Active Vs. Passive

This has been discussed before. They are better because you remove the passive crossover. They are better because each amplifier drives one speaker driver over a narrow bandwidth (much easier than driving the entire 10Hz to 20 Khz range). The topology is very simple and offers better performance than the passive approach.

However, the above technical advantages do not count much as most people here like to be able to modify the sound through selection of a power amplifier.

I had Linn aktiv speakers then went back to passive and added a tube amp and pre. MUCH better. Aktiv marries the amp to the driver.

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.

All drivers are passive. If you do not use a passive crossover, you have an active speaker system, whether or not the amps are on board and whether or not the amps were furnished by the speaker manufacturer.

As an example, I would say that all single driver systems are active since they have nothing inserted between the driver and the amp, sometimes not even binding posts.