Sorry, just saw this. The Calibres can be ordered as a passive speaker or in the XD version with internal amplifiers. With the XD'S you can run them passive with an external amp, fully active with the internal amps powering everything or bi amped with the internal amps powering the bass drivers and an external amp powering the mid woofer and ribbon tweeter. I'm doing the latter but you can run them full range with just a pre amp if you want.
I promise you they will not run out of power but will sound great at any level.