Just do a quick measurement of the Nordost speaker cable:
Blue heaven:
Freq = 1Khz , L=3.3uH , R=0.06 Ohm , when speaker wire coil together and measured as L=11uH , R=0.06 Ohm
Heimdall:
freq = 1 Khz, L=3.55uH , R=0.04 Ohm
From this measurement , it can be concluded that higher tier cable of same brand the resistance will be lower, and don't laugh at some user that use clip to float the cable in air, as by doing so they just reduce the self inductance of the speaker cable. But actually all u need to do is just lay the cable straight so that it does not cross and the cable inductance will reduced. Also as the cable resistance is extremely low, it makes sense to have the speaker contact clean properly and remove the oxidation so u get the best low resistance contact.