Crossover for Fulton FMI 80s?

Recently got these for 10 bucks from goodwill. Not a ton of info but online it appears they have quite the following.

Seems like from what I read the low end blows but I have a sub already set up.

Currently have two Realistic Minimus 7s that I’m replacing with the Fulton (thinking about it). What should I set the crossover frequency for these speakers as I don’t quite understand that yet.

Any info and help would be appreciated!