What Type/AWG Wire for Binding Post to Speaker Terminals?

Thinner cable give higher resistance to the driver, which raises the q and gives better damping of the driver (so it start and stop faster to the signal). So i see a logic in the thinking of Planet10. It's one of the many tricks in the book to make a certain type of speaker work, but it's not universal i think. And off course it only works on lower power systems (like most fullrange drivers are) as with higher power systems the cable will loose to much power from the amp or even burn due to overload (in extreme situtations).

But i use mostly just the same cable that i use as speaker cable, which is mostly 1.5mm stranded ofc copper wire (i buy it in large quantities) and count more on other factors for the bass response.
 
It was quite popular around the turn of the century with high[ish] sensitivity systems to use very narrow gauge speaker wire -30ga magnet wire, single strand, was a favourite, especially if you needed some series R in circuit to compensate for an amplifier output impedance / driver / alignment mismatch. A mite 'delicate', got hot, and while could help in that sense, the limited current-carrying capacity meant only higher sensitivity systems really needed apply. Although there are other effects, especially with slightly more modest system efficiencies. For e.g., you can get a scenario where the LF dynamic peaks are compressed / 'clipped' relative to the midrange / HF, with the effect of making them appear 'clearer'. Which in a sense, they are, releative to the LF.
 
I use silicone insulation high strand count RC drone battery/motor wires designed for high current. Typically 16ga internally offers very low resistance. Sometimes I double the wires. 259 strands and it’s super flexible and rated for 600v and won’t melt when soldering.

For example:
https://a.co/d/7oUlwhe

The low impedance matters for speakers and amps meant to work together to get the highest damping factor possible (aside from connecting the speaker directly to the amp terminals). You can measure this effect on damping factor / output impedance.