Hi,
There would be room to quibble. In some areas -110dB may be insufficient, in others it may be too stringent.
That depends on what we wish to find.
If I desire to reliably know the steady state THD of a DUT and the breakdown by harmonics then the AP2, with all it's op-amp's etc. is a perfectly decent choice. Of course I can accept it's findings, no matter how it works.
But, something like the above is ALL that the AP2 can give you. It can give you a quantitive answer to a specific question, regarding a specific quantity.
This, strictly speaking is not possible. You CANNOT make a recording that is "better than live" objectively, however, subjective preferences are another thing. It is possible to make something sound more "likable".
Only a complete and utter ejit who has no idea about how the human hearing works would make such a suggestion as anything but troll bait.
It has been said here many times by many, adding distortion does not give "vinyl sound" or "tube sound".
If it did, we all would be listening to CD's produced with the usual low-end pro-sumer garbage gear (which some mistake as "Pro" - the relation is about like that between a Hasselblad and a Sony "Megazom 30 Megapixel" point and shoot camera) and with suitable DSP Plugins applied and gush how "analog" things sound.
Ciao T
There would be room to quibble. In some areas -110dB may be insufficient, in others it may be too stringent.
That depends on what we wish to find.
If I desire to reliably know the steady state THD of a DUT and the breakdown by harmonics then the AP2, with all it's op-amp's etc. is a perfectly decent choice. Of course I can accept it's findings, no matter how it works.
But, something like the above is ALL that the AP2 can give you. It can give you a quantitive answer to a specific question, regarding a specific quantity.
This, strictly speaking is not possible. You CANNOT make a recording that is "better than live" objectively, however, subjective preferences are another thing. It is possible to make something sound more "likable".
Only a complete and utter ejit who has no idea about how the human hearing works would make such a suggestion as anything but troll bait.
It has been said here many times by many, adding distortion does not give "vinyl sound" or "tube sound".
If it did, we all would be listening to CD's produced with the usual low-end pro-sumer garbage gear (which some mistake as "Pro" - the relation is about like that between a Hasselblad and a Sony "Megazom 30 Megapixel" point and shoot camera) and with suitable DSP Plugins applied and gush how "analog" things sound.
Ciao T
I would think that can only work if you use linear models for both complex frequency response (mag and phase) and complex output impedance, to get to any possible nulling in the first place.
Otherwise there will be a conceptual difference (the linear response variation caused by actual loudspeaker current producing a I*Z drop along the output impedance) as well as an overlaid swamping nonlinear distortion, the distorted nature of that speaker current. Even with a perfect amp (say, perfect opamp, single pole model) with truly ohmic Zout of 10mR the test would fail, depending on the real-world speaker load. And a complex dummy load still provokes linear distortion along a perfect Zout that must be acutely dealt with first in order to see the real (nonlinear) differences of the amp vs its linear model.
That's less important than the question, "At what level will human listeners be unable to distinguish differences between output and input by ear only?" At that point, it's as perfect as it needs to be. That unfortunately would present a problem for marketeers, magazine writers, and would-be gurus...
Hi Sy,
I am shocked that I actually agree with you. Of course, tests used to establish such limits would need to be carried out to quite seriously scientific standards.
The only such tests I am aware of having been done re. audibility to sufficient standards regarded perceptual coding (MP3, AC3 etc.) and we can learn a fair bit from these tests, however as they had subtly different questions from those you and I listed independently (and phrased differently) we cannot directly extrapolate.
Again, we agree.
I cannot see why this would be the case. If the tests to establish audibility are done with due care, diligence and controls I see no issue. Issues only appear when unscientific nonsense is being put forward under the mantle of being scientific and actually offering evidence of the true situation, when nothing could be further from the truth.
When I moved to the UK at least two of the magazines published the results of blind preference testing of amplifiers, cd-players etc. (usually in the "Budget Class") each and every month. Did they find everything sounded the same and no differences existed?
Hardly...
Also, I did post a summary of a blind test I did a page or so back. The silence on your part regarding this has been deafening. No suggestions what we did wrong and why we reliably heard differences that could not be measured?
Ciao T
I am shocked that I actually agree with you. Of course, tests used to establish such limits would need to be carried out to quite seriously scientific standards.
The only such tests I am aware of having been done re. audibility to sufficient standards regarded perceptual coding (MP3, AC3 etc.) and we can learn a fair bit from these tests, however as they had subtly different questions from those you and I listed independently (and phrased differently) we cannot directly extrapolate.
Again, we agree.
I cannot see why this would be the case. If the tests to establish audibility are done with due care, diligence and controls I see no issue. Issues only appear when unscientific nonsense is being put forward under the mantle of being scientific and actually offering evidence of the true situation, when nothing could be further from the truth.
When I moved to the UK at least two of the magazines published the results of blind preference testing of amplifiers, cd-players etc. (usually in the "Budget Class") each and every month. Did they find everything sounded the same and no differences existed?
Hardly...
Also, I did post a summary of a blind test I did a page or so back. The silence on your part regarding this has been deafening. No suggestions what we did wrong and why we reliably heard differences that could not be measured?
