Bad memory, but I think the 824 had paging tip/ring on black/slate. If we trust you had picked the correct pair, then you could run it to an amplified speaker.

There are people who would run the output of black/slate into an amplifier (Hi-Z if I am correct would be the 600 to 1000 ohm input) and then it goes out on a thick pair of wires with 25 volts AC or 70 volts AC and then you connect the common and the full wattage, half wattage, quarter wattage, etc as the second wire.

I use only amplified speakers. One pair of wire from the page tip/ring to the amplified speaker. Three other pairs carry -24 VDC from an inexpensive power supply to the two power terminals on the horn or ceiling speaker. The dial is adjustable from zero to 100% of volume.

The other paging pair is for controlling a relay that would switch from music playing to paging voice. You don't need that pair if you are not switching music to voice and back.

THE Bracha, old blond specialist in Rube Goldberg solutions.