Did Amir Change Your Mind About Anything?

Curious what @amir_asr would say about this. Considering he is in his mid 60s, he clearly has compromised hearing an maybe that's why he doesnt do listening tests.

Do others think that audiophiles are wasting money on any higher end gear because of hearing loss with age?

And clearly Amir doesn’t need money. He lives in a $3million house!

Hans Van Maanen is a working physicist in fluid dynamics and a top published expert and designer in Audio with his own "temporal coherence" brand name speakers and amplifiers...

Who must we trust?

Someone who work with basic psycho-acoustic and design his audio components from it or Amir debunking "audiophiles" ?

As i already said, thanks to Amir for information debunking market specs of gear...But the bucks stop here... His bashing of audiophiles is not based on psycho-acoustic facts but on techno babble ideology ... Debunking is perhaps a field work because someone verify specs numbers thats all; but it is NOT SCIENCE NOR DESIGNING in audio it is only some technological tools choices applied for some NARROW goal ...

And bashing audiophiles is ridiculous enterprise... Why? Because there is too much difference between audiophiles themselves, and putting them in the same trash bin is RIDICULOUS... And bashing human hearing because of alleged limits in Hertz and Decibels is a common place argument ignoring the non linear nature and the time dependant dimension where the ears really work beating Fourier uncertainty principle; then bashing those who use their ears without even knowing psycho-acoustic basic facts it is ignorance and/or some  marketing propaganda for some goal of his own ...

Now look at the article for the context about these remarks by Van Maanen ...

«Feedback seems like a miracle cure for all shortcomings of audio equipment. Yet, in the ‘high-end’ audio community, many critics on feedback can be found. It is beyond discussion that the specifications of many semiconductor amplifiers are far superior to those of loudspeakers and vacuum tube amplifiers, yet this correlates not well with the perceived quality of the equipment. How come? And why is it possible to hear differences between amplifiers with distortions two orders of magnitude lower than the loudspeakers one needs to listen to these amplifiers? Are certain phenomena overlooked and, if so, what can we learn to improve the perceived quality of equipment? This paper analyses some pitfalls and parasitic
effects of feedback and gives directions for improvement of the perceived quality. This was confirmed by designing amplifiers, derived from this analysis, using unconventional lines in which listening by music experts was regarded as more important than measurement results. It showed that parasitic effects occur in amplifiers with global feedback, which are often disregarded, because these do not show up with the usual derivation of the equations for systems with feedback. These parasitic effects lead to the introduction of artefacts, which are
specific for systems with feedback. This is surprising, as the common idea is that feedback only suppresses undesired phenomena, but is an unambiguous result from the analysis, presented in this paper, which also shows that the commonly used equations for feedback are flawed. On top of this, several (underlying) assumptions about the properties of the amplifier are also incorrect.
Suppression of these parasitic effects requires linearization of the individual amplification stages as much as possible and by designing the amplifier in such a way that other properties are as close to the assumptions as possible, in combination with a constant, but moderate, feedback factor over the entire audio range. The testing of equipment using continuous sinewaves does often not reveal these parasitic effects as these only show up in the dynamic response of the amplifier to music-like signals. The simplistic approach that the sinewave response enables the prediction of the behaviour under all conditions ignores the conditions under which the Fourier theory may be applied and leads therefore to incorrect results and conclusions. Which is why there is a great need for well-defined dynamic test signals, but as long as these are not available, human hearing
remains for the time being the best piece of ‘measurement equipment’ which can be used...»

.............................

«The designer should realize that global feedback can only be applied to a limited extent and that the dynamic behaviour of the amplifier to music-like signals is (far) more important for the perceived quality than distortion figures, in line with the findings of refs. 3 and 4. These probably explain a part of the audible differences between amplifiers or other electronic audio equipment, which cannot be understood from the distortion figures and has given feedback a
bad name in certain high-end audio circles. Such artefacts are therefore hard, in many cases not at all, measurable using continuous sinewaves. As music is a textbook example of such a dynamic process, this is likely to be crucial for the determination of the perceived quality of an amplifier. So more complex test signals, which represent non-steady, multi-spectral conditions, as occur in music, are needed. As long as such test signals are not agreed on,
human hearing is still the best “measurement” instrument available.......<

...................................................................................................

It can be remarked that critical comments from high-end audio enthusiasts are often scornfully put aside by technology experts as “non-scientific” small talk from freaks who do not understand the theory. The author strongly disagrees with this view as too often critical remarks from people with “golden ears” did make sense, albeit that it was initially absolutely nunclear what the technical or scientific background was. Such remarks did help the development team to further improve the equipment, even though it would have been very hard to show the effect of the individual steps in a scientific way. But the progress over the years is beyond discussion...»

https://www.temporalcoherence.nl/cms/images/docs/FeedbackFlaws.pdf

As a guitarist myself, I think the fact that most professional guitarists run their instrument through a rack or pedalboard tuner tells you all you need to know about our so-called golden ears. Those of us with experience can tell that something is "off" fairly easily, but getting it to be "not off" by ear takes a little more fiddling and is subject to the bias of the strings surrounding them. So, scientific approaches like ASR's can get you in the ballpark a lot more efficiently than guessing.

