John Dunlavy On "Cable Nonsense"

The community should understand the difference between "statistical" and "practical" significance. Consider the following example.

Through omniscience, we know that:

Car A gets 20.1 mpg.
Car B gets 20.2 mpg.

Obviously, the TRUE difference between the fuel efficiency of cars A & B is 0.1 mpg. Sampling a sufficiently large sample size of cars A & B, we would be able to detect a "statistically significant difference" between the mpg for the two cars. But once we do detect a "statistically significant" difference, what does it mean?

In this case, it means precious little in terms of "practical significance." That is, how much is a 0.1 mpg difference really worth in the real world? Not much! And certainly, consumers would not be willing to pay a significant amount of money for such a trivial difference in fuel economy.

Now to come back to the issue at hand in this thread, let's assume that it really is possible to find a "statistically significant" difference in the sound of cables (this is a leap of faith given JD's blind testing results, but references to a "J. Peter Moncrieff of IAR" keep cropping up and I'll accept this single result as valid). The central question becomes -- Is this "statistically significant" difference a "practically significant" difference. I would argue that it is not, especially in the context of the obscene prices charged by high-end cable manufacturers.

Understand that when statistical testing ends in non-significant results or mixed resutls (i.e., sometimes significant, sometimes non-significant) the most frequent reason is that the difference that is being observed (i.e., the "effect size") is so small. I suspect that it is the case here. Any true differences in the sounds of cables are so subtle and small that they cannot be detected with any consistency if at all. So a rational person must ask, is it really worth thousands of dollars to achieve such a subtle and small difference? Only the individual can answer that question for themselves. But as far as the audiophile cable manufacturers' claims of vast differences in and superiority of sound, I maintain that they are hooey at best.

In a recent post, Detlof mentioned that he tailored his system to "his ears", i.e. the kind of sound reproduction HE likes. I subscribe to this view and, thereby, my opinion on equip is tainted with my preferences in musical reproduction.

Cables are part of the system and, assuming they contribute a sonic signature (i.e. different cables can make the system sound different), "that cable is best that supports/enhances MY sound the best".

In this respect, I also subscribe to Doc's view above, in that "vast improvements in sound (can) be hooey". Only vast if enhancing YOUR sound. If not, hooey (despite positive audiophile adjectives...).

Can't we say that cables are both a personal and system dependant affair?

Docwarnock - Some people view audio gear as a hobby or an obsession like modifying cards. A guy who puts a new $1,000 exhaust in his car to gain 1/10th of a second in the quarter mile (a statistically insignificant gain in power, according to you) might look crazy to some. A guy who puts a new $1,000 power cord to gain 1dB of improvement in some area might also look crazy. But both guys are trying to make their gear the best it can be, not fit into the pefectly average category.

Greg makes a good point, if someone moves a throw pillow to a different chair in my house, I would notice it, and say that it was a significant change (positive, or negative). If someone comes to my house, and is not very familiar with it , that person would not perceive anything wrong, or different. It is my complete familiarity with my room arranements that allows me to notice significant differences in what might be a subtle difference to someone else. Same with cables and systems. These tests don't prove or disprove much of anything, but if one person can hear differences 100% of the time,then anyone saying there is no difference is a fool.

Jay, I think that you may misunderstand what I said. In your example, the gain in power may be real and thereby detectable as "statistically significant". But it is the practical significance of such a trivial gain that is in question. And I agree with you that people who are willing to go to such great lengths, both financially and otherwise, to exact such trivial differences do indeed "look crazy" (your words), or at least a little neurotic.