An excellent place to start is by reading the comments offered in the following thread by the noted designer Steve McCormack (Stevemcx), especially if you want to consider passive biamping (without an external crossover):
http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1185660642
Regards,
-- Al
http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1185660642
Regards,
-- Al