Multi purpose 15" drivers


i'm am looking for a 15" High efficiency driver that will fit for 2 purposes.

Primarely they will be used for an OB speaker, with 2 drivers per speaker. with an active crossover(perhaps miniDSP) and the second purpose is PA horn sub.

The drivers i have looked at are the Fane Pro 15-600LF
I already know that they will fit the horn design that i have in mind very well.

My setup is also being used for parties, festival and stuff like that. so i have to be able to use the drivers for both thinks. because a student income doesn't really allow bying drivers for both purposes.

BUT my question is, do you think they will provide surfficient low end in a narrow open baffle.
I will be able to boost the low end a bit. but an xmax of 6.9mm might limit a bit.

If not, what driver would you recommend at the approcimately the same price?
I know i will require some equalisation with the driver i picked with its low QTS. my question is only if it has a high enough Xmax to handle being used in an OB.

I don't se why the Fane 15XB would alot different from the 15-600LF in an OB speaker. But it is WAY out of my pricerange anyways.

I know that Troels Gravesen have used an Eminence Delta II 2515 with succes. it has almost the same specs. but only 4.8mm Xmax.
Troels used them in a WIDE!(As in really WIDE(!) baffle) but he only used one driver per speaker. So figured i could use 2 drivers with a narrow baffle.

Already read the 2 articles by Martin King