Who knows why, but trust your ears.
If you can't tell the difference between cheap and expensive cables, your system isn't very resolving or you've got the speakers in the wrong place.
The molecular level explanation of "cable burn-in"
According to one cable seller
"The insulation (or dielectric) will absorb energy from the conductor when a current is flowing (i.e. when music is playing). This energy-absorption causes the dielectric's molecules to re-arrange themselves from a random order into a uniform order. When the molecules have been rearranged, the dielectric will absorb less energy & consequently cause less distortion."
So it’s the plastic polymer (as dielectric insulation) to undergo some sort of molecular rearrangements to minimize the distortion. Probably one of the greatest scientific discoveries ever!
“Many premium AC cords constrict or compress the audio transient as their characteristic impedance restricts the transient current.”
We all know impedance restricts current but how possibly “many” premium AC cords constrict/compress the audio transient (when not carrying audio signal)? Then again is it achieved by this molecular rearrangements of the cable insulation?
Unfortunately there are no measurement data or mathematical formulas to be found to back up this amazing scientific discovery. Simply “it happens”. So I came up with a formula for them.
∆E = P - SoT
∆E: energy absorbed by dielectric
P: energy (power) drawn from wall outlet
So : Smake Oile
T: Dielectric Transition Temperature