EMC testing, what a good idea, I'm surprised it hasn't caught on yet in mainstream electronics.
🙂
Of course this from the creator of the BQP, I believe a device originally created to lower the noise floor for Sub. sonar systems!
The link in post #3091 is always worth a read...
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Do they have value? Perhaps the specific design does have "differences" , measurable differences. That's the con ....the hook..........the tweak that supposedly "makes a difference" Everybody is looking to sell "the hook", like a fisherman looking for the new sparkly lure for the fish, one which will attract. Nevermind that that shiny thing is not a living thing, not food, never was....just "bait"....& lots fall for it.
The differences are a fraction of a single percentage point...move around three feet from your listening "spot" & you've made far more difference than these cords. Bovine Excrement I say.......don't fall for it.
No Engineer nor Physicist with an ounce of integrity would design such a product...especially knowing its price-tag & its "value" within its intended usage.
_________________________________________________Rick.........
Yes they do what they do 🙄
Insulting those "engineers" and "physicists" ? Oh my, good gracious me ,how terrible
Well I'll say they have no value and insult them 24/7 😀
JC...I have followed the JB debate on a couple of threads and was teasing you - but to be sensible, I believe that JB is correct, but would go further. 🙂
I seem to remember that you quite recently posted the opinion that audio measurement techniques may well be measuring the wrong parameters. This infers that the measurements normally taken may be of secondary value in the assessment of sonic performance. This opinion further infers that such a situation may well be responsible for the accepted fact that some audio equipment despite coming through rigorous lab testing with flying colours may still sound dreadful and, visa versa, equipment which measures badly sometimes sounds excellent.
This dicotomy does lend weight to your contention and some of the genuinely knowledgeable and capable who post the same old same old ad infinitum would be better employed in seriously looking at this aspect rather than upholding traditional theory and practice - which may no longer be of absolute relevance.
Many years ago I expressed the view that EMI AND stray capacitance are two major enemies which adversely interfere with signal carrying cables doing their best. [But to simultaneously overcome both of these 'qualities' in cables - and other equipment - is both difficult and expensive.]
Overall, and despite the fact that I do believe that some cables have a character of their own, that market is populated by many chancers with no technical expertise who make both inaccurate claims and high (per item) profits.
I seem to remember that you quite recently posted the opinion that audio measurement techniques may well be measuring the wrong parameters. This infers that the measurements normally taken may be of secondary value in the assessment of sonic performance. This opinion further infers that such a situation may well be responsible for the accepted fact that some audio equipment despite coming through rigorous lab testing with flying colours may still sound dreadful and, visa versa, equipment which measures badly sometimes sounds excellent.
This dicotomy does lend weight to your contention and some of the genuinely knowledgeable and capable who post the same old same old ad infinitum would be better employed in seriously looking at this aspect rather than upholding traditional theory and practice - which may no longer be of absolute relevance.
Many years ago I expressed the view that EMI AND stray capacitance are two major enemies which adversely interfere with signal carrying cables doing their best. [But to simultaneously overcome both of these 'qualities' in cables - and other equipment - is both difficult and expensive.]
Overall, and despite the fact that I do believe that some cables have a character of their own, that market is populated by many chancers with no technical expertise who make both inaccurate claims and high (per item) profits.
In the past, people used to identify a market, then try to supply it with what it thought it needed or desired.
More recently, largely due to saturation of the more obvious markets, the approach has changed to - come up with a gadget or gimmick and then try to create a market (demand) for it.
This is where the sales/marketing people are essential, essence of snake oil is needed to keep this whole process lubricated.
In the audio world it seems that this process has become so refined now that it could almost be considered an art form in itself. Find an effect (no matter how dubious it's influence in the real world might be) then exaggerate it's consequences so that you can market an obscenely overpriced 'solution' to it.
There's one born every minute, you just need to target them then reel them in.
More recently, largely due to saturation of the more obvious markets, the approach has changed to - come up with a gadget or gimmick and then try to create a market (demand) for it.
This is where the sales/marketing people are essential, essence of snake oil is needed to keep this whole process lubricated.
In the audio world it seems that this process has become so refined now that it could almost be considered an art form in itself. Find an effect (no matter how dubious it's influence in the real world might be) then exaggerate it's consequences so that you can market an obscenely overpriced 'solution' to it.
There's one born every minute, you just need to target them then reel them in.
There is an alternative explanation: we are measuring the right parameters, but some people prefer them to have the 'wrong' values. There is plenty of anecdotal evidence for this.brianco said:
Sighted bias. Take away the reviewer's ability to see which component he is listening to and that will sort it all out.
Ohh yes.lots of back up for that: Audio Musings by Sean Olive: The Dishonesty of Sighted Listening Tests
Jan
Jan
Brianco, we have tried, and sometimes succeeded in making alternative tests on audio equipment and components, despite the usual engineers attempting to 'shout us down' or covertly derailing a paper prepared by us for the AES, or some other publication.
I go back to about 1980, when Matti Otala put out his first paper on PIM. It was short, highly mathematical, and there was nothing wrong with it, BUT it did not get into the AES Journal, because somebody high up did not want it there.
