jneutron said:
The nicest piece of equipment I know for such an application would be the 1MHz IOtech wavebook/516 with an optional simultaneous sample card. It may perhaps not meet the full speed requirements and it will cost you a few $ but it seems a nice box to start with.
ravon said:
As long as it can aquire 4 channels simultaneously, that'd do.
IOtech...ugh, I've a lot of that stuff here, admittedly pretty old..
Cheers, John
ravon said:
I'm not exactly sure what you mean.
My point is that I believe it will not be possible to distinguish differences between cables, using a test signal (meaning sine waves).
Andre Visser said:
From the first moment I mentioned test signals I did not exclusively mean sine waves....
Anyhow, it all boils down to treating the ABX test as a measuring instrument. Is that what you don't understand?
Re: Re: Re: Re: It's Obvious "IF" You're Open-Minded
Just because there is no apparent alternative at this time, doesn't mean we should dogmatically accept the results of these test, which are more often than not conducted under circumstances which have such large holes in them that any REAL objectivist would be able to drive a bus through. !
Just because there is no apparent alternative at this time, doesn't mean we should dogmatically accept the results of these test, which are more often than not conducted under circumstances which have such large holes in them that any REAL objectivist would be able to drive a bus through. !
Ah John, I see. From the energy ("intensity") calculation standpoint, the inverse square law is correct of course. But if we speak about delta pressure levels (as that is what we hear), it's only the 1/r loss relationship, p~1/r, p1/p2~r2/r1. Of course this could be regarded some sort of hairsplitting in the context of the current discussion.jneutron said:
These are very interesting points, now that I get it 😉.
I have no defnite answers... but some thoughts, sticking to your example:
1) At first we must make sure that such a percieved location shift (in case that it happens) is not only a psychoacoustical phenomen that happens just and only "between the ears" and not due to imperfect electronics etc.
2) If we find that it's not caused by psychoacoustical "misinterpretation", then the only cause of the effect could be some cross-channel signal modulation and/or signal dependent interchannel mismatch, way more complex than ie simple linear crosstalk which is known to be rather benign. This would be, im my belief, measurable (in some way ot the other, probably quite sophisticated) in specific parameters of both the individual channels (things like transient phase distortion from shifting dominant poles in the typical feedback type power amplifier) as well as interchannel influences.
3) If it's caused by some psychoacoustical effect we have a problem, then we have found a situation were the tricking of the brain has a flaw. Then we might run into the situation that some real and specific effects from less than perfect electronics might either partly compensate that problem or make it worse, while the "textbook" electronics would be only middle ground. Then the decision is, do we want to make the electronics perfect or do we want to make the result (the illusion) perfect? Many (including myself) would rather opt for perfect illusion... of course it would be a big deal to scientifically analyse and quantify such type of a probem and how a compensating "design error" has to be executed in the electronics to really work for a positive overall effect. He who finds the way how to dynamically distort the transfer functions in order to "generally sound better" would be a nobel prize candidate -- unless the answer is: make it as stable and signal-invariant as you can (which seems to be current SOTA belief for good reasons).
Ah, BTW, I did quite sophisticated and sensitive interconnect cable differential measurements and only found that there was no measurable (let alone audible with my humble reproduction means) difference between a 1m cable and it's precisly trimmed LRC-equivalent (in fact, only R and C were relevant), in a setup that tried to both mimic realistic signal source and sink conditions while taking parasitics like RFI and GND current out of the picture. Down to my noise floor at that time, -140dB ref 2Vrms (with a 24/96 semi-pro soundcard), with any signal. Only recently I learned a method how to dig down 20dB further in the thermal noise, but honestly, I've lost interest in these matters, disappointed from the "non-event" (perhaps a from wrong test approach, who knows) and it isn't that important to me at all... while not denying that there might still be audible differences to others, under specific real life circumstances.
- Klaus
tnargs
My answer is most people would not question the placebo's inertness, because we don't find it hard to accept that the mind is so powerful it can affect the physical body.
But in audio land when an inert cable is listened to and it "cures" a problem, subjectivists immediately question the inertness of the cable.
Is this sensible ?
cheers
My answer is most people would not question the placebo's inertness, because we don't find it hard to accept that the mind is so powerful it can affect the physical body.
But in audio land when an inert cable is listened to and it "cures" a problem, subjectivists immediately question the inertness of the cable.
Is this sensible ?
cheers
KSTR said:
thank you. !! 😀
I have never said there is (or isn't).
but.....
A lot of anecdotal evidence that there MIGHT BE,
NO solid, real life, proof that there isn't !!
No.Alan Hope said:
But if that general anaesthesia was actually a placebo and the person still falls asleep, well yes you could say that.
jneutron said:
True and true, we are all inclined towards magical thinking, and it sure is interesting.
Jakob2 said:
Disturbing news. If the effect doesn't exist they could be hearing things we can't measure.
Behringer went on a world tour? When? Did you mean Uri, as in Geller? With the "special" see-I-told-you-some-humans-have-better-abilities-than-others spoon bending skills? Gathered through lots of "experience" and "very careful" concentration?tnargs said:
Well, about Andre doing that world tour demonstration thing...you see, Uri had some, um, err, "problems" when it came time to demonstrate "outside the back yard" so to speak. That does not mean he cannot bend spoons!!! It just means he, um, err, could not bend a spoon in that specific instance of the test. With all those nasty scienceguytype onlookers watching intently. Must have been rather stressful. Think he said so himself...tnargs said:
jneutron said:
Yah, lunchtime posts can be hasty affairs. Judging by the number of responses since then, I take it BHaven has slightly different employee internet use policies during work hrs than mine? Or do you have some time off, in which case how goes the housework and dielectric hunt? 😀 Still trying to figure out the ITD fuss with fictitious soundstages, but hey did I mention I liked dipole late reflection (but DBT friendly) nutrasweetning? 😉
cheers,
AJ
Andy Graddon said:
Andy, how many times do we have to ask? Why don't you and the folks who know exactly how valid DBT's should be performed and possess these superlative self acclaimed "hearing" perceptiveness test yourself and demonstrate once and for all these so far elusive "abilities"? It would certainly be accepted by me! Hows about it? No more excuses, like the Nike ad says "Just do it" and demonstrate them "Just Listening" skills.
