A proper blind test will tell you for certain whether a DAC or other device is audibly transparent. No measuring needed!
I have to admit I don't think peering in very deeply has much value. I think with FFT/IFT it's paramount to remember the inherent time-frequency tradeoff with various widowing sizes and types. And that they all end up being a snapshot averaged over some time period that has to mathematically describe the signal as if it were steady state. Which is seldom, if ever, the case.
I don't think it pays to assume any one windowing choice is the correct one, so if follows logically not to get too serious with any of them. I think trying to chose the window size and type wisely for the measurement's intended purpose, is about the best can be done.
IIUC, the files are the same in the frequency domain spectral view (within the limits of 16-bit dither), as they were synthesized by MATLAB scripts (which were vetted by 3rd parties). Most likely any differences in measurements are artifacts of dither differences and or of FFT calculation artifacts.
Of course, the time domain is a very different situation. In the time domain, phase of frequencies can matter a lot. In a frequency domain spectral view plot, phase information has been discarded.
Moreover, phase rotation is a well known method of amplitude modulation or frequency modulation. IOW, it is well known that only changing the phase of certain frequency components will change the modulation type.
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There you go. None of them are audibly transparent!
More seriously, today's professional perceptual scientists know how complicated it is to do blind testing well. EE's with who think its all a matter of common sense have fooled many people into thinking they can't hear what they actually can hear. Its a very unfortunate situation.
More information in another thread:
https://www.diyaudio.com/community/...ble-difference-whatsoever.314762/post-8039411
https://www.diyaudio.com/community/...ble-difference-whatsoever.314762/post-8039416
https://www.diyaudio.com/community/...ble-difference-whatsoever.314762/post-8039399
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Look at the wave forms! One stays at the same level and the other varies. So again they do not measure the same.
LOL, except you haven't done the tests! You're just making claims with nothing to back then up. Of course some devices are clean enough to not damage the sound audibly. This has been proved again and again, even going back decades to 1980s DACs:
http://www.bostonaudiosociety.org/bas_speaker/abx_testing2.htm
Blind tests are not easy to do correctly:
https://www.prosoundweb.com/discerning-differences-how-to-conduct-proper-useful-listening-tests/
In the time domain or a frequency domain spectral view? You have to be specific.
Actually, I have done more than you know about. You appear to be jumping to conclusions again.
Based on your posts to this thread so far, I won't believe it until I witness you do a blind test in person. 😗
Where are you located? I am in Auburn, CA. Since I have ultra low distortion Sound Lab electrostatics this is where I think any serious listening tests would have to be done. You would be welcome to bring any dac you like for comparison. We can find a mutually agreeable disinterested 3rd party to do the blind device swapping.
I'm in Connecticut, but at age 76 my traveling days are over. I hate airports! So I won't be coming out there. But it doesn't have to be a DAC that is tested. You said "none of them" (DACs or other devices) are transparent, so the tests could be a unity gain preamp inserted into the signal path, or anything else with active electronics. But let's stick with DACs for now. I'm surprised you actually believe that your hearing is so good that you can identify artifacts more than 100 dB below the music while the music plays. That's quite a claim!
I have several "blind tests" on my web site that you could do in the comfort of your home with your own loudspeakers. Then you'll email me your choices and I'll tell you if you're right or not. If you're up for that, this first A/D/A test asks you to identify an original recording, then an A/D/A loop-back of one generation, then five generations, then ten generations. Your mission is to identify the files in order of degradation.
https://ethanwiner.com/loop-back.htm
This next test asks you to identify a live music source recorded simultaneously through three converters ranging in price from a $25 SoundBlaster X-Fi sound card through to a $2,000 Lavry Blue converter. You have to pick which of the three files was recorded through which converter:
https://ethanwiner.com/converters.html
This last test has you identify two 24/96 hi-res sources with copies reduced to 16/44. You haven't claimed that you can identify hi-res versus CD quality, so this may not be a relevant test for you.
https://ethanwiner.com/hd-audio.htm
I have several "blind tests" on my web site that you could do in the comfort of your home with your own loudspeakers. Then you'll email me your choices and I'll tell you if you're right or not. If you're up for that, this first A/D/A test asks you to identify an original recording, then an A/D/A loop-back of one generation, then five generations, then ten generations. Your mission is to identify the files in order of degradation.
https://ethanwiner.com/loop-back.htm
This next test asks you to identify a live music source recorded simultaneously through three converters ranging in price from a $25 SoundBlaster X-Fi sound card through to a $2,000 Lavry Blue converter. You have to pick which of the three files was recorded through which converter:
https://ethanwiner.com/converters.html
This last test has you identify two 24/96 hi-res sources with copies reduced to 16/44. You haven't claimed that you can identify hi-res versus CD quality, so this may not be a relevant test for you.
https://ethanwiner.com/hd-audio.htm
Ah, but that's not my claim. Where I will find differences in sound will probably be more like at -60dB to -90dB, and or in localization precision. The differences won't be in terms of measured nonlinear distortion nor of fixed noise floor.
