"Simple: it's the opposite of a passive system.
In a passive hi-fi system the job of dividing up music's high, middle and low frequencies so that they end up at the appropriate drive units in the loudspeaker is performed by an ..........................
..............Bi-Wiring (NOT Active)
"Why does Naim not agree with bi-wiring and tri-wiring passive loudspeakers?
It's true that we are not great fans of multi-wiring passive loudspeakers in accordance with current vogue. Our belief is that if the crossover has been correctly designed, a single run of cable between amplifier and loudspeaker offers the best sound, as well as making it easier for the amplifier to drive safely.
Obviously, if the speaker crossover has been deliberately designed to sound better when bi- or tri-wired, then it quite possibly will; but that's not to say that it wouldn't sound better overall if it were designed for single wiring in the first place, as our speakers are."
In Addition:-
No Naim speaker is suitable for bi-wiring"