you concede that there is in fact no difference to be heard?

[mansr]

13 minutes ago, pkane2001 said:

Thanks for the explanation. Of course, high precision timers are available and should be used (for example, the HP counter on my audio PC, built about 4 years ago, has the frequency of 14.3 MHz).

You don't need high precision timers to play back audio. In fact, you don't need timers at all.

[mansr]

15 minutes ago, sandyk said:

If you succeed, the only person that you MAY convince is mansr, in which case I feel sure that he will do further investigations.

If I become convinced there's a difference, I will certainly attempt to figure out why.

[mansr]

5 minutes ago, pkane2001 said:

And that's why Mans is such a good test subject for this: he'll be curious enough to dig in deeply to find the reason for audible differences (if any), and he'll collect enough data and evidence so that others could help him, right, Mans?

I'll try. Well, if I hear the difference, that is. If I don't, I still hope to get some recordings of what Mani assures us sounds different.

[mansr]

3 hours ago, PeterSt said:

You will be able to show a difference in SQ, but you both will fail on the explanation. You just won't know what is going on where and when.

Please drop the elitist attitude. If you think you know something, explain it or shut up.

[mansr]

1 minute ago, Spacehound said:

Computers and operating systems and sometime languages. I don't do it all by myself, obviously..

 

Currently I'm a very small part of a totally new concept where time doesn't come into it and  operations are not 'sequential'. Everything is set up and then done in one instant (as far as we can tell) go,  no matter how complicated.

It has now  got to the point where it is under test by a number of 'Fortune 500' corporations and has already done stuff impossible before as it would have  taken longer than the predicted future existence of the universe. . 

If you're talking about quantum computing, why don't you just say so?

[mansr]

Just now, PeterSt said:

This is no wonder for someone who is in love with his ADC. He just can't have it that I am telling him it doesn't work like that.

Why don't you tell me how it (not quite sure what you're referring to here) does work?

[mansr]

1 minute ago, Spacehound said:

As he had a go a Peter too I think he's  a touch scratchy this morning.

Peter loves telling everybody they are wrong, but he never offers anything but vagaries himself. Today he went a step further, insinuating that I wouldn't ever be able to understand how "it" works. I found that a tad insulting.

[mansr]

5 minutes ago, PeterSt said:

Can you quote the part where I said that at first.

I already did.

 

[mansr]

8 minutes ago, PeterSt said:

That is out of context. What about reading the whole post, including lead in and lead out. Get the gist of Mani already having a mistake in the base and you and him clearly won't be able to cope because of not knowing sufficiently about the internals of the software which I wrote and of which I claim that neither of you won't be able to judge what is happening for real because I already wouldn't know answers.

You're basically saying that if you don't know something, then nobody can. How is that not elitist?

[mansr]

21 minutes ago, PeterSt said:

Yes "it". You put the quotes there. What are you talking about there ?

There is nothing such as "it" nor did I imply any it or whatever you call vague because you don't believe in any of this in the first place.

"This" what ? right, all of "it".

 

Are we getting somewhere now ?

If I explicitly tell (you) that no ADC is going to show any of this because two subsequent captures of analogue will be different no matter how hard you try to have them the same, you plainly don't believe me. Do I have that right ?

It is there where you start to call me vague. Where I am keen on telling everybody that they are wrong has to be between your ears.

Has anyone ever asked you to calm down?

[mansr]

15 minutes ago, PeterSt said:

No.

That explains a lot.