I have a 98 gtp with the Delco premium 8-speaker system. I was putting in new rear speakers yesterday and found what LOOKED LIKE capacitors on the positive wires of each of the four speakers. I've read that the 6x9s are only supposed to receive bass and the 4" receive treble. I'm curious if this is how the factory system creates a crossover or if the guy I bought the car from had a system and I need to remove them since I don't have a sub?

that capacitor looking thing is a crossover device, keeping only bass frequencies to the 6X9s and the higher frequencies to the tweeters.

and that comes with the factory system?