Do pure copper banana plugs make a difference in the quality of the speaker sound.

Free yourselves from the neurotic obsession with conductor materials! 

I've used a couple of different connectors

For spade connectors I use Furez silver plated copper - they have proven t be the best sounding spade connectors I have tried

For Bananas, Furez also produces a nice Silver Plated Banana
- BUT the Bananas plug I now use is from KLE Innovations - it is exceptional and are great for installing jumpers on Bi-wireable speakers

I found that silver plated copper provides the best details and clarity and if the silver plate does tarnish then reseating the plug will effectively clean the tarnish at the point of contact (if there is any)

The black "Tarnish" on silver is the silver reating with the Sulpher in the air to produce silver sulphide, which actually conducts electricity, unlike the tarnish on bare copper, which MUST be cleaned/removed.

I did use the more affordable gold plated brass and Berylliam Copper type of banana for a while, but the silver plated copper are better - to these ears anyway

I use silver plated copper Mains connectors on my mains cables

And the RCA's from KLE Innovations are the best RCA's I have tried to date

Hope that helps - Steve

Thanks for your informative reply.

I will say that what does NOT work is hard metals, like rhodium, or solid brass.

You want your plugs to be soft and non-tarnishing, preferably with a spring to them, like banana plugs have or the spring loaded WBT spades.

Anything hard like rhodium or gold over pot metal (like the Monster screw on spades) is never going to have a tight fit, especially when used in nickel plated speaker terminals.

Like the man said, don't be neurotic.  Use whatever connector comes on the end of the cable.  

Oh, and if you think you're gonna save some money putting your own on the end of some wire and do just as good, you're not. So that's another one you can not worry about.