Total spade resembles roughly AWG10 and distance of 1/2". Copper 10AWG resistivity is about 0.001ohm per foot. 1/2" spade would have resistance of 0.000042 ohm. Silver spade would be 0.00004 ohm, while aluminum spade would be 0.00007 ohm. Such short connection would not make audible difference, at least from the point of conductivity. Yes, silver wires have reputation of sounding brighter, but here we're talking of 1/2" added silver on the top of 6ft of copper speaker wire.
Silver spades
I thought I would start a new discussion regarding the metallurgic composition of spades/bananas to ask a different question.
A friend suggested I look at WBT silver spades as an option for cable connectors with the hope of "opening" things up a bit.
I have found silver cabling a bit edgy but have not tried silver based connectors.
I wonder if anyone can comment on what silver based spades or bananas ( brand does not matter ) might add to a copper based cable.