[stv014]

Quote:

Originally Posted by nicholars /img/forum/go_quote.gif
 
http://www.ethanwiner.com/audiophoolery.html
 
Then it would mean that all dac's of decent quality are beyond perceptable levels of distortion, jitter etc...
 
However it might be the analog stage of the Dacs and other factors giving different dacs different signatures...

 
I think the article also considers the "other factors", so the distortion etc. is the total distortion for the entire device, including any analog stages, power supply, and other parts.

 

[goodvibes]

Quote:

This is an an interesting test and in the REAL world it may show that the Emperor indeed has no clothes.
 
 
HOWEVER   hard-core subjectivists can come up with an "out" -  "Well of course no one could hear the difference all we could hear was the A-to-D artifacts of the E-Mu 0204, which masked the undoubtedly huge differences in the DACs!"
 
I don't think that argument is valid, but "they" will think it is.
 
I'm building an A/B/X  box which will compare 2 level-matched DACs in a blind, computer-controlled random test; I hope to (someday!) have this rig at a Can Jam set up for anyone to come over and take the test controlled by the laptop with results to be collected by the computer and announced on Head-Fi.  Of course, the subjectivists could claim that passing the line-level audio through the rhodium-plated relay contacts negates the test, or that the interconnects I will be using are masking the sound or......  on and on and on.
 
PUTTING THEIR MONEY WHERE THEIR MOUTH IS: Here on Head-Fi I once challenged ANYONE to be able to correctly identify the difference of a Beta 22 amplifier going through  1 meter of silver wire and 1 meter of copper wire in an A/B test; If they are correct in  six or more trials out of ten, I give them $500 of my money and $500 of their money going to me if not.  WHAT A SHOCK  no one replied.
 
All that said, I have my own plans to do an A/B listening test with a couple of DACs that I have, one of my "non scientific" tests - so-called because for reasons of ease and speed I am not going to do a blind A/B comparison at this time. Blind testing will wait until I master the code writing needed to control my relay A/B box from a PC.   (Too many projects, too little time)
 
I have a few DACs because I have a few different rooms with systems, each one needs a DAC....  but so far my impression is that the Musical Fidelity Vdac mk 1  that I have is a little "softer" sounding, maybe even a little "tubey" compared to other DACs I have-  I don't know if this judgement will hold up under A/B  or blind A/B testing; it may just be a prejudice that comes from reading reviews and so on.
 
I suspect that one actual difference that might be heard between DACs is a little roll-off in the treble on some DACs.  44.1k DACs  do differ a bit in flatness of their high frequency response, and that may be fairly easy to hear if you're young enough to have good hearing above 15 kHz.  (Which leaves me out!   hahahah!)

 I no longer hear much beyond 15k and there's almost no content up there. At 58, my built in noise floor has increased as well.

 
There's lots of loop holes here. So what? I believe that the point is to take the test and see if we can find a correlation or hear a difference. A negative in this case wont prove much but so what, have some fun. Everybody's angling ahead of time. Just do it and have a laugh if the results aren't what you expect. I don't think skamp ever meant it as proof of anything and just a fun exercise, perhaps as much for one's psyche as their ears. LOL No one ever seems to take his tests.
 
 I heard differences but after the first few it was unimportant. Low level content seemed to suffer in many samples. I used what I consider MidFi in an easy way to test instead of taking a lot of time for this. It's not that controlled and should be entertaining. If I were to do this for myself, I would do it a bit differently and I'm sure if skamp wanted absolutes frome this he would have as well.
 
It takes less than 15 min. to download and listen. Take Nike's advice, just do it.

 

[skamp]

As always with such tests, you can't prove that there aren't any audible differences. You can only prove that there are, so this is an opportunity for audiophiles, even if they don't take it.

 

[eucariote]

Quote:

As always with such tests, you can't prove that there aren't any audible differences. You can only prove that there are, so this is an opportunity for audiophiles, even if they don't take it.

 
With hypothesis testing and statistics, you could demonstrate either outcome (see example 2).  This is the standard method for proving and disproving scientific hypotheses from empirical data.  You dismissed it earlier, but I'll post it again:
 
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Very cool!  I think that a blind dac comparison is sorely needed.  For the sake of analysis, I'd suggest that you ask people to give you results in a way that pairwise comparisons would be possible, like rankings or a>b comparisons.  That way you could run statistics against a binomial distribution of independent superior/inferior comparisons against the null hypothesis that each dac would be chosen with a 50% probability.  You could then use standard criteria for accepting or rejecting the null hypothesis, the latter in cases where people's choices are not random.

 
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Identifying one piece of gear among 7 samples is more interesting than the 50/50 chance of a set of only two samples. Identifying TWO pieces of gear is all the more interesting.

 
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This is how you would set up a test to answer the question: can people reliably hear a difference between one dac and another?  This first has to be established before venturing to answer less parsimonious/more derivative questions of picking one out from a crowd, etc.  I don't know if even this basic discriminative ability has even been demonstrated, notwithstanding tens of thousands of posts at head-fi that that swear it is possible.

 
I'd be happy to run the statistics for you when all the data is in.

 

[skamp]

Sure. I'll disclose which is which on feb. 28, then you can knock yourself out

 

[eucariote]

Will do.  

  It would take a good number of samples (~10-15 per comparison) so let's hope that lots of people submit their guesses. 

 

[NA Blur]

If the top end is rolled off in on any of the tracks my hearing did not detect it.  It would also be nice to have a 30s clip of silence from each DAC to determine if the noise floor is low or not on some of the units.  This goes for signal to noise ration too, but I heard little to no issues with that on any of the tracks.
 
