Can you get the grilles off and see if the midrange drivers are making any sound compared to the woofers or tweeters? Any level controls on the speaker? Is the speaker biamp/triamp-able and are those connections correct if so?

Pull the drivers in question out and check for voltage with a multi meter , that will tell you if it's crossovers or drivers . Music will have to be playing , make sure the two wires don't contact each other .