Right, the conductors should be chosen for the desired BW, voltage drop over distance and why bi-wiring is a good plan due to the wide range variance between a woofer, tweeter.

Spacing opposing conductors causes both inductive and shunt capacitive inductance with increasing spacing, so is acting as a frequency shaping filter. You may like how it sounds and a tweak sometimes worth experimenting with [remember the 'trellis'/'railroad track' system to space up/spread out the speaker wire runs?], but's it's technically degrading the signal.

GM