Part 2 of the results were published yesterday:
https://archimago.blogspot.com/2020/06/b...-high.html
There is a lot to digest here. Certainly there is some evidence that the levels of distortion used in the test makes a difference, but it is a very long way from a statically clear correlation.
Some interesting trends though, such as those that used headphones performed a lot better than the speaker only group, which perhaps lends some weight to @f1eng 's point about speaker distortion. That said, the "speaker only" group failed to find even the 3% distortion distortion sample "worst", and looking at the of the order of the samples best to worst, it looks almost random to me! (Note, I am not a statistician)
Another interesting result is that the only group that correctly identified the lowest distortion track best, was the group that believed subjective preference did not correlate to THD. Remarkable, although this was a very small group, and it begs the question what their order of subjective preference was. Did they really pick out sample D as having the most THD (which they did) but then stated a preference for this? (this bit not clear)
In addition, there are many cases where even the 3% sample was not found to be "worst". I guess this hints at why some valve amps can sound great when they have appalling on paper measurements.
So interesting results that indicate some correlation with THD. I suspect this will be one article that I will probably re-visit and re-read a couple of times, to try to fully adsorb and think through what is there, but I am starting to think that THD relates to sound quality rather less than I previously thought. Which then begs the question, what does?
EDIT: I stated the above post this morning, got distracted by other things, then finished the above post. The point being I wrote my post before actually reading @thumb5 's slightly earlier post above, although it is nice to see that we seam to have independently reached very similar conclusions. (but yet again, thumb beats me to it .....
)
https://archimago.blogspot.com/2020/06/b...-high.html
There is a lot to digest here. Certainly there is some evidence that the levels of distortion used in the test makes a difference, but it is a very long way from a statically clear correlation.
Some interesting trends though, such as those that used headphones performed a lot better than the speaker only group, which perhaps lends some weight to @f1eng 's point about speaker distortion. That said, the "speaker only" group failed to find even the 3% distortion distortion sample "worst", and looking at the of the order of the samples best to worst, it looks almost random to me! (Note, I am not a statistician)
Another interesting result is that the only group that correctly identified the lowest distortion track best, was the group that believed subjective preference did not correlate to THD. Remarkable, although this was a very small group, and it begs the question what their order of subjective preference was. Did they really pick out sample D as having the most THD (which they did) but then stated a preference for this? (this bit not clear)
In addition, there are many cases where even the 3% sample was not found to be "worst". I guess this hints at why some valve amps can sound great when they have appalling on paper measurements.
So interesting results that indicate some correlation with THD. I suspect this will be one article that I will probably re-visit and re-read a couple of times, to try to fully adsorb and think through what is there, but I am starting to think that THD relates to sound quality rather less than I previously thought. Which then begs the question, what does?
EDIT: I stated the above post this morning, got distracted by other things, then finished the above post. The point being I wrote my post before actually reading @thumb5 's slightly earlier post above, although it is nice to see that we seam to have independently reached very similar conclusions. (but yet again, thumb beats me to it .....
)
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