We saw the 'writing on the wall' that said that we could not get published anymore, except on the most mundane matters, or maybe an audio magazine would publish us.
As you must know, it is not easy to do groundbreaking measurements without extra quality test equipment, and nobody but we designers want to pay the price for it. I, for example have great test equipment from perhaps 20 years ago, but I still can't fund what I REALLY need to make some possible measurement breakthroughs. It would take every dollar that I have in reserve to do so, and where would I publish, if I did find something?
The other problem is that we are most probably actually measuring the WRONG THINGS. To be sure, IM and Harmonic distortion are important, but are they REALLY important below -110dB? I doubt it, except that many slightly distorted passive parts just might combine to make an audible signature.
Some measurement equipment has to be custom built, even today, to measure what we can mathematically predict. Yet, who has the time and money for such an endeavor, and what is the payoff? Glory? Fame? No, the only reward would be the satisfaction of creating a better understanding of what makes for audio differences, and THAT is even ridiculed by the ABX'ers who tell us that we are lying to ourselves and everyone else, when we hear differences in open listening. So we keep our heads low, and conduct our conversations between each other, and not on a forum such as this.
Yet, we do hear differences, and so do the audio reviewers, and finally the audio public.
That is why I am so well known in the field of audio design. I usually make stuff that works better than most of the stuff out there, and I can sell it by 'word of mouth' and not even advertising in the audio magazines.
I go back to about 1980, when Matti Otala put out his first paper on PIM. It was short, highly mathematical, and there was nothing wrong with it, BUT it did not get into the AES Journal, because somebody high up did not want it there.
We saw the 'writing on the wall' that said that we could not get published anymore, except on the most mundane matters, or maybe an audio magazine would publish us.
As you must know, it is not easy to do groundbreaking measurements without extra quality test equipment, and nobody but we designers want to pay the price for it. I, for example have great test equipment from perhaps 20 years ago, but I still can't fund what I REALLY need to make some possible measurement breakthroughs. It would take every dollar that I have in reserve to do so, and where would I publish, if I did find something?
The other problem is that we are most probably actually measuring the WRONG THINGS. To be sure, IM and Harmonic distortion are important, but are they REALLY important below -110dB? I doubt it, except that many slightly distorted passive parts just might combine to make an audible signature.
Some measurement equipment has to be custom built, even today, to measure what we can mathematically predict. Yet, who has the time and money for such an endeavor, and what is the payoff? Glory? Fame? No, the only reward would be the satisfaction of creating a better understanding of what makes for audio differences, and THAT is even ridiculed by the ABX'ers who tell us that we are lying to ourselves and everyone else, when we hear differences in open listening. So we keep our heads low, and conduct our conversations between each other, and not on a forum such as this.
Yet, we do hear differences, and so do the audio reviewers, and finally the audio public.
That is why I am so well known in the field of audio design. I usually make stuff that works better than most of the stuff out there, and I can sell it by 'word of mouth' and not even advertising in the audio magazines.
You play a few victim cards here, that's sad.
If your paper is up to standards it will get published.
If you provide proper subjective measurements that can be replicated by others, everyone will worship you for finding something new.
As long as you don't provide that evidence or don't stop making these claims that go against common knowledge, you are subject to ridicule.
If your paper is up to standards it will get published.
If you provide proper subjective measurements that can be replicated by others, everyone will worship you for finding something new.
As long as you don't provide that evidence or don't stop making these claims that go against common knowledge, you are subject to ridicule.
I design scientific instruments in my day job. I might well be interested in building custom equipment to discover new audio effects, but it would have to start with a serious public discussion of what the proposed effects might be and how experiments to test them might be designed.
I certainly agree that THD, IMD and the like are probably insignificant down at the <10ppm level, but I can't think of any other effects that would be audible but have escaped discovery so far.
Thank you JC for your explaination.
It seems of primary importance that there is some serious resesrch carried out on NON-STANDARD (audio, power and wiring (incl. cables)) using good quality available measurement systems and to discover what - of that which is traditionally ignored - is important to perceived audio performance.
A major drawback of course is that the usual suspects will be waving their banners regarding the methodology used at every stage of testing. (But the poor of spirit and flat-earthers we have with us for all time). Although they may have a point/s here and there, they are best in this instance ignored; otherwise there will be no possibility of discovering anything new if progress is impossible due to their rants. [And this proviso also includes the 'golden ear' group.]
Such research should, however, have agreed but wide parameters laid down simply to keep some focus of intent.
IF some genuinely new or surprising results are forthcoming then is the time to think of ratification using more specialised instrumentation.
It seems of primary importance that there is some serious resesrch carried out on NON-STANDARD (audio, power and wiring (incl. cables)) using good quality available measurement systems and to discover what - of that which is traditionally ignored - is important to perceived audio performance.
