obobskivich
Headphoneus Supremus
Oh really? According to you, an active crossover "can be based on passive...speakers"? Right, you know what you are talking about...
Sure, with an outboard crossover. Here's an example:
http://www.accuphase.com/model/df-55.html (if you want studio-craft devices, look at dbx, Behringer, and BBE. They're labeled "speaker management" or "crossover" (like this: http://www.bbesound.com/products/speaker-management/ds48.aspx)). If you're only trying to tie subs to speakers, there's bass management hardware as well - like the Velodyne SMS-1. Finally, there's fully automated solutions from DEQX and Trinnov (that can do either bass management integration, or full management).
Each driver (or set of drivers) get their own amp channel and the xover breaks it upstream. There's even DIY designs available for this; I know Pete Millett was experimenting with an all tubed design (schematics are available), and MiniDSP is a popular choice for hobbyists as well (fully customizable).
Multi-amplification is not the sole domain of powered speakers. Like I said, there's no need to fight about this back and forth...:rolleyes: