I have a powered subwoofer that has no rca inputs, only speaker-level inputs. The subwoofer output on my head unit is rca. How can I wire it to the sub so that I maintain all of the frequency controls that are available only with the rca hookup? Thanks , this is my first car, and I am trying to install a decent sound system using hand-me-down parts, as I have no money left in my meager budget for a new system.