It has been shown that if you do a rip with a hi-end DAC or low-end the 1's and 0'1 remain intact.  The primary differences were signal to noise ratio and of course jitter, but the rips were identical.

 

[stv014]

Quote:

If the top end is rolled off in on any of the tracks my hearing did not detect it.  It would also be nice to have a 30s click of silence from each DAC to determine if the noise floor is low or not on some of the units.  This goes for signal to noise ration too, but I heard little to issues with that on any of the tracks.

 
There is a file here that contains the difference between the sound recorded from a RealTek ALC887 codec and the original sample (equalized to have the same frequency response). It is not perfect because there is some drift over time that also makes the original sound audible at a reduced level, but nevertheless the noise can be heard well. Low quality DACs often have high noise modulation, that is, their noise floor increases with the signal, and they may also produce other artifacts. Note however that this difference file is amplified by 40 dB, so the noise and artifacts are not that loud in reality; the original and recorded sound are also available in the same thread, so you can check with an ABX comparator if you actually hear a difference.

 

[skamp]

It would also be nice to have a 30s click of silence from each DAC to determine if the noise floor is low or not on some of the units.  This goes for signal to noise ration too, but I heard little to issues with that on any of the tracks.

You will find those values in my unloaded RMAA measurements.

 

[Takeanidea]

Hi skamp well I think that was fun. It all sounded a bit harsh to me . I listened to them all for about 20 mins . There were some I liked more than others. The drum break sound was the thing that had me most on edge.
I will give it another listen tomorrow and pm my findings to you. I might be thick but when you mean the original and 6 copies...how have you recorded them?

 

[wakibaki]

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...it would mean that all dac's of decent quality are beyond perceptable levels of distortion, jitter etc...

 
This is the view held by Peter Aczel, editor of 'The Audio Critic'.
 
http://www.theaudiocritic.com/
 
If you haven't seen The Audio Critic, you might enjoy reading a few of the back issues.
 
My own view is that while there might be tiny perceptible differences between DACs, they are truly tiny, and any time spent trying to hear them is just time that could be better spent listening to music, and moreover that anyone who focuses on this as a serious issue cannot be considered to have a genuine interest in or appreciation of music.
 
Not that I'm running down this test, considering the amount of BS the general public have heaped upon them, it's entirely reasonable that people should try to debunk some of it, I just think that people who claim that they get tremendous added pleasure when changing from one piece of equipment to another don't actually get the normal kind of pleasure that music usually gives.
 
w

 

[Takeanidea]

Quote:

 
This is the view held by Peter Aczel, editor of 'The Audio Critic'.
 
http://www.theaudiocritic.com/
 
If you haven't seen The Audio Critic, you might enjoy reading a few of the back issues.
 
My own view is that while there might be tiny perceptible differences between DACs, they are truly tiny, and any time spent trying to hear them is just time that could be better spent listening to music, and moreover that anyone who focuses on this as a serious issue cannot be considered to have a genuine interest in or appreciation of music.
 
Not that I'm running down this test, considering the amount of BS the general public have heaped upon them, it's entirely reasonable that people should try to debunk some of it, I just think that people who claim that they get tremendous added pleasure when changing from one piece of equipment to another don't actually get the normal kind of pleasure that music usually gives.
 
w

I have thought long and hard about these claims, and have listened long and hard to these samples. The Dacs that have been put on test are hardly high end stuff are they? Yet there is a difference between the 30 second tracks. Whether a $5 track sounds better at that moment to what my ears prefer ; what does it prove?
There are differences between all of these tracks, that proves one thing , not one Dac this skamp has is identical.
What is making them different? Are the differences easy to spot when we're bombarded with 7 30 second snippets of really loud music played immediately one after the other? Nope. But after months of using kit , decent kit, you learn the intracancies of it that don't come out in 30 seconds.
This site is all about sharing our experiences of how we enjoy listening to music through headphones.
Not all hi fi sounds the same . The research out there from the skeptics seems to suggest there are differences between analogue components but modern digital components have no difference irrespective of cost. Analogue components in Dacs are the output stages, then you have the headphone outs of the amps then finally the headphones , which I read cannot compare to even the cheapest digital components for the distortion and freqency response they are capable of.
So there's still a lot of scope for differences in sound quality and might come to explain why I get a different sound from my BM Dac headphone out as opposed to my Young through my Novo or my M-Dac through my Fidelity and all the headphones I use.
Enough putting off the moment of truth...time to plough through this blind test one last time

 

[stv014]

I somehow suspect you either did not hear a difference, or did not even bother using an ABX comparator

 

[miceblue]

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I believe the test incorporate too many samples and is too complex to be useful.

I've come across the claim that some gear that I own has a very specific "sound signature" and is easily recognizable. Identifying one piece of gear among 7 samples is more interesting than the 50/50 chance of a set of only two samples. Identifying TWO pieces of gear is all the more interesting.
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when testing  blind in controlled conditions I was incapable to tell them apart.

That's not surprising. Unfortunately, I doubt that any of the people who claim to hear obvious differences will take this test, much less post their findings. Which wouldn't be surprising either.

I'm guessing that's the "Current iPod Classic vs Clip+" thread? I kind of left that thread after having people argue over nothing. XD
I'm interested in this test nonetheless as I was one of those people who said the Video 5G sounded warmer than the Clip Zip.

 

[Hi Rez]

Interesting thread.  The samples all sound pretty similar to me. I am curious as to how the "original" sample was created.