Active crossover vs passive crossover? Need HELP!!!!!

[Starbucks]

Hello
I'm only in year 12 at school and i'm having some trouble with one of my assesment tasks. Sad as it is, i've spent hours researching trying to find out exactly how active crossover systems work. You all seem to have a very good idea about what your talking about so i was wondering if you could give me a hand. All the sites i've visited so far only say that a
bi-amp sytem uses active crossover and it uses a high pass filter and a low pass filter to divide the frequencies for the tweeter and woofer. I have been informed that active crossover uses diodes and transistors to work but i have been unable to fully comprehend how. Could you please help explain this to me if you can. I find nothing more infuriating than being unable to understand something. I'll fully understand of course if you think this is a waste of your time but please help me out. I'm at wits end.

 

[blueeyesm]

Q: What's the difference between passive and active crossovers?

A: There are two types of crossovers — "passive" and "active" (also referred to as "electronic"). A passive crossover is basically a capacitor or coil installed on the speaker leads between an amplifier and a speaker. It sets up a roadblock to stop certain frequencies from reaching the speakers. Passive crossovers are relatively inexpensive and easy to install. Their primary disadvantage is that they tend to make your overall system slightly inefficient because they filter out signals that have already been amplified.

Your system will perform better and be more efficient using an electronic crossover, especially if you're running multiple amps. An electronic crossover is installed between your receiver or equalizer and your amplifiers. It filters and directs the frequency bands in the low level signal before they reach the amplifiers.

Active crossovers are usually adjustable (you can select the crossover points) and often have other features like bass boost circuits and phase switches for subwoofers. Another bonus when using an electronic crossover is that you can independently control the relative volume of different types of speakers.

http/www.crutchfieldadvisor.com/ISEO-rgbtcspd/learningcenter/car/crossovers_faq.html

and

http/www.snippets.org/filters/crossover.htm