I have not heard the difference myself, but from conversations with people I trust I would say the passive Klout. I can tell you that a passive Linn 2250, and especially a passive Chakra 2200, will sound much better than active LK 140's, and incidentally will be cheaper (especially once you add the cost of the active cards).
As someone familiar with making Linn speakers active (I have owned active Espeks with a Chakra 6100) I can say that they sound great. But once you get into active, it is hard to upgrade without a sizable expenditure. Also, the degree of improvement gained with going active depends on the complexity of the crossover networks involved, i.e., the improvement tends to be much greater as you go up the line in Linn speakers (eg, to a 242).
As someone familiar with making Linn speakers active (I have owned active Espeks with a Chakra 6100) I can say that they sound great. But once you get into active, it is hard to upgrade without a sizable expenditure. Also, the degree of improvement gained with going active depends on the complexity of the crossover networks involved, i.e., the improvement tends to be much greater as you go up the line in Linn speakers (eg, to a 242).