No credit card local hookup
Under these conditions, the gold-tin bimetallic junction is subject to galvanic corrosion.
The controlling factors that remain are the speaker system impedance and the speaker wire resistance.
The loudspeaker circuit includes the connecting wire between the amplifier terminals and the speaker terminals, the amplifier internal impedance and the impedance of the speaker system.
There's also contact resistance at the connecting terminals of the amplifier and speaker system.
The connection between the power amplifier output terminals and speaker input terminals is almost always a pressure device of some sort.
It's unfortunate that these important connections are determined by to how tight you can turn a binding post or screwdriver or by the pressure of a spring which holds the speaker wire against the metal of the terminal.The metals that are forced against each other are often different.