BUMP

Ok. found the post.

If there is something in line with the positive line to the tweeter it will be a small filter cap.

This is used to provide a shallow 6db filter for the tweeter to roll off low freqneucy's.

In the simplest form you can just use a cap in series with the positive line (like i think in your case). More advanced set-ups feature steeper slopes and other features such as phase correction.
Most boxed type crossovers feature 12db, 18db or 24db slopes.

GENERALLY speaking the more expensive the speaker the more advanced the crossover and USUALLY the steeper the slope.

tyhere are exceptions, Dynaudio for example use 6db slopes even though there speakers are nice high end units.

Anyway in summary they will be 6db caps for the tweeters.

Active as Big Kev has covered are powered crossovers where you do not suffer any loss nor have the same sort of phssing and distortion issues faced by passive crossovers.