Blue or red pill?

[Confused]

9 minutes ago, pkane2001 said:

 

What you’ve missed is that no analysis or review of the data has been published yet, so any conclusions about immesurability are premature. The rest of what you’ve posted is correct.

Thanks, noted. 

[Summit]

1 hour ago, manisandher said:

 

 

I was suggesting that it might be impossible to block certain noise getting into the DAC, without blocking the signal itself. In which case, the only choice is to manipulate the noise getting through to the DAC, in a sonically advantageous manner.

 

Hope that's clearer now.

 

Mani.

 

Yes it’s next to impossible to block certain noise to getting into the DAC. It may be obvious but still the best is to never let the noise get to, in or even near the data or audio signal in the first place. To do that one need to keep all the noisy data processing and power supplies, monitors etc. separated and as far you can from all delicate audio gear/components as possible. So all computer gear placed in another room and on another mains power line.  

[manisandher]

1 hour ago, Summit said:

To do that one need to keep all the noisy data processing and power supplies, monitors etc. ...

 

The way I see things is that there are two types of noise that can enter the DAC along with the digital signal:

 

1. extrinsic noise - from power supplies, monitors, etc

 

2. intrinsic noise - generated during the data processing of the digital signal itself in the source*

 

The former you can minimise by taking the precautions you outline. The latter is embedded into the digital signal and can't be filtered out without affecting the signal. It you can't eliminate it, you want to manipulate it in a way that helps.

 

But I have to say that I'm no digital audio engineer, and that this is just the way I see things. There could well be other explanations as to how bit-identical playback could sound different, and I'm totally open to hearing them.

 

*I don't think this is an issue exclusive to computer audio. Having used a separate CD transport and DAC for many years, I'm well aware that bit-identical playback can sound different there too.

 

Mani.

[Summit]

2 hours ago, manisandher said:

 

The way I see things is that there are two types of noise that can enter the DAC along with the digital signal:

 

1. extrinsic noise - from power supplies, monitors, etc

 

2. intrinsic noise - generated during the data processing of the digital signal itself in the source*

 

The former you can minimise by taking the precautions you outline. The latter is embedded into the digital signal and can't be filtered out without affecting the signal. It you can't eliminate it, you want to manipulate it in a way that helps.

 

But I have to say that I'm no digital audio engineer, and that this is just the way I see things. There could well be other explanations as to how bit-identical playback could sound different, and I'm totally open to hearing them.

 

*I don't think this is an issue exclusive to computer audio. Having used a separate CD transport and DAC for many years, I'm well aware that bit-identical playback can sound different there too.

 

Mani.

 

The noise will not become embedded into the digital signal if the data processing, the power and the whole room would be noise free. Ok? But that’s impossible so the best is to never let any noise geting even near the data or digital signal in the first place.

 

Step 1. Let’s remember that noise are by-products generated from various types of transmissions, power regulations, data and signal processing, PSUs etc etc. If we would make all signal processing with only a noise profile that’s much higher than the digital signal itself then we can “easily” filter it out because it’s heterogeneous.

 

Step 2. Keep all the data processing and power supplies, monitors etc. separated and as far from the audio gear as possible. I.e. put all source and computer gear in another room and on another mains power line so the only connection between the source and DAC is by the LAN cable. 

 

I agree that noise problems isn’t exclusive to computer audio the same (make no harm in the first place) is true with a separate CD transport as well.

[Ralf11]

manis, can we add...

 

3. radiated noise (RFI)

 

to separate line noise from 'ambient'

 

also, where in the DAC unit, or where in the DAC chip, is the noise affecting the signal - that might be a useful thing to know...

 

or... where is which type of noise affecting the signal...

[manisandher]

24 minutes ago, Summit said:

 

The noise will not become embedded into the digital signal if the data processing, the power and the whole room would be noise free. Ok? But that’s impossible so the best is to never let any noise geting even near the data or digital signal in the first place.

 

Step 1. Let’s remember that noise are by-products generated from various types of transmissions, power regulations, data and signal processing, PSUs etc etc. If we would make all signal processing with only a noise profile that’s much higher than the digital signal itself then we can “easily” filter it out because it’s heterogeneous.

 

Step 2. Keep all the data processing and power supplies, monitors etc. separated and as far from the audio gear as possible. I.e. put all source and computer gear in another room and on another mains power line so the only connection between the source and DAC is by the LAN cable. 

 

I agree that noise problems isn’t exclusive to computer audio the same (make no harm in the first place) is true with a separate CD transport as well.

 

I don't know enough about the mechanism(s) involved to comment one way or the other. But my experience as a listener suggests that digital audio is anything but trivial to do well.

 

Mani.

