Ive used them before but always had them with the system when it went in so i have no clue if they actually help or not. I do not have one now but am thinking of getting one so id like to know if they work or not? If so does the kicker 3 way crossover work well? Like ive said i had one before but it was with the system. I liked having it, as it gave me a little more fine tuning but is it worth the $100 for a new one?