Ive found using mains cable that often the cable is directional.
After many years I have found the best solution is to use a multi strand copper cable for Bass (LF) and Silver coated (not tinned copper) copper cable for the treble (HF) a mix of the two can be used for Mid, if tri wiring or tweaking HF LS level.
I always construct the cable such that it is non directional to ensure the same cable impedance looking into the amp as looking out. This is an essential in my book to maximise the damping of the speaker coil back emf.
Suitable cable and terminations are available from CPC/Farnell. Bass @ approx £40 and treble for approx £20 (+vat) in lengths of 30M.
My golden rule is always keep LS cable as short as possible.
I have my Ncores behind my LS with 10" cables The N cores are fed balanced over 13M from my equipment rack.
Technics 1200 tweaked,Ianmac Bearing,DACT DIY Phono Pre, Belcanto CD-2, Engineered Switzerland DIY Renderer, Benchmark DAC2, Hypex NCore, ATC SCM40
2nd system --Engineered Switzerland DIY streamer, Sony CDP11,Topping D50 DAC, Hypex NCore. Kef 1point2 speakers. Ianmac Filters