The world awaits....
cheers,
AJ
AJ,
I have no need to do that. I don't feel the need to prove anything. You are the one with the need to prove stuff.. why I can't even start to imagine ????
But just for you, if you are going to bother with an ABX test that might have some sort of possible reality to it, it should be carried out in as close to normal listening conditions as possible. A regimented testing regime certainly isn't that, which puts ABX out of the picture straight away, so why bother.
See if you can figure it out some time ......... its not that hard, even for you.
gees, why not just sit back and actually listen for a while, maybe you will learn something. !!! nah, I doubt it.
Now...
Put your microphones to the test.
Please provide a basic simple frequency response curve of your speakers measured at normal listening position in your lounge room.
I have no need to do that. I don't feel the need to prove anything. You are the one with the need to prove stuff.. why I can't even start to imagine ????
But just for you, if you are going to bother with an ABX test that might have some sort of possible reality to it, it should be carried out in as close to normal listening conditions as possible. A regimented testing regime certainly isn't that, which puts ABX out of the picture straight away, so why bother.
See if you can figure it out some time ......... its not that hard, even for you.
gees, why not just sit back and actually listen for a while, maybe you will learn something. !!! nah, I doubt it.
Now...
Put your microphones to the test.
Please provide a basic simple frequency response curve of your speakers measured at normal listening position in your lounge room.
I don't think Andy has any idea as how and why speakers are measured. And if he does, it's just another impossible setting requirement. 
Andy Graddon said:
Not necessarily. The purpose of listening to music is, err, listening to music. The purpose of an ABX test is to find out if two pieces of equipment, or cables, or whatever, produce a verifiable and repeatable audible difference.
To do that, you would want to exclude all non-sound related perceptive inputs, like size, color, price, peer opinion, prejudice, all the myriad things that normally add to your perceptive experience, but you don't want if you are interested in *only* the sound differences.
So, I fail to see why that should take place in the normal listening environment.
Jan Didden
In a dbt situation you´re using a listener as measurement tool.
The farther away from ´normal listening conditions´the longer will be training needed to work under the new conditions as well as before.
It seems self-contradictiory to do blind tests, because humans are prone to all kinds of suggestive influences, but then to bring a lot of new external factors into the test.
Sometimes it is difficult to evaluate all external factors before, that´s one of the reasons that controls are mandatory, because the experimentator otherwise will never know, if his `measurement tool´ was working as exspected. 🙂
My current assignment involves wiring a 2400 foot long machine 5 megawatts at 500 mhz, 900 magnets 10 amps to 400 amps, coupla megawatts of power dissipation,switching supplies in the 50Khz to 80Khz range...motion control with 100 khz 2 and 3 phase bridges..position sensors in the micrometer range... rad hard tray rated, ALL in about 5000 feet of 12 inch tray. This is a recipe for an EMI disaster if not done correctly.
Current EMI practices are shabby. Current ground loop sensitivity understandings are shabby. Current twisted wire pair understandings are shabby..What people understand about inductance and high accuracy electronics basically can fit on the head of a pin..(my apologies to those who do not fall into this category).
Many times I can google to find information I require. Unfortunately, there are times when a google search goes blank..
Embedded within the "can a cable change be audible" argument is:
1. Ground loop sensitivity...a work topic for me, discussion here is extremely valuable to that end.
2. Wire external inductance/coupling: again, reduction of external field aids in reduction of coupling.
As a result of my forays into high end audio (discussions such as the current one), I have become rather (shall we say) "adept" at these particular topics, and that has absolutely positively been a good contribution to that which I do at work.
Just finished tiling a shower. Porclean is some hard stuff to drill, sheesh..
First dielectric choice I didn't like, the conductor spacing was too easily altered by physical movement, so inductance was too dependent on radius of curvature of the pair...I still work on..
Cheers, John
Current EMI practices are shabby. Current ground loop sensitivity understandings are shabby. Current twisted wire pair understandings are shabby..What people understand about inductance and high accuracy electronics basically can fit on the head of a pin..(my apologies to those who do not fall into this category).
Many times I can google to find information I require. Unfortunately, there are times when a google search goes blank..
Embedded within the "can a cable change be audible" argument is:
1. Ground loop sensitivity...a work topic for me, discussion here is extremely valuable to that end.
2. Wire external inductance/coupling: again, reduction of external field aids in reduction of coupling.
As a result of my forays into high end audio (discussions such as the current one), I have become rather (shall we say) "adept" at these particular topics, and that has absolutely positively been a good contribution to that which I do at work.
AJinFLA said:
Just finished tiling a shower. Porclean is some hard stuff to drill, sheesh..
First dielectric choice I didn't like, the conductor spacing was too easily altered by physical movement, so inductance was too dependent on radius of curvature of the pair...I still work on..
Cheers, John
Agreed.KSTR said:
The task is to identify the least amount of disturbance that will upset the image relationships. Sadly, as we can see, simple harmonic distortion and frequency response does not look for that which can alter the image.
My interest in localization was spurred by the quest for the relative levels of those disturbances which can be heard AND measured..
Oddly enough, much of what can affect the amplifier is consistent with my current work..I like the crossover in disciplines, it keeps it interesting..
Cheers, John
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