Ok Paul,

let's say a 5m length of speaker cable. What ranges of inductance, capacitance and resistance would you say were required for a piece of speaker cable to be fit for the purpose of being connected to an 8 ohm loudspeaker?

Sadly, I don't think the Great Randi is examining the type of conductor in his particular 'challenge'. I believe the Monster Cable, and the Pear cable he'd like to be used are both made from copper.