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In Reply to: RE: May I enquire why you persist wasting time? posted by Tony Lauck on April 27, 2015 at 12:56:29
Tony,
> It's even more complicated. There are at least three filters
> involved:
While that is true, two of them are fixed. The third may be anything though, from Non-OS via Craven Apodising minimum phase all the way to a standard "not quite brickwall" type.
> This is correct, however this interaction is at the 176.4 sampling
> rate and above.
Not quite. Look at the time domain and you find components much lower.
> Doing critical listening is not a waste of time.
I never said it was.
But if you desire to answer a given question with such test, you must construct the test in such a fashion that it answers this question precisely and you must exclude the possibilities of other interactions giving false positives/negatives.
The test here does not meet these criteria. As such it is a waste of time, just like 95% of those the ABX crowd usually inflicts upon us (I actually did a meta analysis of all published ABX Null results I could find - this suggested with substantial statistical significance that in the whole "meta-analysed" dataset of "null results" reliably detectable differences were present, just the dataset used and the conditions set were adverse to detecting them).
Ciao T
At 20 bits, you are on the verge of dynamic range covering fly-farts-at-20-feet to untolerable pain. Really, what more could we need?
Follow Ups:
As to those DAC filters. The A and B recordings are heavily apodized, since they were the result of upsampling four times. As a result, all good linear phase DAC filters are likely to produce similar results on any given file, i.e. the choice of these filters won't matter.
As a demonstration, I took the Piano A file and upsampled two different ways to 352/32fp using iZotope RX4. Both filters used pre-ringing 1.0 (linear phase) and filter-offset 1.0 (half band). The difference was in the filter steepness. One filter had steepness 32 and the other steepness 1020. (The later filter has a much longer impulse response.)
After generating the two upsampled files I created a difference file by mixing the two out of phase. The largest sample in this difference file was at -144 dBfs, which happens to be the level of roundoff error with 32 bit floating point files. Not much happening in the time domain.
On casual listening all three music files sounded the same to me and the difference file sounded completely silent. I tried boosting the difference file by 120dB (!). It was still inaudible and this surprised me. A spectrum plot of the boosted difference file showed that there was a peak of -65 dBfs at 88.4 kHz, which corresponds to a difference at -185dBfs in the unboosted difference file. There were also time variance in the background level that appeared to be correlated to the loudness of the original piano playing, but the boosted difference file had this time varying noise at even lower levels. (I would guess this has to do with the use of 32 bit floating point to represent the resampled files.)
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
As such it is a waste of time, just like 95% of those the ABX crowd usually inflicts upon us
Quite - but what tempts you to exempt the other five per cent? I've yet to see an audio-related "ABX" test that would pass muster in a school-level psychology course (after 50-odd years of observing the audio scene).
I actually did a meta analysis of all published ABX Null results I could find
My advice? Try to get out more.
D
Hi,
> Quite - but what tempts you to exempt the other five per cent?
There are rare cases where an ABX or ABX equivalent protocol has been used in blind testing where people did it right. Those tests rarely if ever see wide publication.
> I've yet to see an audio-related "ABX" test that would pass muster
> in a school-level psychology course (after 50-odd years of observing
> the audio scene).
I have seen very few.
> My advice? Try to get out more.
We have many rainy days in England... ;-)
Ciao T
At 20 bits, you are on the verge of dynamic range covering fly-farts-at-20-feet to untolerable pain. Really, what more could we need?
There are rare cases where an ABX or ABX equivalent protocol has been used in blind testing where people did it right. Those tests rarely if ever see wide publication.
Ah. The secret ABX-like test. Hadn't thought of that one . . .
We have many rainy days in England... ;-)
Hmmmm. Ever been to the west of Scotland?
D
Hi,
> Ah. The secret ABX-like test. Hadn't thought of that one . . .
Not so much secret as not particularly relevant to tales of cables etc...
> Hmmmm. Ever been to the west of Scotland?
Yes. Lovely place,except for the weather.
Ciao T
At 20 bits, you are on the verge of dynamic range covering fly-farts-at-20-feet to untolerable pain. Really, what more could we need?
You guys have no idea what a rainy climate is like until you live in Southern California. It just never stops raining here.
If you sell your Wilsons you can use the money to buy a lot of Nestle bottled water and use it to to keep your personal desert green. :-)
Tony Lauck
"Diversity is the law of nature; no two entities in this universe are uniform." - P.R. Sarkar
.
"Yes. Lovely place,except for the weather."
:)
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