Wayne Parham Messages: 18748 Registered: January 2001
Illuminati (33rd Degree)
This was one of the things discussed in the π crossover document, along with several solutions for it. It was also one of the main topics of discussion in the "Crossover Electronics 101" seminar at the Midwest Audiofest. Not only did we show it as a response curve - both modeled and measured - but we also listened to the sound of these effects. It is clearly audible.
There are lots of solutions that a person can choose, but a single capacitor is not one of the better ones. It either creates an audible peak or it allows excessive out-of-band energy. Caps that are small enough to actually act as a crossover make a big response peak. And those that are large enough to shift the peak down out of the passband allow too much energy to be developed down low.
So you are right on the money here. Best to analyze the system in Spice to find out what's really going on.