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Is a modified Offset audible in a .wav track?

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FrantzM

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Annoyed .. Here Steve N. came a made a point about rippers being different ... His claims , his burden of proof .. yet we go around proving his point wrong ... Down the rabbit hole , I say .. Annoyed to no end.. Will unsubscribe to the thread. A first for me :(
 
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No one can prove that all rippers will rip correctly on all CD readers and will be played properly on all devices/software. That is a patently absurd challenge.

The files may look very different because the RIFF format is very flexible (and not so strictly defined) and you can embed a ton of things in them, but what matter is the audio data stream.

I picked up one old CD and did a comparative rip with EAC and WMP. Here is the result.

View attachment 23937

That, in itself, does not prove EAC will not be better in some case. But generally speaking, it the "IT" part of your chain is working fine, there is no need to chase the ghosts of the past.


Bit perfect does not show whether the offsets are identical.
 

March Audio

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Then it's really easy for you to go to another thread and stop posting on this one.

I'm sorry but you need to understand this isnt the same as most other hifi forums. Here you need to justify claims. "I hear a difference" simply won't get you very far, and without supporting evidence derived by controlled methods you are just kidding yourself and wasting people's time.

It's been demonstrated by various methods that there is no difference, no difference in the audio data and no difference in the dac output. So it is very much down to your flawed individual perception, and not the reality of the situation.
 
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SIY

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Bit perfect does not show whether the offsets are identical.
What happens if I delay pressing the play button for 100 milliseconds?

Seriously, put up or shut up. If you have evidence of audibility, present it. If you don’t, then don’t post in a forum dedicated to rationality. The tests of your product already showed that it’s an overpriced solution to a non-problem. This nonsense is clearly aimed at the wrong audience. Remember the famous Thomas Sowell quote about skilled con men.
 

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I have not kept up with this thread. Steve, if there is an audible difference to you between files with different offsets, the starting point of any discussion on this forum would be for you to run an ABX test and show positive results. It is trivial for any of us to guess randomly and produce non-positive outcome with ABX. So not sure why you are asking us to help with the cause.

If you can't or won't run the ABX test, we are done here.

BTW, there is a case where adding zeros changes things: when re-encoding, already lossy encoded files. That forces the audio frames to be different from each pass and reduces distortion substantially for some cases. But in the case that you talk about, I like to see evidence of audibility before we go forward.
 

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If the suggestion really is that the sound of a file can vary, somehow, dependent upon its relative position within some kind of indeterminate packet structure then, arguably, you have a phenomenon that is not testable by conventional means – particularly ABX which relies on having reference audio and the audio under test lined-up accurately to enable the tester to switch between the reference and the audio under test.

We have an alleged phenomenon which, by definition, is not testable if its position has to be manipulated for purposes of the test.

Now call me a cynic but how wonderful it must seem to the audio fairy faction that someone has finally discovered a phenomenon which, by definition, cannot be ABX tested o_O
 

KSTR

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Obviously, one cannot ABX-test the files themselves but the recording of the DAC/system in question playing the two files**), correcting the offset after-the-fact. Devil is in the details, a "reference grade" ADC and subsequent playback is required, the recording should be sample-synchronous or at least with very low clock drift to avoid false cues from A/B-switching discontinuities, a non-trivial difference should show up in the measured residual, and finally the ABX protocol might not always be the best choice for blind testing, ABC/HR and other types might be better suited.
This all is way beyond Steve's capabilties as he has reported to have difficulties even with very simple tasks like inserting a few padding zeros in an audio file....

**) this is the general procedure for any alleged sound differences during playback with bit-identical data.

BTW, anyone can fake a plain text ABX report as generated by foobar2000 or whatever. Posting a result file here is no proof.

As I've said before, I'm more interested in what happens electrically and if I can capture differences in the signal that could be responsible for an audible difference. Proper diff testing is certainly the most powerful method. And if possible I try to use the exact same setup that is used for measurement with no change at all also for blind testing so the correlation has a chance to be valid. It doesn't help if an audible difference is found but the signals aren't captured, and it doesn't help when an electrical difference is found in the lab and no listening test is performed...
 
