Is speaker cable burn in real or just snake oil?
Well, it is relative. And what do you desire.
If you mean sending energy through it, yes, that is a real job of a cable.
You cannot pass energy through snake oil. But it may be flammable.
On the other hand, if you mean preconditioning wire in an audio system like speaker cables and expect some changes in sonic characteristics, it depends on the amount of energy. At some point it will start melting the insulation and may be audibly explode?
Or, do you mean changing the sound in a small matter for better or worse? That is nonsense, no snakes involved or harmed.
