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manisandher

Blue or red pill?

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Edit April 18th 2018

 

Here are my final thoughts on this thread:

 

A) We know for sure that :

  1. the two playback means, A and B, were bit-identical
  2. A and B were audibly different (to a 99% probability), once they passed through a DAC

 

B) With no evidence to the contrary, it's reasonable to assume that:

  1. the DAC received bit-identical data in both cases
  2. the A/B/X was conducted in a trustworthy manner

 

C) We can speculate that:

  1. the audible differences were caused by different 'jitter signatures' in the DAC during the D-to-A process
  2. the effect of these jitter signatures on the sound is difficult to capture with a modern, well-respected ADC

 

My key take-away from this experience is that the 'red pill' is way more bitter than I could ever have imagined, for those who are entrenched in their beliefs. No amount of evidence contrary to their beliefs seems to help. If you score a 99% probability in a well-executed A/B/X, then "the A/B/X must have been at fault". Etc, etc. I think it's a shame...

 

**********************************************************************************************************

 

Edit April 16th 2018.

 

For anyone who is interested in doing some analysis of the digital (taken in real-time during the A/B/X) and analogue (taken immediately after A/B/X) captures, in the following link you'll find 4 files:

 

1. digital capture _ A

2. digital capture _ B

3. analogue capture _ A

4. analogue capture _ B

 

https://drive.google.com/open?id=10SD3SSdXV-P0ZFEte31NSFXeO0UhBYBi

 

Enjoy!

 

Mani.

 

***********************************************************************************************************

 

Invitation for @mansr

 

Come up to my place (Leamington Spa, UK). I'll pay for your fuel or train ticket.

 

Refuse (blue pill) and continue believing whatever you want to believe.

 

Accept (red pill) and I'll show you how deep the digital audio rabbit hole goes.

 

Remember: all I'm offering is the truth.

 

***********************************************************************************************************

 

Edit March 26th 2018.

 

Results of A/B/X test conducted during Mansr's visit to my place:

 

During the A/B/X test, I was noting my results in a notebook. Meanwhile, Mans was using a random generator on his phone, and also noting the order of playback on his phone. Once we had done 10 A/B/Xs, we compared the two lists. I ticked all those correct. Here's the page from my notebook:

 

5ab9551f6ad9a_A_B_Xresults.thumb.jpg.d776595cf99df00b535d7f411e0992af.jpg

 

Yep, that's 9/10! There's a 1% probability of achieving this through guessing alone.

 

The 6th result is interesting. I had initially written '2?'. But when I listened to the 7th sample, it was clear that the 6th must have been '1', so I crossed out the '?' and wrote '1' over the '2'.

 

************************************************************************************************************

 

Edit April 11th 2018.

 

A 10kHz sine tone was captured at the analogue outputs of the DAC, in configuration '1' (SFS=0.1) and configuration '2' (SFS=200). The configurations '1' and '2' were measured to be bit-identical. Mans found a small difference in the FFTs of these captures, due to a small difference in jitter between them:

 

mani-10k-fft-16m.thumb.png.39c7d98fc8113ccf74471c2c07bf73b1.png

This suggests that there are indeed measurable differences in bit-identical playback at the output of the DAC. A couple of points:

 

1. The plot shows that the test setup was of high quality. The DAC cannot be blamed for being particularly vulnerable to the effects of jitter.

 

2. The plot suggests that the differences between '1' and '2' are tiny. It would be truly amazing if the human ear were able to discern such differences. And yet the A/B/X suggests exactly that!

 

************************************************************************************************************

Edit 2 April 16th 2018

 

@testikoff has just undertaken the painstaking task of comparing the two analogue captures:

 

AC12_d_log.jpg

 

It seems that they are virtually identical below 14kHz. My ears are only good to 12kHz or so nowadays... and yet I heard clear differences in the A/B/X.

 

Mani.

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6 minutes ago, manisandher said:

Invitation for @mansr

 

Come up to my place (Leamington Spa, UK). I'll pay for your fuel or train ticket.

 

Refuse (blue pill) and continue believing whatever you want to believe.

 

Accept (red pill) and I'll show you how deep the digital audio rabbit hole goes.

 

Remember: all I'm offering is the truth.

 

Mani.

 

 That is the only way to make most E.E's change their minds in some areas.. A DIRECT Demonstration.

It took a direct demonstration to change the minds of 2 Sydney Au. E.E.s that I know personally.

 

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22 minutes ago, manisandher said:

Accept (red pill) and I'll show you how deep the digital audio rabbit hole goes.

 

Remember: all I'm offering is the truth.

 

I hope for your sake this rabbit hole doesn't go as far as you (illegally) capturing the streamed bits from TIDAL, just so you can prove that they're exactly the same as the bits from the same named album track files stored on your NAS. Otherwise, how can you prove they're exactly the same bits?

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3 minutes 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.

 

Mani.

Ryanair flies from Bournemouth which is close to Southampton.

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What, you know someone on the inside who can reliably state the exact provenance of the redbook audio files supplied by TIDAL's online servers (which by some amazing coincidence happen to exactly match that used to create the CDs you ripped) and can also guarantee that the TIDAL files haven't been tinkered in any way?

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I'd start by simply copying a track from my NAS to a local folder in the audio PC and playing the identical files back from their respective locations. That'll break his belief system right there. We can then explore other areas if he's interested.

 

Mani.

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8 minutes ago, mansr said:

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

 

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

 

Mani.

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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.

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13 minutes ago, mansr said:

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

 

9 minutes ago, mansr said:

I'll bring some recording equipment.

 

8 minutes ago, kumakuma said:

 

That might actually be interesting...

 

 

ElatedGloriousEagle-size_restricted.gif

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22 minutes ago, mansr said:

I'll bring some recording equipment.

 

 It's highly unlikely that any of the differences that may be heard in a direct demo, will still remain after re-recording,

although they may remain to some extent if burned to a high quality CD-R from their existing locations.

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The suggestion was recording the audio related conversations that may take place and whatever discoveries might come about.  If I understood his intent.  

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11 minutes ago, rando said:

The suggestion was recording the audio related conversations that may take place and whatever discoveries might come about.

 

I really don't think that's necessary.

 

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

 

Mani.

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4 minutes ago, manisandher said:

 

I really don't think that's necessary.

 

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

 

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

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2 hours ago, sandyk said:

 

 That is the only way to make most E.E's change their minds in some areas.. A DIRECT Demonstration.

It took a direct demonstration to change the minds of 2 Sydney Au. E.E.s that I know personally.

 

 

Interesting Alex. I've offered to setup a direct demonstration for you but you have blanket refused any and all offerings. 

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2 minutes ago, kumakuma said:

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

 

I don't think he's intending to use a cassette recorder with Dolby C.

 

Mani.

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