Do speaker cables need a burn in period?

There is no way that speaker cables need a burn in. Anyone who says that they do is out of their mind. All that a conductor does is allow a current path from point A to point B. The distance between the negative and positive conductors and the gauge of the cable does make a huge difference. The type of materials as in the conductor, how they are wound and insulator make a difference. As frequencies go through the speaker cable you have natural capacitive and Inductive reactance occurring as frequencies rise and fall from as they travel through the cable. The most noticeable difference in higher powered systems would be a current capability of the speaker wire. The higher the frequency rises the more frequency radiation off the speaker cable will happen. A properly wound / spaced cable may sound slightly brighter because it will pass higher frequencies better. Since there are no active components in a Speaker Cable there is nothing to burn in. It is simply an electrical conductor. Most people could not tell the sound difference from 10 Gauge speaker cable from Home Depot from a cable costing thousands from some esoteric speaker cable manufacturer.  You would be best to concentrate your efforts on the active components of the system. Speakers, Pre-amp, Power Amp or receiver.  Don't take anyone's word for it. Many people are out to make a fast buck. Go listen and decide if you can tell a difference and if the cost is worth the price mark up.

There is no way that speaker cables need a burn in. Anyone who says that they do is out of their mind. All that a conductor does is allow a current path from point A to point B. The distance between the negative and positive conductors and the gauge of the cable does make a huge difference. The type of materials as in the conductor, how they are wound and insulator make a difference. As frequencies go through the speaker cable you have natural capacitive and Inductive reactance occurring as frequencies rise and fall from as they travel through the cable. The most noticeable difference in higher powered systems would be a current capability of the speaker wire. The higher the frequency rises the more frequency radiation off the speaker cable will happen. A properly wound / spaced cable may sound slightly brighter because it will pass higher frequencies better. Since there are no active components in a Speaker Cable there is nothing to burn in. It is simply an electrical conductor. Most people could not tell the sound difference from 10 Gauge speaker cable from Home Depot from a cable costing thousands from some esoteric speaker cable manufacturer.  You would be best to concentrate your efforts on the active components of the system. Speakers, Pre-amp, Power Amp or receiver.  Don't take anyone's word for it. Many people are out to make a fast buck. Go listen and decide if you can tell a difference and if the cost is worth the price mark up.

Emphatic fellow, wouldn't one say?

Wha, wha, what?  🤔🔌🐈🐍💩

Cables are definitely worth the asking coins.  Cables are like car tires.  A car needs a good set of tires for optimal performance.