Why are these called 5 way binding posts? I count four!

The term "5-way binding post" is actually a bit of a misnomer, as there are typically only four ways to connect speaker wire to these types of posts. The five-way designation comes from the fact that these binding posts have five individual components, which are:

1. The post itself, which is typically a metal shaft that is screwed into the amplifier or speaker cabinet.
2. A threaded collar or nut that secures the post in place.
3. A plastic or metal insulator that prevents the post from coming into contact with the metal chassis or cabinet.
4. A hole or slot in the post that allows you to insert a bare wire or a spade connector.
5. A hole or threaded insert in the side of the post that allows you to insert a banana plug.

So, to summarize, the five components of a 5-way binding post are the post itself, the threaded collar or nut, the insulator, the wire/slot, and the banana plug hole/threaded insert. However, there are only four ways to connect speaker wire to these posts: bare wire, spade connectors, banana plugs, and pin connectors (although the latter are less common).

4 ways to the speakers, one way to the amplifier..?

5 way boggles my mind.

DeKay

It was explained to me many years ago by an amp manufacturer, whom I forget, because you were able to use a spade ( or loop/hole ) to the shaft, and a banana plug, simultaneously........Is this true ? I am only repeating what I heard. MrD.

I'd call it 3 way, bare wire, (in a hole or wrapped around) are the same damn thing really.