IM Distortion, Speakers and the Death of Science


One topic that often comes up is perception vs. measurements.

"If you can't measure it with common, existing measurements it isn't real."

This idea is and always will be flawed. Mind you, maybe what you perceive is not worth $1, but this is not how science works. I'm reminded of how many doctors and scientists fought against modernizing polio interventions, and how only recently did the treatment for stomach ulcers change radically due to the curiosity of a pair of forensic scientists.

Perception precedes measurement.  In between perception and measurement is (always) transference to visual data.  Lets take an example.

You are working on phone technology shortly after Bell invents the telephone. You hear one type of transducer sounds better than another.  Why is that?  Well, you have to figure out some way to see it (literally), via a scope, a charting pen, something that tells you in an objective way why they are different, that allows you to set a standard or goal and move towards it.

This person probably did not set out to measure all possible things. Maybe the first thing they decide to measure is distortion, or perhaps frequency response. After visualizing the raw data the scientist then has to decide what the units are, and how to express differences. Lets say it is distortion. In theory, there could have been a lot of different ways to measure distortion.  Such as Vrms - Vrms (expected) /Hz. Depending on the engineer's need at the time, that might have been a perfectly valid way to measure the output.

But here's the issue. This may work for this engineer solving this time, and we may even add it to the cannon of common measurements, but we are by no means done.

So, when exactly are we done?? At 1? 2? 5?  30?  The answer is we are not.  There are several common measurements for speakers for instance which I believe should be done more by reviewers:

- Compression
- Intermodulation ( IM ) Distortion
- Distortion

and yet, we do not. IM distortion is kind of interesting because I had heard about it before from M&K's literature, but it reappeared for me in the blog of Roger Russel ( http://www.roger-russell.com ) formerly from McIntosh. I can't find the blog post, but apparently they used IM distortion measurements to compare the audibility of woofer changes quite successfully.

Here's a great example of a new measurement being used and attributed to a sonic characteristic. Imagine the before and after.  Before using IM, maybe only distortion would have been used. They were of course measuring impedance and frequency response, and simple harmonic distortion, but Roger and his partner could hear something different not expressed in these measurements, so, they invent the use of it here. That invention is, in my mind, actual audio science.

The opposite of science would have been to say "frequency, impedance, and distortion" are the 3 characteristics which are audible, forever. Nelson pass working with the distortion profile, comparing the audible results and saying "this is an important feature" is also science. He's throwing out the normal distortion ratings and creating a whole new set of target behavior based on his experiments.  Given the market acceptance of his very expensive products I'd say he's been damn good at this.

What is my point to all of this?  Measurements in the consumer literature have become complacent. We've become far too willing to accept the limits of measurements from the 1980's and fail to develop new standard ways of testing. As a result of this we have devolved into camps who say that 1980's measures are all we need, those who eschew measurements and very little being done to show us new ways of looking at complex behaviors. Some areas where I believe measurements should be improved:

  • The effects of vibration on ss equipment
  • Capacitor technology
  • Interaction of linear amps with cables and speaker impedance.

We have become far too happy with this stale condition, and, for the consumers, science is dead.
erik_squires
This thread is an amazing one for me, for considerably greater reasons than the somewhat narrower field of hi-fidelity audio it began with.

May I first say that I truly appreciate the way you both think and process debate and argument - mahgister, and andy2 : ) - if you do not mind however, I would like to add to your already well-placed points, to say that it will not be possible to help heaudio123 understand the import of your arguments through the established points you have made so far.

You see, never mind all the advances that has been made with AI and everything else expected of it in the distant future, there is one thing, beyond imagination and inspiration, that separates human beings from every other living species, or intelligence, on earth. This is the ability to believe. Belief, and it’s lesser sibling of self-belief, is something beyond all understanding. In a world where the double helix has been reasonably well unravelled, where AI has taken over functions we could never have believed possible, where preventative measures for the avoidance of cancer is close, where human beings are able to survive for close to two continuous years in a steel tube called a submarine without needing to surface even once - the best minds on earth are no closer than they were a hundred years ago, to understanding the basis for what begins belief; how it becomes strong enough to give reason to keep living; how or why it evolves to create the wondrous built environment; and the circumstances under which it can suddenly collapse, to tragic consequences at times, or to remarkable beginning of even more powerful, new belief. This is truly what separates human existence from everything else. Mind you, this does not begin to touch on collective belief, which is another entirely profound discussion. So, never mind the fact that AI has not been able to replicate belief, the greatest human minds in the world have not even begun to marginally understand what it is, in relation to its mechanisms. This is something no robot, and certainly no AI will never be able to model, let alone replicate - not merely for the simple fact that the very definition of belief is that it CANNOT be replicated. So even if AI could replicate the conditions under which belief happens, evolves, changes, or ends, its very success will guarantee its failure. Belief is subject to nuance which cannot be predicted or anticipated.