[manisandher]

2 minutes ago, Ralf11 said:

3. radiated noise (RFI)

 

to separate line noise from 'ambient'

 

Ambient RFI noise may well have some influence at the d-a conversion stage, but in our case it would have remained constant during the A/B/X, so can't account for the audible changes I heard. Unless I've misunderstood what you meant.

 

2 minutes ago, Ralf11 said:

also, where in the DAC unit, or where in the DAC chip, is the noise affecting the signal - that might be a useful thing to know...

 

Not sure how we'd figure this out.

 

Mani.

[Ralf11]

AFAIK, some of the people making DAC units (not chips) are on this forum - they might be able to investigate where the noise is having an effect

[lmitche]

3 hours ago, manisandher said:

Ambient RFI noise may well have some influence at the d-a conversion stage, but in our case it would have remained constant during the A/B/X, so can't account for the audible changes I heard. Unless I've misunderstood what you meant.

You likely changed the frequency of that noise and it's impact in the DAC with the SFS parameter change.

[fas42]

9 hours ago, manisandher said:

Perhaps the only way to make a DAC truly immune to these sorts of influences is to block the digital signal altogether - if the digital signal can get through, so can noise at the same sort of frequency. In which case, we'd better learn to live with, and perhaps start manipulating to our own advantage, the noise entering the DAC... which I think has been @PeterSt's quest for the last 10 years or so.

 

Mani.

 

That's an unacceptable compromise, to me. Engineering is all about having each part of a system doing its job well enough for the final result to reach a certain standard - and the standard should be, only what was encoded in the recording should be audible.

 

Digital audio is hard, because interference effects can intrude, far too easily - at the moment. Which is a long way from saying it's impossible to having the path immune to such factors ... it just takes a bit of dedicated focus to exorcise all the demons that get in the way of satisfying listening, I've found.

 

To my eyes, a lot of the implementation is less than optimum, in standard designs - just changing the practices here will have major impact ... it's all a learning curve.

[Audiophile Neuroscience]

For the longest time we were assured that bit identical files could not possibly sound different. Jitter and timing issues were dismissed as we were told a decent DAC would buffer the signal and re-clock the timing.Similarly the issue of noise was dismissed as galvanic isolation should fix this and so long as the ones were ones and zeroes were zeroes it really didn't matter. After all bits were/are bits. If you heard differences you were assumed delusional and just didn't really understand how computer science or any science worked. All such claims of hearing differences were said to disappear in a puff of smoke when subjected to blind testing procedures. If a difference was heard then a quantifiable difference in the signal must be measurable, we were told.

 

Mani has provided evidence that challenges many of the above assertions. We wait to see if the observed differences are as yet measurable.

[adamdea]

1 hour ago, Audiophile Neuroscience said:

For the longest time we were assured that bit identical files could not possibly sound different. Jitter and timing issues were dismissed as we were told a decent DAC would buffer the signal and re-clock the timing.Similarly the issue of noise was dismissed as galvanic isolation should fix this and so long as the ones were ones and zeroes were zeroes it really didn't matter. After all bits were/are bits. If you heard differences you were assumed delusional and just didn't really understand how computer science or any science worked. All such claims of hearing differences were said to disappear in a puff of smoke when subjected to blind testing procedures. If a difference was heard then a quantifiable difference in the signal must be measurable, we were told.

 

Mani has provided evidence that challenges many of the above assertions. We wait to see if the observed differences are as yet measurable.

What really matters (or at least 50% of it) is whether it's repeatable with controls to identify whether there are tells unrelated to the audio output; the rest is noise. But for the record, why this "delusional" thing? It has never been the issue and it's just going backwards.

[PeterSt]

14 minutes ago, adamdea said:

But for the record, why this "delusional" thing? It has never been the issue and it's just going backwards.

 

??

[pkane2001]

2 hours ago, Audiophile Neuroscience said:

Jitter and timing issues were dismissed as we were told a decent DAC would buffer the signal and re-clock the timing.Similarly the issue of noise was dismissed as galvanic isolation should fix this

 

Mani has provided evidence that challenges many of the above assertions. 

 

You are implying conclusions that are not justified by the test.

 

1. There was no buffering of data in this case and no reclocking, since the output from the PC went over SPDIF into the DAC. Buffering/reclocking is usually associated with asynchronous protocols, such as isochronous USB.

 

2. I see no evidence of galvanic isolation in Mani's DAC or PC. Please share it if you have it.

 

[Audiophile Neuroscience]

11 minutes ago, adamdea said:

What really matters (or at least 50% of it) is whether it's repeatable with controls to identify whether there are tells unrelated to the audio output; the rest is noise. But for the record, why this "delusional" thing? It has never been the issue and it's just going backwards.

