just to summarize...here are the 2242H and the 18LW2400
normalized inductance (le/re) is 0.27 for both drivers.
2242 has copper ring *in* the gap
2400 has 3 rings, not sure of specific positions
top plot is 2242. impedance is tough to see. log scale. 3.1, 10, 31, 100 ohm markers. impedance swings up over 100 ohms by 20khz.
bottom plot is 2400. impedance swings up to only 75 ohms by 20khz and the curve appears more linear, suggesting better inductance control.
sensitivity on the jbl is about a db higher in exchange for slightly beefier coil and higher power handling on the 2400.
both have similar upper end resonance and rolloff.
tough to ding the 2242, as I've never heard a single person mention that they were unhappy with its performance in its target range.
that said, new, the 2242 is about 2.5x the cost of the 2400 and 18sounds is a solid company.
they are soooo close it would be tough to say which would come out on top, if either, in a very controlled listening test...so i suppose that is what it would have to come down to. on paper, the 2400 appears to me to be the slightly better driver.
and i can't believe that i just wrote that.