Bi-amping: active crossover

The ideal way to design a loudspeaker from the ground up is with a separate amplifier for each driver and an active crossover directing frequencies to each amp. And it is almost never done. And the few that have been designed like this aren't very well received. And there are a million opinions of why: Audiophiles like to choose their own amps, speakers that plug into the wall socket are not well liked, few have sounded that good, it's all or nothing in terms of sound; to name a few. Some people like to make their own active loudspeakers using their choice of amplifiers, electronic crossovers and drivers. This too is bi-amping (bi-channeling). To roll your own requires an electronic crossover. There have been many available over the years, and my favorite has always been John Curl's Symmetry crossover. But purely analog crossovers are rare today, and for good reason. What does one do with an electronic crossover that divides frequencies? How many loudspeakers come from the factory without a crossover to take advantage of them–even if DSP is included? I am sure there must be a few raw speakers, but I cannot think of even one. And so, using an electronic crossover to bi-channel a loudspeaker is a practice for hobbyists and do-it-yourselfers. For the most part. The idea is simple. In any multi-driver loudspeaker you must make sure the proper frequencies get to the appropriate driver: highs to the tweeter, lows to the woofer, middle frequencies to the midrange driver. In most speakers this is handled with a passive crossover built into the loudspeakers itself. Consisting of a collection of capacitors, resistors and coils of wire, passive crossovers are what define the sound of a loudspeaker–the tools of designers shaping sound. But there is a school of thought suggesting passive crossovers are too crude to make smooth sound. After all, combining two drivers into one seamless sound field is a serious challenge. An argument could be made that using modern active techniques that perhaps include DSP, would offer better performance than that of a handful of caps, resistors, and coils. Let's look at the pros and cons tomorrow.