Rational approach in audio private installation is related to electrical mechanical and ESPECIALLY acoustic embeddings controls...

Amir methods of measures CAN ONLY VERIFY GEAR SPECS as publised by the company and infirm it or confirm it... THATS ALL...

Amir cannot choose the gear for your needs and for his QUALITIES...

And if as a guitarist you dont trust your ears... What can i say ?😁😊

Myself i learned how to use my ears in 2 years experiments... Are they telling me always the truth ? no... Am i satisfied with my 600 bucks system ? Yes... It sound better Speakers/room and headphone that everything i listened to... and i can identify his FLAWS...

Is it perfect  then ? Not at all...But most people trust price tags not their ears... It is the reason why a pair of Magnepan in a living room can sound worst than my speakers box in a dedicated room... I know because i verified it...

How will it cost me to make my actual headphone system  almost perfect ?

15,000 bucks....Not a dollars more...

I know WHERE i go and WHERE i came from...

Dont trust anyone.... TRAIN your ears in acoustic...And READ articles and books... Not  only ASR forum   and audiogon forums ...

As a guitarist myself, I think the fact that most professional guitarists run their instrument through a rack or pedalboard tuner tells you all you need to know about our so-called golden ears. Those of us with experience can tell that something is "off" fairly easily, but getting it to be "not off" by ear takes a little more fiddling and is subject to the bias of the strings surrounding them. So, scientific approaches like ASR’s can get you in the ballpark a lot more efficiently than guessing.

@mahgister 

Then there is a high cost to pay if we TRUST the Fourier linear tools and if we work ONLY in the time independant and frequency domain... The price is we loose contact with the basic of human hearings...

I don't know why you keep bringing up Fourier transform.  Most of my tests don't involve any kind of fourier analysis.  Take the dashboard I post earlier for that Carver amplifier:

See those THD+N and SINAD numbers?  They are computed *without FFT*.  The analyzer simply filters out the 1 kHz tone and what is left is noise+distortion.  It then simply reports that sum energy of unwanted signal as a ratio to the test signal.  No FFT is needed or used.

The problem with that one number, as bad as it is in this case, is that it is not diagnostic.  So the analyzer in addition to that shows the fourier transform on top right.  Now we see the problems.  We have tons and tons of power supply noise and hum which better not be good in any audiophile's mind. 

We then look to the right and see copious amount of third harmonic distortion -- not the beloved 2nd harmonic people think tubes output. Using psychacoustics, we can overlay a graph on both the noise and distortion and assess audibility, again based on listening test research. 

Fourier transforms then are an invaluable diagnostic tool to assess audibility because much of our knowledge of psychacoustics is in frequency domain, not time.  In time domain, we are relative quite deaf.  This is by design.  When you listen to someone in your home, their voice gets bounced around the room, gets delayed (timing changes) plus attenuated and then mixes with the direct sound creating a "phase soup."  So the notion that time matters is non-sequitur in most part.

But again, a lot of our measurements are independent of any kind of Fourier transform.  This measurement that I post again has nothing to do with that:

Output power is varied and THD+N extracted per above explanation.  It shows that this amplifier is a distortion factory, overlaying its own signature on *everything* you listen to.  It is against the very word "high fidelity." 

You also keep saying we only use sine waves.  We do not and I already explain to you that 32-tone, multitone signal is just that, 32 tones and if you listen to it, it sounds like organ playing.  Its waveform in time domain is quite complex looking as well.

My jitter test also uses dual squarewaves which by definition have infinite number of sinewaves:

It looks like a single sine wave but it is not.  Everything above other than the 12 kHz spike is unwanted noise and jitter by the way.  Using psychoacoustics though, you arrive at what I say above, "not an audible concern."  Without the FFT you could do that analysis.

So really I would not keep repeating that the problem with measurements is some random claim about Fourier transform.  Plenty of tests don't use them.  And when we do, the FFT tells us the very thing we want to know: "how audible is that noise and distortion?"  The only people who don't want to see such an FFT is because they are afraid of the story they tell.  

They want to claim their gear sounds great despite the flaws found in measurements?  That is cool.  Just show a controlled test of half a dozen audiophiles with levels matched and blinded.  Post that and we can talk.  Don't keep writing essays.  Essays don't make music.  If ears are all that matters, then let's do an ear's only test.  Until then, all the rest of what you are quoting is hoped to confuse the regular reader who doesn't understand the topic, hoping to get you to forego proper proofs, that is, with ears only, equipment sounds better.