The size of a driver bears no relation to the sound it makes. There are 10's that go lower than 15's, there are 12's that go higher than 10's. Then throw in the design of the cab to get an even wider range of frequencies.
Barefaced make exceedingly good cabs. I see you've already been speaking to Alex. I'd believe him. He operates a 30 day return, so if he gives bad advice, just to sell a cab, he knows it'll be coming straight back. He was spot on when I spoke to them about my cabs.