SY said:
So much to try and so little time! I have to prioritise so I am using my rational side to explore audioland, which means that some places will have to remain unexplored, as in the above list.
Just why other folk spend so much time on these things seems a mystery to me. I can only surmise that they, like everyone else, are after something, and for them that could be a feeling that they are at the cutting edge of technology, ahead of the curve, and someday they will be proved right by the very science that they now ignore.
Of course I could be completely wrong.
BudP
Another good post. In all sincerity you are a brilliant writer, you make me want to believe, it all sounds so plausible. Keep posting. (no sarcasm intended, please take it as a compliment from a non believer) cheers
Another good post. In all sincerity you are a brilliant writer, you make me want to believe, it all sounds so plausible. Keep posting. (no sarcasm intended, please take it as a compliment from a non believer) cheers
Thank you SY. I will dig these out of whatever hidey hole they are in.
Don't believe. Try this stuff out please. This is the reason I have posted on all of the various kinds of madness that I have explored. You can duplicate a lot of this stuff, for very nearly free. DIY after all!
Bud
Don't believe. Try this stuff out please. This is the reason I have posted on all of the various kinds of madness that I have explored. You can duplicate a lot of this stuff, for very nearly free. DIY after all!
Bud
fredex said:
What fredex said
If there is one thing I have learned from when I did color correction on prints is that it is very difficult to percieve small amounts of manipulation to the photo. Some of the adjustments I would do you really had to A/B or do a side by side comparison to see the difference.
More often than not an enhancement to the high end of the spectrum is percieved as an increase in detail and nothing more - not brighter even though it is.
If I was forced to color correct the way a lot of people expect an audio test to be conducted it would be very hard for me to honestly detect small differences. It would be like me being required to close my eyes for 5 seconds before looking at the other print. And in that case - I have tried this - it's hard for me to notice anything at all.
fredex said:
A very good point! However I don't ever remember that happening where I worked. I do remember artists liking or disliking a new print run for "emotional reasons." But we at the shop could see the differences.
I have proposed (somewhere on this forum) wiring up the listener to test for heart rate, muscle tension, that sort of thing. Really...
Key said:
Yes indeed!! That's what has always bothered me about audio tests, it's so hard to compare 2 things at once. 😡 Much easier with images, even many at once. Therein lies so much of the trouble with audio listening tests.
Of course none of the equations mean anything at that kind of extreme - sort of like applying the Lorentz–FitzGerald contraction hypothesis to the notion that if a person could travel at the speed of light he would be everywhere at once.
What is interesting to me is that (IIRC) skin depth was originally defined as the depth at which the plane wave lags by one radian and the current density at that depth is e^-1 as a consequence of that definition. One wonders if it it possible to hear such "smearing" due to phase lag. The complexities of calculating such a thing involving music signals would be enormous.
John
Well that was what I wanted to know.
Can you explain what the smearing sounded like a little better? Anything that sticks out as being obvious or that you could put into other words besides time/lag or another synonym for phase response?
Can you explain what the smearing sounded like a little better? Anything that sticks out as being obvious or that you could put into other words besides time/lag or another synonym for phase response?
I can try. Purely hypothetical situation to follow, or Auplater will have a fit.
When you get hold of a set of ribbon driver based speakers your first response to them is that they are thin. They seem tinsely and fast and while you can tell that everything is very finely detailed, it is difficult to appreciate. You take these bare Litz cables and slip them into a cotton sleeve, XXL shoelaces, only to find that the sound seems to have become diffused slightly. Were you plagued by a potent imagination, you might describe it as being able to hear the woven pattern of the cotton threads, within the sound the speakers are making. But of course, that could not be.
So you begin to add pieces of shrink tube and notice that this, tinsely, fast sound, with such clean and hard edges, begins to grow softer, almost as if it were being blurred.
Then you notice that the blurring has information content, it is not just a smear and you begin to realize that the instruments and their sounds have a sort of gradient that was not really noticeable before. Were you to strip off all the dielectric, back to the bare wire, you would still hear this seemingly new found information content, but it has again become less accessible. But now you know it is there and can find it, even without the pieces of plastic.
As you return those pieces of plastic to the Litz wire you will be very aware of the increase in information, to the edges of sounds and a greater degree of internal gradient within the musical notes. As you add more plastic this sense of greater detail unfolds further and then, with the addition of an extra piece, the sound seems almost strained, but at the same time it also seems fat and sluggish, overblown and hollow somehow.
If you continue to add pieces of plastic, this entire house of sonic cards collapses, into a what could be compared to looking through a rain drenched window, at a gray, leaden sky.
It is all still music, but you have simply gone too far.
Does this paint a picture with any meaning for you?
Bud
Thanks Bud
Well I can see what you were saying but I guess I was sort of fishing for something different from you.
One of the clear signs of a system with decent phase coherancy for me - this was after switching DACs mind you but they are from the same company and sound very similar if not the same in almost all respects - was percieving sounds that are out of phase in regards to left and right channel relationship (reverbs and echos mostly) to come from the sides of my head or behind my head. And I admit that I think the better DAC accentuated or made the effect more obvious and that I could probably go back to the worse DAC and notice it to a lesser effect. But I also have to admit I may be wrong about the whole thing and I was just expecting a change because hey it's my new DAC and I want to like it.
Another problem I have is that I have experienced weird time shifts with songs after mixing them for long hours. It can all of a sudden maybe the next day or after getting fatigue sound like the song is in slow motion um but not. It messes with me at times and it makes me doubt the bpm I am using is correct for the song. I call it "song fatigue". And I think it might be from my natural inclination to improvise or change a song - rarely is the live version as slow as the studio version.
