what speaker cable do you use on the Evolution Acoustics MM3 speakers or Harbeth speakers.

Fidelis AV which is the national distributor for Harbeth uses Tellurium Q Silver Diamond speaker cable.

Clear Day Cables Shotgun speaker cables with my MM3’s. Great cables and better seller.

Cerious technologies Graphene extreme speaker cables with Harbeth are exceptional.

With Harbeth, you'll definitely not want warm leaning cables.  Silver cables could be a possibility, but sometimes they're a bit lean.  For my P3ESR, after a few iterations, I ended up sticking with Furutech cables and they're a very synergistic match.  I went DIY, with the Alpha-S14 cable and terminated with Furutech rhodium banana plugs crimped with WBT sleeves.  This is their alpha OCC wire, and essentially the same as the Speaker Reference III line, but smaller gauge.  Not a warm cable, maybe slightly sweet through the mids (like Harbeths as well), and plenty of detail and openness. For this particular system, the price and performance was right.