As I said before, the things we typically measure tend to get fixed. Its the things that we don't usually or don't ever measure which are the things that still need fixing.
Nope. Don't trust your ability to produce valid blind tests. Maybe you can or maybe you can't, but its not scientifically proven you can. After all, I have seen your paper on isolators, and read your arguments with @gedlee. I have good reasons to have doubts.
Why would we need to do that? As I see it, it would be only of we wanted to cheat... like .mp3 etc. But we don't - so if in=out , we are good - no?
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for me it is, it's others that claim it's not. You can predict how people will hear it, but you can make sure the signal is not distorted in any way. That is the classic definition of hi(delity). All deviations of that (and i like a few) are personal preferences.
OK, I'll argue that we don't need to know anything abut hearing in order to recreate a waveform at a certain place in space - e.g. at just outside an ear.
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LOL, I'll take that as, "I make many claims about what I can hear, but not when the testing is blind."
Those web pages are not "designed tests" that you can fault or criticize, as much as you may try. Either you can identify the file differences or you can't. I assure you there is no fakery in any of those tests. Hundreds of people have taken these tests and emailed me their choices. The files are exactly as stated.
Ethan, how did you produce the files, and how did you select the material or test signals in the file? What procedures did you use, and how did you verify the results? If I understand those kinds of things then maybe I will agree with you, but I may have some more questions before we get to agreement.
I do know very well if you recorded test files with and without isolators that it would not constitute good science to test someone on the difference. You had no idea what audible differences there might be with isolators in a different situation and including effects of a stereo reproduction system. Now, you might not make the same mistakes with your other efforts, but you still may have made some other mistakes or poor choices that bias the outcome to your preexisting beliefs. At this point I have no way of knowing.
I do know very well if you recorded test files with and without isolators that it would not constitute good science to test someone on the difference. You had no idea what audible differences there might be with isolators in a different situation and including effects of a stereo reproduction system. Now, you might not make the same mistakes with your other efforts, but you still may have made some other mistakes or poor choices that bias the outcome to your preexisting beliefs. At this point I have no way of knowing.
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LOL, so you didn't even look at any of those test pages I linked. 😒 None of them are about speaker isolation, and all of them explain clearly how the files were created. The Converters page even links to a video showing the recording session with more details.
Look Mark, I'm glad to participate in this discussion, but if you won't even consider what I say we're both just wasting our time. So please find a few spare minutes to look at those three test pages, then play the files and tell me what you hear. Deal?
Look Mark, I'm glad to participate in this discussion, but if you won't even consider what I say we're both just wasting our time. So please find a few spare minutes to look at those three test pages, then play the files and tell me what you hear. Deal?
Did you read the paper I posted on measuring phase noise and amplitude noise in DACs? Did you read the perceptual science book excerpt I linked to explaining problems with ABX for assessing differences between sounds? If so, did you understand it and revise your beliefs about ABX accordingly?
My guess would be you ignored most it. But, maybe I'm wrong?
Yet, I am supposed to persuaded by your non-scientific goading to do what you want me to do?
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None of those have anything to do with speaker isolation. What you did is called a red herring logical fallacy, when you try to redirect the conversation to a different topic. I did click the link you posted to gedlee.com, but my anti-virus program said the site isn't safe because it contains links to dangerous pages. I actually planned to back up my second PC (image backup), then use that PC to visit gedlee.com. I didn't get around to that yet, and we seem to have moved on anyway.
But the pages I linked are exactly on point. You claim to be able to hear stuff 60-90 dB below the music, and my pages test exactly such a claim. If you link to web pages that support your argument that speaker isolation makes an audible difference, I'll be glad to look at them.
But the pages I linked are exactly on point. You claim to be able to hear stuff 60-90 dB below the music, and my pages test exactly such a claim. If you link to web pages that support your argument that speaker isolation makes an audible difference, I'll be glad to look at them.