XLR & Spades: Which is best? Pure copper, plated gold, plated rhodium or ?

I’m building interconnects and speaker wires and looking for XLR connectors and spades. If copper conductivity is at 100%, why would manufacturers plate copper with lower conductivity metals like gold, rhodium, brass, zinc, etc? Shouldn’t they only plate with 105% silver?


Material IACS (International Annealed Copper Standard)
Ranking Metal % Conductivity*
1 Silver (Pure) 105%
2 Copper 100%
3 Gold (Pure) 70%
4 Aluminum 61%
5 Brass 28%
6 Zinc 27%
7 Nickel 22%
8 Iron (Pure) 17%
9 Tin 15%
10 Phosphor Bronze 15%
11 Steel (Stainless included) 3-15%

For me base material matters the most, then coating mix.

I always find that pure copper as base material and silver/rhodium plating as coating works great.

What is best, depends on your system, whether you want to push things, mellow or refine.

My preference is for silver plated copper - it provides better transmisson/clarity and faster dynamics

The tarnish does not bother me because

  1. it only appears on the visible parts of the connector that is not forming the actual connection
  2. reseating will re-establish a perfect connection
  3. I do not clean my connectors because it makes no difference to the operaton or sound
  4. I do not use any type of jointng compound 

I am happy with my sound and see no advantage in obsessing over tarnish, because most of the connctors seldon tarnish in the atmosphere of my home

I have tried other types of metals and platings and prefer dynamics and clarity of the silver plated Copper

Regards - Steve