Biggest audio hoaxes


Often when people discuss audio, they talk about "snake oil" or "hoaxes."

It's pretty typical to use the term hoax as a tactic against another who disagrees with one, or holds an unusual opinion or vouches for something which has not been verified. That's not what I mean by a "hoax." 

By "hoax" I mean an audio product or claim which has been pretty definitively disproved. Maybe not to everyone's satisfaction, but to common consensus.

So -- with that definition of hoax in mind, what are some of the biggest audiophile hoaxes you've heard of?
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While there are sound differences that we do not know how or of what to measure, there are marketers who take advantage of "A little knowledge is a dangerous thing." One example is the issue of skin effect attenuating treble through speaker cables. It is true skin effect diminishes the effective cross sectional area of a conductor by driving high frequency AC towards the surface of the cable. The question is how much does it attenuate high frequencies. At 20 kHz the skin depth of copper is 0.47 mm; at this depth the current density is diminished by a factor of e. For solid 8 gauge copper wire a pair of 5 foot lengths of speaker cable has a DC resistance of 0.0064 Ohms. The skin effect cross sectional area can be closely approximated by multiplying the skin depth by the circumference of the wire. This increases the effective resistance to 0.011 Ohms. put this in series with a 4 Ohm speaker and 0.5 Ohms for the output transformer windings. Take the ratio of the resistance at 20 kHz for the full circuit to DC resistance and you get a figure of 0.99896. Keep in mind the thinner wires in the transformer and the speaker coils have a diameter much less than the skin depth making their difference inconsequential. The 0.99896 ratio works out to about 0.0009 db at a frequency no adult can hear.
When a cable manufacturer does litz or ribbon construction of cables and charges hundreds of dollars with the claim skin effect is a problem it has to be fraud and fraud is how many merchants who feel they need to do whatever it takes to maximize revenue or perish, that should be enough to assume many other explanations for special care such as doing something about copper grain boundaries acting like little semiconductor junctions which have threshold voltages that intermittently start and stop conducting when cheap antenna cable has no difficulty conducting micro-Volts are disprovable junk physics. The justification for this kind of behavior is "Let the buyer beware." but it is not reasonable to require every audiophile to have a PhD in physics (even though many pop culture simulacra who calumniate "PhD stands for piled higher and deeper" seem to deserve to be taken for their contempt for everything too intellectual for them.
I applied to work as a sales consultant in a franchise store selling audio and video equipment. The store holds classes to educate the sales people on the latest audio and video products. It turns out that one cable manufacturer that advertises itself as correcting the skin effect problem teaches the sales staff to lie to the customers about skin effect. They have a policy never to hire a trained physicist who might break out the graduate school texts and embarrass them. If the staff do not know they are practicing dishonesty there will be no problem. If the customer is happy because he experiences placebo effect after spending hundreds or even thousands of dollars on such cables the rationalization is no harm is done.
But to me the customer's human dignity has to come first; everyone deserves the truth. What I see can be the downfall of the high end audio industry one day. You can't get away with deception forever because it is only a matter to time before t catches up. That is why I design and build most of my own gear. There are a few manufacturers I know who are honest and earn their profit and living. I only hope they are not hurt when the $20,000 power cords and $27,000 speaker cables are exposed and things come crashing down.
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I was just saying the other day that people don't use the words simulacra and calumniate enough...
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