Paano ba setup ng speaker sa loob? 1st order or 2nd order ang high pass and low pass filter? Assuming your previous tweeter is 8ohms, tapos 1st order sya, around 9k ang crossover point, pag 2nd order sya, nasa 6khz ang crossover nya. So if you want to try to "attenuate" the output of the piezo, try putting the crossover point higher than 9k, lagay mo sa 12khz or so, mas hihina output nya without using resistors. Pero depending sa design ng crossover point ng woofer, pag 6incher sya, more or less crossover point nya nasa 3k-4k, so may butas ka from 4-9khz. You can't expect the woofer to produce frequencies beyond 4khz with ease kasi mas mabigat na yung cone nyan and malaki, thus hirap mag produce ng high frequencies, unless fullranger sya. Still the best solution is to let the piezo produce 6khz and up, then use an attenuation network.
