What is a crossover? Why would I need one?
A crossover is a device which filters signals based on frequency. A high pass crossover is a filter which allows frequencies above a certain point to pass unfiltered; those below that same point still get through, but are attenuated according to the crossover slope. A low pass crossover is just the opposite: the lows pass through, but the highs are attenuated. A band pass crossover is a filter that allows a certain range of frequencies to pass through while attenuating those above and below that range. There are passive crossovers, which are collections of purely passive (non-powered) devices – mainly capacitors and inductors and sometimes resistors. There are also active crossovers which are powered electrical devices. Passive crossovers are typically placed between the amplifier and the speakers, while active crossovers are typically placed between the head unit and the amplifier. There are a few passive crossovers on the market which are intended for pre-amp use (between the head un
