Wayne Parham Messages: 18889 Registered: January 2001
Illuminati (33rd Degree)
In a loudspeaker, the crossover prevents adjacent subsystems from being on-line at the same time. When a driver is making sound, it is being presented as a load to the amplifier. But when it isn't, the impedance of that leg of the circuit is very high, approaching an open circuit. The idea is that only the driver playing presents a load, and in the overlap region where both adjacent subsystems are transitioning, they both present a partial, medium-impedance load. So the overall impedance curve is rarely flat, but it does approach the advertised impedance in most cases.