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Soniclife

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If the suggestion really is that the sound of a file can vary, somehow, dependent upon its relative position within some kind of indeterminate packet structure then, arguably, you have a phenomenon that is not testable by conventional means – particularly ABX which relies on having reference audio and the audio under test lined-up accurately to enable the tester to switch between the reference and the audio under test.
Not true, you can still abx, just not allowing you to switch mid track, you will have to start from the beginning of the track each time. This makes it harder to pass the test, but not impossible to test.
 

Blumlein 88

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If the suggestion really is that the sound of a file can vary, somehow, dependent upon its relative position within some kind of indeterminate packet structure then, arguably, you have a phenomenon that is not testable by conventional means – particularly ABX which relies on having reference audio and the audio under test lined-up accurately to enable the tester to switch between the reference and the audio under test.

We have an alleged phenomenon which, by definition, is not testable if its position has to be manipulated for purposes of the test.

Now call me a cynic but how wonderful it must seem to the audio fairy faction that someone has finally discovered a phenomenon which, by definition, cannot be ABX tested o_O
Sure you could. Duo-trio would work. You have reference, and an identical copy and a non-identical copy. Listen and choose the odd man out. One has 200 more leading zeroes or not. Listen to Reference and A, same or different, listen to Reference and B, same or different.
 

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Not true, you can still abx, just not allowing you to switch mid track
Sure you could
Let's not get too bogged-down in this nonsense – it struck me as vaguely amusing that there might exist a phenomenon which, by definition, is untestable by standard ABX techniques. I could sell you a solution to a problem that, by definition, is audible to the golden-eared but untestable by its very nature. What a business opportunity!
;)
 

amirm

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If the suggestion really is that the sound of a file can vary, somehow, dependent upon its relative position within some kind of indeterminate packet structure then, arguably, you have a phenomenon that is not testable by conventional means – particularly ABX which relies on having reference audio and the audio under test lined-up accurately to enable the tester to switch between the reference and the audio under test.
With typical file ABX tests, there is delay in switching between alternatives anyway so there is no instantaneous switching from one stream to another anyway. In this case, I am assuming the audible difference is also shows up in the first few seconds so one can listen to A, then B and if the latter has an offset that makes it sound different, you would be able to find it.
 
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Empirical Audio

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If the suggestion really is that the sound of a file can vary, somehow, dependent upon its relative position within some kind of indeterminate packet structure then, arguably, you have a phenomenon that is not testable by conventional means – particularly ABX which relies on having reference audio and the audio under test lined-up accurately to enable the tester to switch between the reference and the audio under test.

We have an alleged phenomenon which, by definition, is not testable if its position has to be manipulated for purposes of the test.

Now call me a cynic but how wonderful it must seem to the audio fairy faction that someone has finally discovered a phenomenon which, by definition, cannot be ABX tested o_O

I believe that there is some value in ABX test, however I am actually learning more from the A/B test. The results are proving to be very interesting and with quite a lot of consistency. For instance I want to know more than there is a difference or no difference.

Steve N.
 
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As I've said before, I'm more interested in what happens electrically and if I can capture differences in the signal that could be responsible for an audible difference. Proper diff testing is certainly the most powerful method. And if possible I try to use the exact same setup that is used for measurement with no change at all also for blind testing so the correlation has a chance to be valid. It doesn't help if an audible difference is found but the signals aren't captured, and it doesn't help when an electrical difference is found in the lab and no listening test is performed...

Is your diff test setup different than the listening equipment that would be used? Different software, hardware?
 
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Empirical Audio

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I have not kept up with this thread. Steve, if there is an audible difference to you between files with different offsets, the starting point of any discussion on this forum would be for you to run an ABX test and show positive results. It is trivial for any of us to guess randomly and produce non-positive outcome with ABX. So not sure why you are asking us to help with the cause.

If you can't or won't run the ABX test, we are done here.

I think you must have missed my ABX post. Here are the test files again:

https://www.dropbox.com/sh/bi3zgsyucci2jbc/AABpEF52_62e37AHQMdJ2fL2a?dl=0
 
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Empirical Audio

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That's a collection of files, not an ABX test, not a test result, or a test methodology. The fat lady is hoarse now.

I don't think it's rocket science. You compare the A reference to the A tracks and the B reference to the B tracks and report back which of the files matches the reference.
 
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