ok, im getting a rockford fosgate 500BD amp, i have a kicker solobaric L7 12 inch. i am also getting a ported box, it says in the manual that i need a subsonic filter for the protection of the life of the sub, do most amps come with subsonic filters??? someone please help
a subsonic filter is built into most amps. the amp's specs will tell you if it has one or not.
a SSF blocks frequencies below about 20Hz. these are outside the human hearing range anyway, so the SSF serves two purposes: 1: a SSF prevents the amp from wasting a tremendous amount of power trying to reproduce frequencies you can't hear anyway. 2: it protects your subs if they are in a ported enclosure, because below the frequency of the tuned port of an enclosure, the sub is very hard to control, and can easily lose all damping. This means the sub can easily over-extend and get damaged. the SSF prevents this from happening.