Actually JohnK, I don't think that is the case. I would assume that both sections are roughly 8 ohms (assuming that the mid/tweeter section and the woofer section have the same nominal impedence). This is because when the bridges are in use, thus creating a circuit that runs the parts in parallel (not a series), it is a 4 ohm speaker.
When you run two identical speakers (or anything else that adds resistance, for that matter) that are a certain impedence in parallel, you half the impedence. Thus, going the other way around (seperating the woofers from the mids/tweets), you would double the impedence.
