Audiophile friends
Fueling powerful speakers (300 W room, for example) forces according to the distance, a good cable of twisted copper and good section, such as Ci.
Never go below 2.5 mm and up to 10 or 12 m, 4 mm section is perfect, beyond the 6 mm would be required.
A rule to know: a big section enhanced bass (recommended on longer) but attenuates acute (where 2.5 mm if the length is used there).
Good recommendable product.