Regarding the use of external, active crossovers with consumer speakers; I'd suggest caution. Remember that crossover slopes are additive; that is, they can be superimposed on one another. For instance, say you've got a loudspeaker that's designed to sum flat (frequency-wise) with a second-order (12dB/octave) crossover. If you were to insert and active crossover using the same frequency and another second-order slope, you'd esseentially end up with a fourth-order (24dB/octave) crossover and a big frequency dip at the crossover frequency.

Active crossovers are usually used for pro applications. In most cases, they replace parts of the passive crossover- that is, pro speakers designed to use an active crossover will have few, if any, high-level components (coils, caps, etc.) built into them and they cannot function properly without the external crossover. Some consumer speakers are designed to use active crossovers, and we'll see more in the future; but using one on a speaker designed to operate passively is, I'd argue, a mistake.

[This message has been edited by gw10nt (edited July 09, 2003).]