B
Bobro
New member
ff123 said:Well, I just compared file1 with file2 using Cool Edit. I trimmed the beginning and end of the files to time align them with each other, then I mix pasted and inverted one file into the other. The resulting difference file looks like the picture below
The differences are plus or minus 1 or 2 bits. The last second or so shows large differences, I'd guess because Ethan applied a fade out.
Presumably, the differences would have been only plus or minus 1 bit if rounding had been used instead of truncation for file 2.
The last second is of some concern because the differences here are more than just the difference between dither and truncation at 16 bits.
I don't believe Bobro's results are invalidated since he writes that he made his comparisons based on the first few seconds of the files and not the end.
ff123
Hehe! I just couldn't listen all the way through the files each time, it was tedious enough as it was.
There's a "droop" in the timbre in the fadeout of File 1, too. I don't know if Ethan still has my emails, but I wrote to him after submitting my reaction to the test saying that we had been doing just such blind tests. He said, great, but mentioned the danger of blind tests, which is imagining differences that aren't there. That is true and got me to wondering if I had imagined things and only been extremely lucky saying "that's File 1, that's 3" and so on to my wife. So I inverted files and lined them up on the sample level.
I did this with 1,2 and 3, not bothering with 4 and 5 because they were too obvious.
As I wrote to Ethan, the "ghost" of the difference was very obvious in the tails, but since that involves the variable of a fadeout, I've pretty much ignored the fadeouts in these tests.
Only 1 and 2 came close to cancelling each other out, but as I wrote to Ethan, you can hear a high fuzzy sound when listening to 1 and 2 "cancelling". He said, that's because one of them has dither. I then realized that I'd ordered the files incorrectly in my guesses, but wasn't concerned because having heard the differences I was prepared to learn how to equate them with the technical differences.
Then Ethan implied on another forum that incorrectly ordering the files according to their technical identity was the same as not hearing the differences between them and that made me very angry.
This is the reason why the ABX test is so cool. There isn't a second level of testing the correlation between what you hear and your technical understanding of what it's called, it's a pure test of hearing differences. Well in spite of all I've read I'm still not sure about things like the difference between truncation and rounding. There was a good explaination on another forum about dithering and I think I finally understand how dithering depths can be fractions, and why you get that clearly audible itchy wooly blanket when you set very deep dithering depths for example.
-Bobro
