Found this on crutchfield, hopefully it helps. Seems like all you would need to know.
"To install: Slip the female connector of the bass blocker onto the positive speaker terminal, and plug the male connector into the speaker lead. If you don't want to use the terminals, cut them off, cut the speaker lead at a convenient location close to the speaker, then insert the unit on the positive speaker lead and insulate the connections. Bass blockers are not directional, so the orientation of the Bass Blockers on the positive speaker leads is not important."
