Ceiling speaker has 3 wires
As it says in the PDf as well:

With power tabs for 3W and 6W.

And:

"Black:Com  Red:1.7KΩ  White:3.3KΩ"

Or drawn, its equivalent resistances are:







simulate this circuit &ndash; Schematic created using CircuitLab

You connect Black &amp; Red for 6W at 100V, Black &amp; White for 3W at 100V. Do NOT use the other wire in either case.