Every component in the ac- or signal path will need moore or less of a burn/break-in. some components in the signal-path like condencers might need a long period, while a powercable gets it`s massage a lot faster.
Speakercables are somewhere between, it will depend a lot on how much power you give them. And if they are worth your time. A poor sounding cable will stay poor. One hour of serious abuse is enough to get their character.