Blue or red pill?

[adamdea]

3 minutes ago, mansr said:

The problem with this is that no matter how carefully you align the tracks, they'll still be off by a fraction of a sample. This causes a spurious difference that increases with frequency.

I was under the impression that nulling to 80dB or so was about the limit that could be achieved 

[PeterSt]

20 minutes ago, adamdea said:

I was under the impression that nulling to 80dB or so was about the limit that could be achieved

 

And ?

Weren't you going to listen ?

If you leave it to diffmaker all what happens is that Archimago is going to tell you that you make up things. Nothing new of course, but what happens in this thread is new (to many).

[manisandher]

37 minutes ago, PeterSt said:

 

That would not be consistent with 44100 samples per second (also not with 176400, although more close).

The 0.5 seconds would be better.

 

It's a 176.4 kHz rate. I'd say 56.7ms is within the limits of my "50ms or so". Anyway, no harm in going for 0.5s.

 

Mani.

[Ralf11]

5 hours ago, adamdea said:

...

I not disbelieving any results, only the analysis of what they mean. People do that with experiments. 

 

An important point, and the reason why scientific publications (usually) have separate sections for Results and Discussion...

[adamdea]

7 minutes ago, PeterSt said:

 

And ?

Weren't you going to listen ?

If you leave it to diffmaker all what happens is that Archimago is going to tell you that you make up things. Nothing new of course, but what happens in this thread is new (to many).

Yes. See above.

[PeterSt]

1 minute ago, manisandher said:

It's a 176.4 kHz rate. I'd say 56.7ms is within the limits of my "50ms or so".

 

Sure. What I was thinking of was the swapping of channels. And even at 5ms that might (or will ?) be audible. 

OK !

[manisandher]

35 minutes ago, psjug said:

What is the high frequency stuff seen on the analog captures?

 

Probably the 'leaky' filter used in XXHighEnd, which just happens to sound good to my ears. But it's the same filter used for both A and B, so can be eliminated.

 

Mani.

[adamdea]

2 minutes ago, Ralf11 said:

 

An important point, and the reason why scientific publications (usually) have separate sections for Results and Discussion...

Yes. Agreed. Incidentally I don't think that the points I have raised about test protocol are particularly outlandish.

[adamdea]

I would add that I would encourage anyone interested in this thread to have a go at downloading and comparing the analogue captures of the dac output for the A and B software settings. Please post whether you think they sound different (ideally have a go at ABxing them).

[manisandher]

1 hour ago, psjug said:

What is the high frequency stuff seen on the analog captures?

 

1 hour ago, manisandher said:

Probably the 'leaky' filter used in XXHighEnd, which just happens to sound good to my ears.

 

Actually, the minor imaging caused by the filter is pretty innocuous compared to all the other HF stuff going on due to the ADC:

 

 

Mani.

[adamdea]

10 minutes ago, manisandher said:

 

 

Actually, the minor imaging caused by the filter is pretty innocuous compared to all the other HF stuff going on due to the ADC:

 

 

Mani.

Well  it’s lower in absolute level, but also an octave lower in frequency and perhaps in greater danger of creating intermodulation products. 

[testikoff]

A real PITA trying to align the analogue captures 1 & 2, but here are the spectral graphs:

 

- Spectra/delta (frequency range 20...88200Hz; logarithmic scale):

 

- Spectra/delta (frequency range 45000...50000Hz; linear scale):

 

 

- Delta closeup (frequency range 45000...50000Hz; linear scale):

 

Some strange spiking near ~48.5kHz frequency...

[manisandher]

12 minutes ago, testikoff said:

A real PITA trying to align the analogue captures 1 & 2, but here are the spectral graphs:

 

Great! Thanks for doing this.

 

12 minutes ago, testikoff said:

Some strange spiking near ~48.5kHz frequency...

 

Yep, that's the ADC doing something weird, I think.

 

So what are your thoughts on whether there should be any audible differences between the two, based solely on these measurements?

 

Mani.

