Logitech Z-4 speakers and Mac setup?

I have an Imac and just purchased some z-4 external speakers. How do I connect these to my Mac? I can't get any sound yet. I checked the "sound" settings on my Mac. I don't see my speakers in the "output" section of sound?

Do I need additional software etc for these to work? It looks like my Mac doesn't recognize the speakers?

youd connect them just like any other speaker set.

do you have them plugged into the correct port? one is an input and the other is an output.

you dont need any special software or programs.

Working now

Very strange but they started working. Everything is fine now thanks.