 

Not so much "going backwards" as providing the background underpinning Mani's achievement. I agree, and as already said, a reproducible result would strengthen the ability to reject the null hypothesis.

 

In what way would you "control" the experiment differently and how is the present result just "noise" ?

[Audiophile Neuroscience]

14 minutes ago, pkane2001 said:

 

You are implying conclusions that are not justified by the test.

 

1. There was no buffering of data in this case and no reclocking, since the output from the PC went over SPDIF into the DAC. Buffering/reclocking is usually associated with asynchronous protocols, such as isochronous USB.

 

2. I see no evidence of galvanic isolation in Mani's DAC or PC. Please share it if you have it.

 

 

I was referring to historical reasons provided by others as to why it was supposedly impossible for bit identical files to sound different, not specifically to Mani's setup. The actual reason for the observed difference and its measurement is the subject of further inquiry.

[adamdea]

22 minutes ago, PeterSt said:

 

??

The way the human perceptual system works can lead to sensory experiences which may seem to be purely auditory but which are the result of non-auditory inputs and higher level processing. 

[Audiophile Neuroscience]

46 minutes ago, adamdea said:

 why this "delusional" thing? It has never been the issue and it's just going backwards.

 

31 minutes ago, PeterSt said:

 

??

 

5 minutes ago, adamdea said:

The way the human perceptual system works can lead to sensory experiences which may seem to be purely auditory but which are the result of non-auditory inputs and higher level processing. 

 

so what has multi sensory integration and higher level processing got to do with delusional? Mani scored 9/10 on an auditory test.

[adamdea]

17 minutes ago, Audiophile Neuroscience said:

 

Not so much "going backwards" as providing the background underpinning Mani's achievement. I agree, and as already said, a reproducible result would strengthen the ability to reject the null hypothesis.

 

In what way would you "control" the experiment differently and how is the present result just "noise" ?

Lots of things. One would check the double blinding and whether there are tells in the switching , one might try on different dacs and different software. Lots of things aimed at working out what exactly was being detected. Leaping to conclusions is silly, even of one is parti pris

[pkane2001]

5 minutes ago, Audiophile Neuroscience said:

I was referring to historical reasons provided by others as to why it was supposedly impossible for bit identical files to sound different, not specifically to Mani's setup. 

 

Right. And these reasons are not debunked by Mani's test score and may easily be the explanation for why he heard the differences that he did. Your post seemed to imply that Mani somehow proved these assertions about jitter and galvanic isolation wrong. He didn't.

 

 

[adamdea]

1 minute ago, Audiophile Neuroscience said:

 

 

 

so what has multi sensory integration and higher level processing got to do with delusional?

It's got to do with why the word delusional is  not particularly apt

[Audiophile Neuroscience]

1 minute ago, pkane2001 said:

 

Right. And these reasons are not debunked by Mani's test score and may easily be the explanation for why he heard the differences that he did. Your post seemed to imply that Mani somehow proved these assertions about jitter and galvanic isolation wrong. He didn't.

 

 

 

Mani's test score is evidence that bit identical files can sound different, for whatever reason. It is the assertion that this is impossible to sound different which has been challenged and it logically follows that any assertion that purports to explain why it is impossible, has also been challenged.

[STC]

2 minutes ago, pkane2001 said:

 

Right. And these reasons are not debunked by Mani's test score and may easily be the explanation for why he heard the differences that he did. Your post seemed to imply that Mani somehow proved these assertions about jitter and galvanic isolation wrong. He didn't.

 

 

 

An acceptable DBT to prove that bit-identical files can sound different is by using different bit identical files to prove the claim.

 

A difference heard by changing XXHE only proves that SFS can affect the sound. 

[adamdea]

2 hours ago, Audiophile Neuroscience said:

For the longest time we were assured that bit identical files could not possibly sound different. Jitter and timing issues were dismissed as we were told a decent DAC would buffer the signal and re-clock the timing.Similarly the issue of noise was dismissed as galvanic isolation should fix this and so long as the ones were ones and zeroes were zeroes it really didn't matter. After all bits were/are bits. If you heard differences you were assumed to be experiencing differences which may have been caused by non-auditory inputs or higher level processing. All such claims of hearing differences were said to disappear in a puff of smoke when subjected to blind testing procedures. If a difference was heard then a quantifiable difference in the signal must be measurable, we were told.

 

Mani has provided evidence that challenges many of the above assertions. We wait to see if the observed differences are as yet measurable.

Now that would make more sense.

[PeterSt]

4 minutes ago, STC said:

An acceptable DBT to prove that bit-identical files can sound different is by using different bit identical files to prove the claim.

 

I don't think this is related anywhere. Not explicitly and not implicitly.

 

Edit : maybe I quoted too much out of context. But I don't see the context ...