Step-up jazz 5 str Singles active Or Bartolini Mk II system... You can make them sound like just about anything. Call Geddy and see how he does it. I'm guessing an effects chain from hell.
My cab came with 15b's. The later ones may have15L's. Mine also came without the EV logo painted on the grill...it had a small logo plate glued to the bottom right corner witness by the yellow glue spot in the picture above.
Rocket surgeon doesn't know how to link it but look at Phil Jones cabs for the ultimate multi-small driver stuff. Highly praised by some heavy hitters. I never saw one but I don't rule anything out since I heard of resurrection.