I think John Atkinson is still "learning " the Audio Precision test equipment he has had for the past 30 plus years. It seems he has trouble measuring cables, power cords and ANY sort of tweak device with it so far
What protocol, drive by bruuu ha 's ...
Big difference between bench jockeys and those producing real world results, i would like to see more than dogma when in dispute. No secret about THD/IMD, this has been discussed for more than 50 years, THD and IMD numbers are basically meaningless (starting at least with D.E.L Shorter from the BBC and Norman Crowhurst in the 1950s!). More recently , others have found slightly NEGATIVE correlation between subjective sound quality and THD+IMD. Human perception seems to be quite complicated and PATTERN related, with masking effects to boot.
OK,
So Bench jockeys dont have to listen , i get it , but understanding where those like JC, NP, RM and others who have to make products to work in the reproduction of music (art) and then have to balance the science , if not to do so , will be to their own detriment.
Both sides are not mutually exclusive, i wish such would extend into the discussions at hand..
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Indeed you won't. My suggestion is directed at someone who wants to determine if a measurement is significant in correlating with an audible effect. That's an engineering and perceptual psychology question.
It is not particularly useful for you, since your goals are moving boxes in the fashion market. That's a different goal than actually advancing the art and science of sound reproduction.
JN,
Did the college algebra many moons ago, don't have to use it much so once in awhile I have to think about it a bit. I actually like mathematics, always have but I do get rusty after long periods of not having to use it. Now my daughter is talking about chemical engineering and there I am not going to be a great help though I have had to deal with plenty of it. My father was a wiz at that, he loved chemistry and was a Bio-analysts by profession.
Anyone who wants to discount scientific methods will get nowhere fast. Even if you found something you probably wouldn't recognize it or have any clue how to duplicate the effort or use it in any reasonable manner. Not saying we have all the answers, but to discount these methods is to shoot yourself in the foot. Any explanation on why something is working becomes just a load of bs, you really wouldn't have a clue.
Did the college algebra many moons ago, don't have to use it much so once in awhile I have to think about it a bit. I actually like mathematics, always have but I do get rusty after long periods of not having to use it. Now my daughter is talking about chemical engineering and there I am not going to be a great help though I have had to deal with plenty of it. My father was a wiz at that, he loved chemistry and was a Bio-analysts by profession.
Anyone who wants to discount scientific methods will get nowhere fast. Even if you found something you probably wouldn't recognize it or have any clue how to duplicate the effort or use it in any reasonable manner. Not saying we have all the answers, but to discount these methods is to shoot yourself in the foot. Any explanation on why something is working becomes just a load of bs, you really wouldn't have a clue.
I don't think your brain is lying. The best set of ears I know of is very sensitive to emitter and source resistance in output stages. This is of course with speakers and not test equipment. The speaker output stage is critical and still holds some mysteries IMO.
There's only one way to know for sure, and that's by doing a real listening test.
So, I need to waste my time reading 30 to 45 year old papers, utilizing test equipment which by todays standards is useless, to read incoherent statements about silicon chips that cannot even be bought today??
Reasonable worst case?? Like as in, I had an old amp gathering dust, so modded it a tad to provide 400 watt heating pulses in less than 10 microseconds to a 4 ohm resistor dunked in liquid helium, to test the radiation heating capability of a magnet that will not enter production until at least 2017, for use in 2021? Seriously??
I used what I had... made it do what was needed...it met requirements. I tested a widget I made that is so far beyond current state of the art that there is no possibility that you will understand it before you retire from this planet. And you play word games to avoid scientific understandings? Do you not understand why high end analog is dying?? Why you are not the top of the heap in your craft?? (I believe you have that capability btw, but you derailed from those tracks.) I've offered my services to you free, you ignore them.
Perhaps the owners manual will help. I know that the HP manuals are a treasure trove. They were the first thing I perused.
jn
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Take a look at my Linear Audio article (available at their site), "Testing, One, Two, Three..."
Sounds like the typical, subjectively highly significant improvement that occurs when a seemingly minor alteration is made - the gestalt of the amplifier, which is the circuitry, DC conditions it operates under, its power supply and the quality of the mains power being fed to it has altered its dance, such that low level detail is less distorted than before. The impressive THD figure is just one manifestation of a pattern change - as everyone is screaming out, a measurement that goes to the heart of what the ears are picking up is called for ...
A thought on listening tests ... ones that describe a procedure use almost completely useless material, from my POV - a vastly better approach is to use recordings that are right on the edge of being tolerable, for the particular individual - his hearing will acutely attuned to the aspects that will allow him to do a thumbs up, or thumbs down.
This is akin to testing a car's "improved" suspension by running it on specially prepared, 'horror' sections of road surface ...
This is akin to testing a car's "improved" suspension by running it on specially prepared, 'horror' sections of road surface ...
I haven't seen Anyone here discount the science , but wait , who would have thunk it, a novel idea , ABX TESTING with level matching and a special switchbox....
talk about 50yr old ideas ...
Hi Scott
It is "on /off" modulation of a tone, the on / off rate begins at a low F and ends higher.
The evaluation is "if" the process under test can go from on to off rapidly.
The analogy might be the rapidly changing black and white bands.
The STIpa test has a high degree of correlation to ineligibility of random words and is language independent, that suggests this type of measurement is dancing in the area where the "information" held in the time domain.
When you include a loudspeaker in a generation loss test, better mtf's normally go along with more generations before subjectively falling apart.
Best.
Tom
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