Anyway just some random thoughts/doubts on the subject. sorta 🙂
Well I can see what you were saying but I guess I was sort of fishing for something different from you.
One of the clear signs of a system with decent phase coherancy for me - this was after switching DACs mind you but they are from the same company and sound very similar if not the same in almost all respects - was percieving sounds that are out of phase in regards to left and right channel relationship (reverbs and echos mostly) to come from the sides of my head or behind my head. And I admit that I think the better DAC accentuated or made the effect more obvious and that I could probably go back to the worse DAC and notice it to a lesser effect. But I also have to admit I may be wrong about the whole thing and I was just expecting a change because hey it's my new DAC and I want to like it.
Another problem I have is that I have experienced weird time shifts with songs after mixing them for long hours. It can all of a sudden maybe the next day or after getting fatigue sound like the song is in slow motion um but not. It messes with me at times and it makes me doubt the bpm I am using is correct for the song. I call it "song fatigue". And I think it might be from my natural inclination to improvise or change a song - rarely is the live version as slow as the studio version.
Anyway just some random thoughts/doubts on the subject. sorta 🙂
I think most of us have had an experience of phase so out of whack that you comprehend it as coming from some place other than the ordinary. I am aware that some folks have made an art form of this, using it in computer games so that even with just two channels you still get a location ID from approaching threats that are most definitely not in front of you.
I would be interested to read about how this is done, just to get some notion of what characteristics cause some recorded music to have substantial information coming from lateral positions beyond the speakers, even if you turn your head and look directly at the perceived source.
Beyond this tiny and trivial bit, I am ignorant.
Bud
Well I know a lot more on the subject than I would really like to get into at the moment.
But basically a lot of reverbs are designed this way and a lot of engineers like throwing the signal out of phase on the echos.
You can do some really weird out of speaker localization with 90 degree linear phase shifters but the problem with those is they almost always sound degraded - because they are.
But anyone who has had the bright idea of wanting a sound to come out of every speaker at the same time in a mix has had to deal with the way we interpret phase relationships. Stereo, Discrete Surround etc.. if you place the same exact sound in all of the channels at the same time it will be perceived as phantom center front. With this limitation you sort of realize there must be some phase difference if you are ever going to get the same sound to appear to come out of more than one speaker at a time. Or more precisely to keep it from folding down to mono/phantom center.
But basically a lot of reverbs are designed this way and a lot of engineers like throwing the signal out of phase on the echos.
You can do some really weird out of speaker localization with 90 degree linear phase shifters but the problem with those is they almost always sound degraded - because they are.
But anyone who has had the bright idea of wanting a sound to come out of every speaker at the same time in a mix has had to deal with the way we interpret phase relationships. Stereo, Discrete Surround etc.. if you place the same exact sound in all of the channels at the same time it will be perceived as phantom center front. With this limitation you sort of realize there must be some phase difference if you are ever going to get the same sound to appear to come out of more than one speaker at a time. Or more precisely to keep it from folding down to mono/phantom center.
jlsem said:
Not really. Fourier's theorem applies to all signals- music is not an exception.
Scale is the greater issue- what's the amount of phase lag you're talking about? Plug in some typical values for Home Depot 12 gauge extension cord at 1kHz and 20kHz, then explain how that relates to the audible changes from studio delay lines.
The other thing to consider is the orthogonality of the current variations from skin depth and the Poynting vector. This was a severe flaw in a paper I once read that had been rejected by a peer-reviewed journal, but happily published in a tweak magazine (presumably under the assumption of "Baffle 'em with BS" given that the average reader wouldn't be terribly familiar with Stokes' Theorem but would be impressed with all those upside down triangles and cool snakey S symbols).
If this were actually a serious issue, hams couldn't use RG8 for 10 meters, three orders of magnitude higher than the highest audible frequency (more for old codgers like me).
It's the same for haptic and organoleptic testing. If you want to determine the effect of two types of plastic on the taste of cheese slices, they can't be chewed together! Yet wine tasters can consistently tell Volnay from Gevrey, and skilled listeners can detect fabulously small level differences and frequency response errors...
SY said:
Well that's pretty good, considering how close there are (Côte-d'Or, both). But I wonder if I could tell the 2 towns apart, blindfolded - by sound only? Maybe.
Tasting the effects of 2 different plastics seems more related to cable tests. Same "message", different wrapper.
I'll bet that I can identify cables by taste, too!
Not trying to be a wise guy - just wondering how sensitive the different senses are. 😀
I was wondering if wine testers could still tell the difference between the two wines if they had to try them randomly 10 times each in a few minutes.
That's very often the case.
But you (once again, over and over and over) are making up restrictions that aren't there.
But you (once again, over and over and over) are making up restrictions that aren't there.
It is a restriction to you.A friend wine tester does not seem to agree with you."That's very often the case?"It seems to me that this comment of yours will turn something like "30 years of null............"case.
Maybe it's the language barrier, but those sentences make no sense to me. Could you try to rephrase that?
Most who take part in this discussion say the same things over and over and over.I said "I was wondering....."To me this means I need an opinion.How did you come to the conclusion that I'm making up restrictions that are not there?
You put in a restriction that not only doesn't need to be in valid tests, it often isn't- the rapid switching hurry-hurry restriction.
As it happens, that often gives good results in some sensory tests (cork taint scans in winery QC, for example), but in less-routine situations, experimenters generally allow the subjects to work as rapidly or slowly as they think they need.
As it happens, that often gives good results in some sensory tests (cork taint scans in winery QC, for example), but in less-routine situations, experimenters generally allow the subjects to work as rapidly or slowly as they think they need.
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