A major drawback of course is that the usual suspects will be waving their banners regarding the methodology used at every stage of testing. (But the poor of spirit and flat-earthers we have with us for all time). Although they may have a point/s here and there, they are best in this instance ignored; otherwise there will be no possibility of discovering anything new if progress is impossible due to their rants. [And this proviso also includes the 'golden ear' group.]
Such research should, however, have agreed but wide parameters laid down simply to keep some focus of intent.
IF some genuinely new or surprising results are forthcoming then is the time to think of ratification using more specialised instrumentation.
How can you discover it when it seems to disappear when 'ears only' testing is insisted on?
Take several amplifiers using very different technology, but all having good results on traditional standard tests. The different technology more or less guarantees some differences at low levels and differences on some things not included in the tests. Adjust their frequency response and signal levels to be identical, and where necessary add output resistors to equalise output impedance. Then 'ears only' tests show that they are indistinguishable to almost all people. The claim of 'wrong tests' would not predict this.
Then consider that when given a free choice many people choose (either deliberately or innocently) items which distort the signal in various ways (due to designer deliberate choice or incompetence). If minor adjustments (e.g. bias, or omitting the item altogether) can reduce the distortion people may complain that the 'musicality' has gone. This means that the alleged advantage of these items is inversely correlated with good engineering practice (such as appropriate bias), or the device adds 'niceness' to an audio signal which lacks it. In either case Occam's Razor insists we attribute 'niceness' to added measurable explicable distortion, not missing unmeasured unknown distortion.
Take several amplifiers using very different technology, but all having good results on traditional standard tests. The different technology more or less guarantees some differences at low levels and differences on some things not included in the tests. Adjust their frequency response and signal levels to be identical, and where necessary add output resistors to equalise output impedance. Then 'ears only' tests show that they are indistinguishable to almost all people. The claim of 'wrong tests' would not predict this.
Then consider that when given a free choice many people choose (either deliberately or innocently) items which distort the signal in various ways (due to designer deliberate choice or incompetence). If minor adjustments (e.g. bias, or omitting the item altogether) can reduce the distortion people may complain that the 'musicality' has gone. This means that the alleged advantage of these items is inversely correlated with good engineering practice (such as appropriate bias), or the device adds 'niceness' to an audio signal which lacks it. In either case Occam's Razor insists we attribute 'niceness' to added measurable explicable distortion, not missing unmeasured unknown distortion.
I personally think measurements got a bad name because of specsmanship. The hi-fi industry got into the habit of measuring its products in whatever way would give the most impressive numbers for marketing.
For example, it's easy to design a solid-state power amp that gives a nice low THD figure at 1kHz and about half rated power into 8 ohms. If you really want to know what it is made of, measure the THD at 10 or 20kHz into a 4 ohm load, at several power levels from 1 watt to the edge of clipping.
This shows up the weaknesses of the design by stressing it to the edge of its performance envelope, giving results more indicative of how the amp would actually sound than the traditional 1kHz measurement. The problem is that no sane manufacturer would print them because they would look 10x worse than their competitors' claims.
Actually this was the real story behind Matti Otala's "discovery" of "TIM". It was just caused by a lack of slew rate, and the same amps that suffered from TIM would have had lousy THD measurements at 20kHz and high power.
For example, it's easy to design a solid-state power amp that gives a nice low THD figure at 1kHz and about half rated power into 8 ohms. If you really want to know what it is made of, measure the THD at 10 or 20kHz into a 4 ohm load, at several power levels from 1 watt to the edge of clipping.
This shows up the weaknesses of the design by stressing it to the edge of its performance envelope, giving results more indicative of how the amp would actually sound than the traditional 1kHz measurement. The problem is that no sane manufacturer would print them because they would look 10x worse than their competitors' claims.
Actually this was the real story behind Matti Otala's "discovery" of "TIM". It was just caused by a lack of slew rate, and the same amps that suffered from TIM would have had lousy THD measurements at 20kHz and high power.
It was a little more involved than just 'slew rate, scopeboy. I know, because I helped write a paper on TIM. However, you are half right.
Mo-------- I do not have any idea what you know or where you get your opinions from. I get them from EXPERIENCE WITH, not belief in the AES.
Mo-------- I do not have any idea what you know or where you get your opinions from. I get them from EXPERIENCE WITH, not belief in the AES.
The cords have as much value as a 2 dollar ebay cord that does the same job, provided they do as good of a job. That's not an insult, they do have value provided they can do that much.
Scopeboy, an unusually non-linear input stage, as some IC's have been made, to get more 'slew rate' than typical is a good example. You must remember that TIM was first postulated more than 40 years ago. Then, IC's were pretty slow. Many power amps too!
Today, most IC's will pass a TIM test.
Today, most IC's will pass a TIM test.
I've seen current-feedback amps where the input stage has a nonlinearity that is the inverse of the classic long-tailed pair. Instead of dropping off to zero for large error signals, the gain shoots up towards infinity. Is that the sort of thing you mean? It certainly gives an impressive slew rate, but I was always a bit suspicious of the audio implications of it. 🙂
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Here's a picture:
An externally hosted image should be here but it was not working when we last tested it.
I doubt that this would really make much of a difference...
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