Passive crossover design

There are all kinds of textbook crossover design tools on the web that will show you what component values are needed to generate your crossover. Designing a passive crossover that sounds good goes way beyond a basic crossover though, and that is because the acoustic result is the product of the output from the crossover and the speakers they are attached to which usually have a response that is far from textbook. And you may also want to consider the polar response(horizontal coverage) you want to achieve when selecting a crossover frequency, the response of low frequency drivers narrows to a beam in front of the driver at pretty low frequencies, a 15" beams above 1khz for example, a 12" at 1.2khz and that is why most PA speakers systems have relatively low crossover frequencies. If you don't care at all about off axis coverage then use whatever crossover frequency you want.. higher is better for high frequency drivers, I'm trying to make you aware of of the tradeoff you are making.