There's a good chance I'm gonna be buying a used pair of really nice components for cheap, however the seller is not including crossovers and said that these speakers should be run "actively" only anyway. Obviously that is an opinion but I don't understand the difference. Obtaining these crossovers would be hard and would probably end up costing me more then I'd be paying for the components.

I don't know anything about this, can someone enlighten me?

 

You need a 4 channel amp/2 2 channels to run active.

passive xovers(what he's not including are unpowered and split the freq. in the components.

Active is when filtering now occurs before amplification and needs an external power source. Active lets you determine the xover points rather using the factory determined points on the xover from the factory.

You can run a active setup with most of the highend headunits out there like the pioneer deh880-prs or use separate external xovers which are usually pretty big. You need an amp to power the tweets and another to power the mids. Active is better but more expensive.hope this makes sense.