Engineering White Papers suggest that only A/B comparison..

[skeptic]

"The article suggest that:"Taken [cable's effects] altogether (ie., inductance, resistance, interference, skin effect, capacitance), these ugly realities introduce various dynamic and time-related forms of signal distortion which are very difficult to quantify with simple sine-wave measurements. "

The mathematics of waveform analysis have been known since Laplace and Fourier well over a hundred years ago. They will never become obsolete because they are correct. The people who promote certain types of audio equipment including special cables have negated the value of these analyses but offer none of their own as a substitute.

I think it's interesting that we can analyze the waveforms of millions of chemicals using infrared spectroscopy and identify virtually every single one using this method, we can set standards for the waveforms for broadcast and reception of radio signals up into the microwave region, we can analyze the waveforms of light and x-rays from outer space so faint they couldn't even be detected a few decades ago and deduce the structure of galaxies billions of lightyears away, we can analyze other radio waves and deduce the structure of subatomic particles but we cannot measure or understand the waveforms of audible distortion in speaker wires. Doesn't sound plausible to me.

As for DBTs, what other method do those who dismiss well run experiments to test whether a difference can be detected or is the result of random guessing offer as a substitute?

It seems to me all I hear are anecdotes about how great some product or other sounds and half baked theories from squirrel brained wanabee scientists about obscure theories of fermi velocity of electrons, grain boundries in metals, strand jumping, but no hard evidence of any kind whatsoever. They may not have anything to convince a scientist or engineer but then most of the market for their products are not scientists or engineers.

[Tony_Montana]

I think it's interesting that we can analyze the waveforms of millions of chemicals using infrared spectroscopy and identify virtually every single one using this method, we can set standards for the waveforms for broadcast and reception of radio signals up into the microwave region, we can analyze the waveforms of light and x-rays from outer space so faint they couldn't even be detected a few decades ago and deduce the structure of galaxies billions of lightyears away, but we cannot measure or understand the waveforms of audible distortion in speaker wires. Doesn't sound plausible to me.

I agree with your statement 100%. But the article said "with simple sine-wave measurements"...such as from an oscilloscope. Harmonic structure of signal can not be analyzed with such a instrument. But it can be analyzed with an Spectrum Analyzer

In a sighted listening, no matter how rapidly you switch, it is still has no meaning as it is still uncontrolled for bias.

There are too much generazalation in that statement. [IMO] The beauty of rapid switching is that it can be repeated as many times as needed easily (with just using a thump) until a person is satisfied that A sound better than B. So even if the person is slightly biased toward B because it is fancier, then repeated testing will either confirm his/her biasing or destroy it. There are no two way about it

What am I comparing? Compare what was played in the past with what is playing now? No, you cannot compare a running tape and have any meaning.

Then how would one conduct rapid switching if not a running tape?

[skeptic]

"I agree with your statement 100%. But the article said "with simple sine-wave measurements"...such as from an oscilloscope. Harmonic structure of signal can not be analyzed with such a instrument. But it can be analyzed with an Spectrum Analyzer "

Then you disagree with Fourier. Fourier says that even non periodic waveforms can be described as the sum of an infinite number of sine waves of different amplitudes. A spectrum analyzer only indictes the relative amplitude of those sine waves within a given time window and within a given range which for audio is 20 hz to 20 khz. The specific equation which takes a waveform from the time domain to the frequency domain is f(jw)= integral from 0 to infinity of f(t)e exponent jwt times dt where w (omega) is 2 pi times the frequency and e is the base of natural logarithms. dt of course is an infinitesmal unit of elapsed time. The inverse function which converts from the frequency domain back to the time domain is similar. You will find it in any book on second year calculus or a beginning book on linear systems analysis. In fact it is the starting point and foundation for this kind of analysis.

BTW, a real spectrum analyzer doesn't have a bar graph type display of the type that you see in consumer units, it has a crt or other display like an oscilloscope and displays amplitude versus frequency continuously. It also uses a sweep frequency generator, not a pink or white noise generator as the test input. The sweep of the oscilloscope horizontal (x) axis trace is synched to the sweep frequency generator while the calibrated microphone of course provides the drive for the vertical (y) axis.