There are active speakers, which include include at least one amplifier in the speaker, and speakers with active crossovers, which may or may not be active speakers.
The real advantages come from speakers that use active crossovers. That's when, as Shadorne describes, the crossover is inserted in the signal path before the amplifiers, so the amplifier sees only the simple impedance of the drivers in the assigned frequency range.
The best example of a speaker with an active crossover currently available is the Linkwitz Labs Orion, which calls for an amplifier channel for every driver. The Legacy Audio Helix is another example, but those are huge and expensive.
IMO, the advantages of active crossovers are real and audible. I'm less convinced active speakers, just because they have amps matched to the drivers, are such a big win.
The real advantages come from speakers that use active crossovers. That's when, as Shadorne describes, the crossover is inserted in the signal path before the amplifiers, so the amplifier sees only the simple impedance of the drivers in the assigned frequency range.
The best example of a speaker with an active crossover currently available is the Linkwitz Labs Orion, which calls for an amplifier channel for every driver. The Legacy Audio Helix is another example, but those are huge and expensive.
IMO, the advantages of active crossovers are real and audible. I'm less convinced active speakers, just because they have amps matched to the drivers, are such a big win.