Spades vs. Banana plugs ??

By adding bananas or spades you are doubling the contact issues: between either and the cable and between either and the speaker plug. Way better to go bare wire into the speaker using something like Mad Scientist’s contact enhancer. Spades get tightened and then loosen and bananas need good crimping.

Naked wire, neither spades nor bananas add anything

In my experience mixing metals and introducing additional metal mass are both detrimental to speaker connections. Bare wires are best followed by minimum weight pure copper spades lest you use silver wires