Less talk the science a bit. If you are passing high current to your speakers you need the wire to have the capacity. This means lower gauge, braided. Yes if you try telephone wire, you will limit the current and is going to sound like crap, filtered. Current travels on the wire surface, that’s why you want to use branded, it has more surface area for the same gauge. Go with fatter wire ( lower gauge). I bought 10 awg braided copper speaker wire for $1/ foot at Lowe’s on a 100 foot spool. It will carry considerable more current than 14 gauge, thus less limiting than 14 gauge. I did try a comparison with borrowed high price specialty speaker cables and found no difference. You will find that the recording industry does not buy in to the boutique speaker cable fad. The limiting point on your cables will be the connects, so the argument to not use banana plugs is real, they offer very poor high current pass. Spade plugs are better, or copper wire through the binding posts, tight.