Ciao T
I'm going to say something in all seriousness, and if you like, it's also directed to dvv. Engineers, especially those with a stake in the outcome (not of that particular test, perhaps, but of that sort of test in general) rarely have the knowledge and background to design and set up proper sensory tests; sometimes that leads to deliberate error, sometime to inadvertent error. The very best thing they can do, lacking the on-site availability of a sensory test expert, is to hire a magician. If the magician is a specialist in mentalism, so much the better. Let the magician set up the blinding, scoring, and tabulation protocols.
Two things related to DVV here:
1. I get to walk away from this because I'm not an engineer, and
2. As far as I am aware, you have not stated what was wrong with what we did. I may have missed it, and if I did, some directions, please.
On a personal note, I resent your attitude towards my cousin Thorsten. Yes, cousin. Like most things in this thread, THEORETICALLY all people of German descent are related from God know how far back, and THEORETICALLY my 25% of Austrian blood (Austrians are just expatriate Germans, trust me) makes me a distant relative of Thorsten, many times removed.
Exactly the same thing applies to Wavebourn - we are also very probably related, some 13+ (and possibly as far back as 23+) centuries ago, but hey, THEORETICALLY blood is a lot thicker than water, even if many times removed.
If you are Caucassian, you should apply much more tact and care when addressing your THEORETICALLY kinsmen; the archetypical "white man" is quite rightly called Caucassian, and the Caucassus mountains are in what is Russia today. Slavs originate very directy from right that there ground zero, with a big move in the 7...10th century, when Slavs moved into the Balkans, to become Serbs, Croatians, Slovenians, Macedonians and Montenegrins later on.
When Serbs moved in here, they were pagans, and it was two Greek Orthodox Christian priests who gave us our alphabeth (one was named Cyrrilus, hence the name Cyrillic alphabeth), our faith and some of our customs. To this day, I can read Greek, even if I don't understand most of it, so THEORETICALLY, Greeks are also my cousins. Also Wavebourn's, because in his native lanugage he also uses Cyrrilic, so he too is THEORETICALLY a cousin to the Greeks.
ANYTHING is theoretically possible, even such cosmic events like finding a grain of honesty in a politician's head.
With so much theory being flung around, no wonder so few mention actual, real life issues any more.
Which brings me back full circle to my question from above: what did my friend and I do wrong in our internal wiring test?
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You didn't consult someone who knows how to set these tests up properly. The information you gave missed nearly all of the critical points in setting up a good controlled test, so the chances are that these weren't considered. The statistics you gave were inconsistent with your descriptions of the magnitude of the differences. I'm not being critical of you as an engineer- this is just not something engineers know how to do any moreso than sensory psychologists know how to set up the bias arrangements on a source follower.
Next time, hire a magician, then once a tight protocol is established, follow it to the letter. You're making an extraordinary claim and that requires particular care and transparency in how the data are obtained.
Next time, hire a magician, then once a tight protocol is established, follow it to the letter. You're making an extraordinary claim and that requires particular care and transparency in how the data are obtained.
Hi Sy,
I was quite candid with the test conditions.
If you have any specific issue you may wish raise I will be happy to hear it and see if the concern is valid or based on misunderstanding.
Well, now any subjective test not set up by a "sensory test expert or a stage magician" are automatically invalid (howls of anguish and despair from the ABX Mafia)?
Or are they only invalid if YOU dislike the results, or worse, the implications of the results?
Enquiring minds do want to know, if you had particular magician in mind (like the Amazing Randi who can magically make any differences between anything disappear, or at least as top escape artist escape having to pay up) and what specific function the Magician would full that for example =ROUND(RAND()*(3-1)+1,0) in Excel (for my case of testing three different items) cannot?
Or is the Job of the Magician to create the illusion that real differences have suddenly all disappeared?
Ciao T
I was quite candid with the test conditions.
If you have any specific issue you may wish raise I will be happy to hear it and see if the concern is valid or based on misunderstanding.
Well, now any subjective test not set up by a "sensory test expert or a stage magician" are automatically invalid (howls of anguish and despair from the ABX Mafia)?
Or are they only invalid if YOU dislike the results, or worse, the implications of the results?
Enquiring minds do want to know, if you had particular magician in mind (like the Amazing Randi who can magically make any differences between anything disappear, or at least as top escape artist escape having to pay up) and what specific function the Magician would full that for example =ROUND(RAND()*(3-1)+1,0) in Excel (for my case of testing three different items) cannot?
Or is the Job of the Magician to create the illusion that real differences have suddenly all disappeared?
Ciao T
Hi,
Why would the claim be extraordinary. Where is any claim anyway?
What is presented is an observation, namely that "under blind conditions in this and that fashion we obtained the following results".
There is no claim.
You may argue that certain care was not taken. As someone who has been working with blind tests for audio since the 80's I will on my part take exception to that.
You may argue that the protocol or settings where not suitable, in which case you surely be more precise than just general hand-waving.
As I mentioned I have used very similar arrangements at AMR for many tests, though we also conduct some tests sighted. And yes, we do get negatives in our tests, more often than positives for example.