And, if we can agree that self-belief is what drives the foundations of any invention, all original creativity, intelligence, and every moment of intangible human passion; then we could well say that AI in all its wonderful character and contribution, is woefully inadequate to even marginally dream of replacing any aspect of what matters most in human existence.

The truth of our human condition is that it is about change, evolution. And this moment of evolution is never scientific - a cell simply decides to break the rules to mutate - evolution is defined by accident, not methodology or preconception, the complete ‘science of known variables’ which I believe is what heaudio123 argues for. Never mind evolution, if too difficult to contemplate, the greatest experiences in our lives happen as result of the unexpected, of result of the accident. The most intelligent people on earth are the ones able to devise a life or work structure within which accidents can and must be allowed to happen, and be brought to awareness, for opportunity to be seen. it is impossible for every single variable surrounding even the smallest issue or ‘thing’ to be observed, collated, and factored for, in any ‘scientific’ method. This is the basic fact that governs ‘intuition’ - the ability to act in spite of not knowing every single fact - it is difficult to even grasp general facts about sound, impossible to fully comprehend the ridiculously complex act of hearing. 
So I do not think we are on entirely different sides of a raging river, to be able to understand that science and measurements only take us to a point, after which belief and intuition have to take over, often to hit and miss result, which is not a bad thing, since this structure itself has the unexpected built into it : )

i feel this is the crux of the discussion that has been running for five lovely pages now. And I love most that generally, every participant in the thread has been generally civil, and not too precious about themselves to still engage in some form of exchange. It is refreshing from so many other threads in audiogon that become personally insulting to individuals. Thanks so much for this :  ) - kevin
Post removed 
That andy2 and mahgister and you kevin repeatedly describe it purely as algorithmic, i.e. the same data will always result in the exactly same answer to n-decimal places, clearly communicates that your knowledge of AI is rudimentary at best and hence you type long posts on an audio forum site repeatedly that are fundamentally wrong as opposed to seeking out the knowledge that you lack.
I dont know for Andy2, but you cannot presume at all of what I understand and what not sorry..... I post to you a conference by Naftaly Tishby, that is not for the lay man and describe neural networks mathematical workings then i never describe the algorithm of neural networks like you said I did in misrepresenting me.... Have you read my posts?

Our biggest advantage is we achieved enough intelligence to enable formal communication
By the way this affirmation is totally ingenuous to say the least....

Read Ernst Cassirer a true scientist and philosopher to understand why it is naïve and totally superficial affirmation....After that you will understand the difference in concept "creation" in neural networks and true concepts creation....

You "believe" you are right, and hence, as opposed to learning, you keep repeating the same mistakes.
You are polite and thanks for that... But you are also arrogantly patronizing us about knowledge without knowing to who you talks... :) I give you some hint when I gives you names like Naftaly Tishby or Grothendieck…. Do you even know the names?
Post removed 
heaudio123"The crux of the discussion kevn (and andy2 and mahgister to some degree) is that you have no concept of how AI works, or can work, or how it is or can be implemented."

Actually what you’re remarks display and reveal and I will not quote them all here is that it is you that is unkowledgeable, uninformed, and inexperienced with AI and I know this because one of my companies is among the most advanced in the world in AI research much of which exceeds my ability to fully understand, assess, and comprehend however I have an extraordinary team of engineers, mathemeticians, and physicists who are capable of explaining to me the basic, fundamental, core aspects of the science which is how I know you are just wrong. You can dismiss, reject, and disqualify outright any thing you want without providing any valid substantiation, proof, or reference however such is not science you are acting on "feeling", intuition, and "gut" which is fine of course for discussion but that will not withstand examination, study, and scrutiny by those actually working in the field of science.