Speaker cable

[Fandango Andy]

And that would be based on what? Expectation bias? Or sound, which we can measure.

The Last few responses seem to be about what can and cannot be measured. Ultimately music is about what is pleasing to the ear. This is a subjective thing. You cannot absolutely measure it scientifically. The best you can do is plot what people like, then measure a component to see if it matches those parameters.