Help with Cetec Gauss compression drivers model 4060

Hey, I just got a pair of Cetec Gauss 4060 compression drivers with some unknown horns on them. These things are big and heavy!

I haven't put audio through them yet, but one reads 10.5 on the ohmmeter and the other reads only 4.9-5.0. Both say 16Ω. I suspect something is wrong with the one that reads 4.9 What would cause a compression driver to read low like that?

What would I have to do to test these if I don't have an extra crossover sitting around? I assume I shouldn't just put full-range audio through them, even at a low level.

Thanks!