We tested many (SMD) resistors that did not give rise to any significant preference for example, we find many generic plastic capacitors (regardless of price, advertising budget and claims made) to be essentially so alike that no strong preference is found.
So, if you have any real criticism to offer, or better advise than "hire Randi" I'll consider it, otherwise I may simply limit myself to reading my copy of Aesop...
Ciao T
Why would the claim be extraordinary. Where is any claim anyway?
What is presented is an observation, namely that "under blind conditions in this and that fashion we obtained the following results".
There is no claim.
You may argue that certain care was not taken. As someone who has been working with blind tests for audio since the 80's I will on my part take exception to that.
You may argue that the protocol or settings where not suitable, in which case you surely be more precise than just general hand-waving.
As I mentioned I have used very similar arrangements at AMR for many tests, though we also conduct some tests sighted. And yes, we do get negatives in our tests, more often than positives for example.
We tested many (SMD) resistors that did not give rise to any significant preference for example, we find many generic plastic capacitors (regardless of price, advertising budget and claims made) to be essentially so alike that no strong preference is found.
So, if you have any real criticism to offer, or better advise than "hire Randi" I'll consider it, otherwise I may simply limit myself to reading my copy of Aesop...
Ciao T
I've given you the best advice possible, assuming you want to know what's audible versus what's sellable. Hire an experienced expert in sensory analysis or go cheap and hire a decent magician.
Sy,
I am not interested in "what is audible", nor do I have funding for this.
Though the results of the stuff I do test has a bearing here, as for several people to express reliable preferences in complete absence of any measurable differences and any that can be seen strongly suggests real audible differences where present, especially if three out of four people present did not even have the faintest clue what the differences where.
The "bad sound" amp identification went well and easily past the requirements for .05 significance and beyond. My own identification of the reference amp also scraped by for .05.
The rest gave us less confidence. It is perhaps more significant tat sonic characterisation of the "bad sound" amp was basically the same, with different words, but the same sonic character being described. Do we really need to run a statistical analysis on this to work out how unlikely this kind of result is, by chance?
Well, given that magician makes his living by deliberately deceiving people for monetary gain, I would be careful to use the word "decent" in the context. The only (self professed) "experienced expert in sensory analysis" in my ken, based on how he earns a living (also by engaging in public deception), also does not strike me as overly trustworthy, so I fear I must decline the advise and stick to my own devices.
Ciao T
I am not interested in "what is audible", nor do I have funding for this.
Though the results of the stuff I do test has a bearing here, as for several people to express reliable preferences in complete absence of any measurable differences and any that can be seen strongly suggests real audible differences where present, especially if three out of four people present did not even have the faintest clue what the differences where.
The "bad sound" amp identification went well and easily past the requirements for .05 significance and beyond. My own identification of the reference amp also scraped by for .05.
The rest gave us less confidence. It is perhaps more significant tat sonic characterisation of the "bad sound" amp was basically the same, with different words, but the same sonic character being described. Do we really need to run a statistical analysis on this to work out how unlikely this kind of result is, by chance?
Well, given that magician makes his living by deliberately deceiving people for monetary gain, I would be careful to use the word "decent" in the context. The only (self professed) "experienced expert in sensory analysis" in my ken, based on how he earns a living (also by engaging in public deception), also does not strike me as overly trustworthy, so I fear I must decline the advise and stick to my own devices.
Ciao T
Well said, Thorsten. While we are direct competitors, I like your approach, especially philosophically.
I chose to make the best that I can, and THEN put a price tag on it.
When I have to make something cheaper, it is at the price of slightly marginal performance. That has been my life experience, and it has worked for the last 39 years to make what many say are better products, than the mid-fi crowd,(even with IC's, recently).
I chose to make the best that I can, and THEN put a price tag on it.
When I have to make something cheaper, it is at the price of slightly marginal performance. That has been my life experience, and it has worked for the last 39 years to make what many say are better products, than the mid-fi crowd,(even with IC's, recently).
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Guys,
Based on genetics the whole Asian, Caucasian and so on race (excluding africans) can be traced to a very small group of africans that left Africa and apparently moved to the middle east. Or humans where created from clay and mud around 6,000 Years ago by a divine being. Or where spirit beings marooned on earth by Xenu. Take your pick.
Either way we are all closely related and even if where not, being human we should see each other as Brothers.
Certainly I view those that give me hard time here as my dear brothers...
Because you cannot choose your family, only your friends.
Ciao T
I agree that Salas may be my cousin, but in Poland they used Latin alphabet.
Based on genetics the whole Asian, Caucasian and so on race (excluding africans) can be traced to a very small group of africans that left Africa and apparently moved to the middle east. Or humans where created from clay and mud around 6,000 Years ago by a divine being. Or where spirit beings marooned on earth by Xenu. Take your pick.
Either way we are all closely related and even if where not, being human we should see each other as Brothers.
Certainly I view those that give me hard time here as my dear brothers...
Because you cannot choose your family, only your friends.
Ciao T
I was pulling it out. He complimented my command of the French Drop.
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