Because tweeters are very fragile and we are talking about using a few hundred watts of amplifier power.mstechca said:I don't get it. Why should a speaker circuit be so complex?
A simple series capacitor attenuates low frequencies at the rate of only 6dB per octave. Therefore for the 3kHz crossover frequency, the power to the tweeter would be 1/4 at 1500 Hz which would probably blow the tweeter. This speaker uses a 3rd-order filter for the tweeter and if its values are correct, the power to the tweeter at 1500Hz would be only 1/64th.
The design of a speaker crossover that uses a capacitor or two and an inductor is complex. The series capacitor and inductor resonate, and if an incorrect source or load impedance is used, at resonance there would be either a notch or a peak in the tweeter's response.
If the impedance of the tweeter is much too high which happens if it blows, then the series capacitor and inductor to ground resonate with a dead short to ground.