[phoenix]

I have ha dstandard componet's up front on previous car's but have seen many with passive-crossover's as well, this may sound daft but what are they for and how are u spose to wire them up?

 

[novamad]

You would normally find a passive running something like a mid and a tweeter.
The passive splits the frequency from one output so that you now get two outputs, one output has all the low frequency and you hook that up to your mid the other output has all the high frequency and you hook that up to your tweeter.