Fr = 1 / 2 * Pi * √LC

So what you'll find is that there is a frequency where the impedance of the system drops to zero with the coils installed. It also means that the current through the tweeter approaches infinity, so naturally you'll expect a puff of smoke to accompany this frequency. Even if it's outside of the audio bandwidth by a considerable margin, I'd still discourage use of coils across this tweeter. Amplifier oscillation or the impulse of power-on or power-off surges could very well excite the system into resonance and make a nice demonstration of pyrotechnics for you.