crossover points


2001-09-17 9:27 pm
This is something of a newbie question that I still don't have a good grasp on. When you are deciding on a two or three way speaker, how do you decide where you want your crossover points to be and the slope of the crossover? Do you just make an educated guess based on the specs of the drivers and then tweak from there?
Actually, it's worse than that. You'd like to avoid having crossover points in the midrange, particularly in the range of the human voice.
Clearly, it's an impossible task, so you make compromises.
Obviously, the starting point must be the frequency ranges of the various drivers. For mids and tweeters, you'd like to stay as far away as possible from their resonant frequencies. Try, whenever possible, to allow at least one octave before the rolloff of the driver, and/or its resonant frequency.
Other than that, it's just a lot of cut and try. An active crossover with selectable crossover points and level controls can make the process go much faster, even if you intend to build a passive crossover. At least that way, you can get a clear idea of the tonality of the drivers over an octave or two of prospective crossover range. It's startling how much the 'sound' of the speaker changes with just a few steps in crossover point.