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

These are the five ways:

1) bar wire (either around the post or through the hole in the post)

2) spade lug

3) pin jack (solid metal pin at the end of the wire to go into that hole in the post)

4) banana jack

5) double banana jack (the positive and negative posts can be spaced apart by a standard distance such that the two banana jacks are fixed in a holder that has them spaced accordingly).

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..?