If you need to adjust the output every time when you switch the DAC the ABX you do would likely to exceed the short term sound memory.
It's easy to match 0.1dB digitally just use Element or similar software to route the output to different DAC. And it can compensate the delay between DACs also output simultaneously.
It's easy to match 0.1dB digitally just use Element or similar software to route the output to different DAC. And it can compensate the delay between DACs also output simultaneously.
Good - so from now on, all your statements about SQ will be based on you using the ITU protocol and we can ignore all historical statements!?
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As long as the participants in any test know what they are listening to, or more impotant, are fed with info they will be listening to different devices, the test will be flawed. So we have to be bit more creative.
In my view for starters the real thing should be a sighted test, where in different cases, preferably including some fancy brands, three sets of the exact the same DAC's are listened to, levels carefully calibrated and forming part of the same chain. I am positive the Usual Suspects, a.k.a. the Golden Ears, will claim to observe differences. Once facing the test setup, they will come up will all sorts of reasons why the test was fundamentally flawed. And yes, I know this test doesnot tell us anything about audible differences between DAC' s.
Test nr. 2 is where the real fun begins: swapping housings with different DAC s: the expensive stuff goes in to the cheap housing and vice versa. As long as there are no consistent, repeatable 100% scores, the claimed dfferences are imaginary in my book.
In my view for starters the real thing should be a sighted test, where in different cases, preferably including some fancy brands, three sets of the exact the same DAC's are listened to, levels carefully calibrated and forming part of the same chain. I am positive the Usual Suspects, a.k.a. the Golden Ears, will claim to observe differences. Once facing the test setup, they will come up will all sorts of reasons why the test was fundamentally flawed. And yes, I know this test doesnot tell us anything about audible differences between DAC' s.
Test nr. 2 is where the real fun begins: swapping housings with different DAC s: the expensive stuff goes in to the cheap housing and vice versa. As long as there are no consistent, repeatable 100% scores, the claimed dfferences are imaginary in my book.
I posted this about Deltawave earlier in the thread:
https://www.diyaudio.com/community/...if-they-both-measure-well.418579/post-7814130
While ADC does have an impact on Deltawave analysis in that test nobody was even able to reliably identify original from the ADC recordings in ABx. Although admittedly not many dared to report their ABx results.
Just drive one speaker with both amplifiers and same signal and level simultaneously and listen. If you hear something they are different, if you hear nothing, they are identical. This is something called a phantom channel in the early sixties. It was supposed to offer you a realistic sound experience.
That only works for large differences, not for subtle ones where one may not hear the difference on poor recordings, or if one has a bad day or whatever.
For example, from the data on a pre-echo experiment in the attachment, I'm inclined to believe that participant #2 could hear the difference, except on the one recording that he found to be of inferior quality (he complained about it before the results were made public) and only when he was in his normal state of consciousness. Interestingly, he was the only participant who wasn't sure that he heard any difference at all.
The paper concludes that the listener must be in a normal state of consciousness. What does a normal state of consciousness mean and for whom. Oh boy what is next, a test for normal state of consciousness.
Participant #2 didn't want me to write stoned, because at the time of writing, marijuana was still illegal in his country. Hence "altered state of consciousness" 😉
Nevertheless it's important as something that's louder will allow more detail to be audible.
I'd love to see some ABx results of those with very revealing systems who claim to hear differences between the original and the DAC->ADC recording.
A reminder of some of the claims:
I think that would go a long way in convincing skeptics of the listener's ability.
Michael
The louder one will be preferred, of course. But if it comes out in ABX testing it means people are discriminating one is louder than the other without knowing that's what they are doing. That's because ABX is inherently only for discrimination testing.
For other types of discrimination testing, it depends on what the actual difference is that is being discriminated. Some audible effects are influenced by volume level way more than other things. The example I gave previously had to do with horn player vibrato and whether there was only frequency modulation, or if there was also amplitude modulation too. That particular discrimination task in pretty insensitive to volume level.
Also, if you record the two dacs then try to listen to the two files, if you are using a dac that does not reproduce vibrato amplitude modulation well, then you will probably never hear the difference. Comparisons in DeltaWave may be exactly the same because the average level of vibrato volume level is the same for both dacs (its that one is modulated around the average, and the other isn't). That average is what you see in an FFT analysis. (note: modulation implies sidebands, but its the phase of the sidebands that matters, not just their amplitudes)
The point is that there is no one-size-fits-all solution to trying to figure out if two dacs sound the same or different. That includes whether SINAD is good enough.
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Both time domain and frequency domain analysis are available in Deltawave so difference would be seen provided the recordings have it.
When a whole jazz band is playing at the same time, good luck picking out the phase of two small sidebands.
Moreover, when I talked about the volume modulation before I mentioned it could happen with the same dac if its clocks where substituted. IOW, it could be a jitter effect that is obscuring the volume modulation. Its not clear to me if DeltaWave has any way of detecting that.
Moreover, when I talked about the volume modulation before I mentioned it could happen with the same dac if its clocks where substituted. IOW, it could be a jitter effect that is obscuring the volume modulation. Its not clear to me if DeltaWave has any way of detecting that.
Given the findings of Audio Scene Analysis, I'm not so sure about that. The brain can pick out things in a complicated audio scene that would be challenging to measure. There could be thousands of frequencies, some big, and some small, to track the phase of. Also because there is pitch vibrato too, the frequencies that in the volume vibrato are constantly changing, so phase tracking would need to follow those frequency changes across bins.
More likely would be that DeltaWave gives the phase of each bin averaged over the length of the song. A brief horn vibrato spanning across bins might have a vanishingly small affect on the average phase for each bin.
More likely would be that DeltaWave gives the phase of each bin averaged over the length of the song. A brief horn vibrato spanning across bins might have a vanishingly small affect on the average phase for each bin.
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No need to speculate. Create 2 recordings that have such difference which you can hear. Then we can analyze the recordings with Deltawave.
That could be a good test alright. Have to think about it. I would want to use frequencies that are already used a lot in the music. Maybe change the brush pattern on a snare drum slightly for one beat in the song. Probably I would need all the tracks for a busy recording, so I could mess with just one of them a little bit.
Thinking about what if I swapped the position of two snare brush patterns so they occur at different points in the song, but the song is on average the same.
To make it fair, the DeltaWave operator should not listen to the files so as to be able to focus in on spots that do sound different, only use the FFT analysis to see if it detects the difference unaided.
Just remembered I have some files made by PMA of different opamps. Those are the files I sorted for distortion. I could put them in my dropbox if anyone wants to play with them.
Thinking about what if I swapped the position of two snare brush patterns so they occur at different points in the song, but the song is on average the same.
To make it fair, the DeltaWave operator should not listen to the files so as to be able to focus in on spots that do sound different, only use the FFT analysis to see if it detects the difference unaided.
Just remembered I have some files made by PMA of different opamps. Those are the files I sorted for distortion. I could put them in my dropbox if anyone wants to play with them.
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The same applies to the claim of different sound. That should be verified by someone who does not know about the difference.
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