Currently have a Sundown X-15 v1 dual 2 ohm in a 4 cu ft box tuned to 32hz powered by an Audiopipe Apmi 2k wired at 1ohm. My question is where should I set the Subsonic filter, and the Low pass filter at? Also, I have an oscilloscope to tune the amp, but Im not sure exactly how to tune it since I have a Rockford Fosgate Balanced Line Driver that has a gain knob on it too. Any help would be appreciated.