I am constructing a crossover with frequency of 100-200Hz, and it is for a subwoofer. First, i'm not sure what frequency works best. Secondly, if i understand crossovers correctly, an active crossover uses components like op amps and others. Where, on the other hand a passive crossover just uses inductance. My question is this, is the sound quality the same of both? Or are there substantial losses in quality in the passive crossover. Because, from my point of view the passive is much much, simpler to build.