[pkane2001]

17 minutes ago, testikoff said:

A real PITA trying to align the analogue captures 1 & 2, but here are the spectral graphs:

 

- Spectra/delta (frequency range 20...88200Hz; logarithmic scale):

 

- Delta (frequency range 45000...50000Hz; linear scale):

 

Some strange spiking near ~48.5kHz frequency...

 

So I'm clear: you phase aligned the two analog captures in the time domain, and then subtracted one from the other and then did an FFT plot of the difference?

[testikoff]

Just now, manisandher said:

 

Great! Thanks for doing this.

 

 

Yep, that's the ADC doing something weird, I think.

 

So what are your thoughts on whether there should be any audible differences between the two?

 

Mani.

Not sure... Digital captures 1 & 2 are identical. Analogue captures are very close spectrally (especially in 20...20000Hz audible range), but not quite the same.

[testikoff]

4 minutes ago, pkane2001 said:

 

So I'm clear: you phase aligned the two analog captures in the time domain, and then subtracted one from the other and then did an FFT plot of the difference?

No, just lined up samples the best I could on time axis (almost impossible to do with all the HF noise present), plotted their spectra & then calculated spectral delta.

[manisandher]

2 minutes ago, testikoff said:

Digital captures 1 & 2 are identical.

 

OK, that's the third confirmation we've now got of that.

 

2 minutes ago, testikoff said:

Analogue captures are very close spectrally (especially in 20...20000Hz audible range)...

 

My hearing is only good to 12kHz nowadays.

 

2 minutes ago, testikoff said:

... but not quite the same.

 

Enough of a difference to be audible in your opinion?

 

Mani.

[testikoff]

4 minutes ago, manisandher said:

Enough of a difference to be audible in your opinion?

Not for me with my gear...

[pkane2001]

9 minutes ago, testikoff said:

No, just lined up samples the best I could on time axis (almost impossible to do with all the HF noise present), plotted their spectra & then calculated spectral delta.

 

Ah, thank you, I understand. Not sure if you really need to carefully align samples in the time domain to get the spectrum plot differences, but it shouldn't hurt anything.

 

[manisandher]

33 minutes ago, testikoff said:

- Delta closeup (frequency range 45000...50000Hz; linear scale):

 

Do you have a delta closeup for 20Hz-20kHz?

 

Just now, testikoff said:

Not for me with my gear...

 

Haha...

 

Mani.

[mansr]

44 minutes ago, testikoff said:

Some strange spiking near ~48.5kHz frequency...

Not strange at all. There's a noise spike from the ADC there, and it won't have the same phase relationship with the input signal between the two captures. When the audio is lined up, this noise will be out of phase resulting in a difference like the one seen in your plot.

[testikoff]

17 minutes ago, manisandher said:

 

Do you have a delta closeup for 20Hz-20kHz?

 

 

Haha...

 

Mani.

Here you go:

 

- Delta closeup (frequency range 20...20000Hz; logarithmic scale):

[manisandher]

6 minutes ago, testikoff said:

Here you go:

 

- Delta closeup (frequency range 20...20000Hz; logarithmic scale):

 

Thanks!

 

So, the analogue captures are virtually identical up to 14kHz. My ears are good to 12kHz nowadays. And yet I heard clear differences in the A/B/X.

 

Mani.

[jabbr]

39 minutes ago, manisandher said:

 

So, the analogue captures are virtually identical up to 14kHz. My ears are good to 12kHz nowadays. And yet I heard clear differences in the A/B/X.

 

My impression is that your measurement technique is not capable of demonstrating the difference that your ears hear. ?

[manisandher]

5 minutes ago, jabbr said:

My impression is that your measurement technique is not capable of demonstrating the difference that your ears hear. ?

 

Totally agree. And I'm glad you said "technique" as opposed to equipment.

 

Am I allowed to quote something I posted earlier in this thread? Who's to stop me? 

 

On 2/16/2018 at 11:00 AM, manisandher said:

Can something sound different to a listener if the difference can't be measured (in any way that we currently know of)? Those of us who say "yeah, maybe" are automatically lumped in with the 'audio nutters'. It's frustrating sometimes.

 

Mani.