Hi everyone
Just joined Audiogon. I've been importing ATC to the US for almost 20 years in pro, just started in Hi FI and few years ago. Just saw this thread.
The real advantage of active is a practical one from the ATC engineering perspective.
The problems are
1) losses of a passive crossover, power losses of speaker wire, dampening factor issues with length of speaker wire, etc.
2) no precise phase adjustment of drivers in a passive crossover design.
3) as drivers heat up, values of the drivers change and the passive crossover sees a changing load, therefore changing crossover behavior
4) Two well designed 3 ch amps and power supplies within the speakers can be built for less than a large two channel amplifier with pretty chassis, case and feature set and all the connecting cable.
Brad Lunde
Lone Mountain Audio