You will save a LOT of money if you build your own speaker cables out of CAT 8 cable. They sound great.
15’ +; 15’ - is 30lf for one cable. x 2, you need 60lf
here’s 75 lf white Cat 8, oxygen free copper
cut the ends off, strip and twist/crimp the 8 copper strands, attach them to these banana, or spades
8 strands 26 awg is equal to 17 awg.
combined wire gauge calculator
8 strands 24 awg is equal to 15 awg