Normal
If the amp has low level input, and he gets a processor, then why not leave the Low Pass Filter at it's highest setting (assuming it can not be bypassed), leave all the amp settings at 0 (which you would do with a stand alone amp anyways) and treat it like any other sub with the processor. I'm not a huge fan of prefab sub/box/amp combos, but it's no different to a processor than any other sub, box, and stand alone amp. The processor has no idea where the amp is mounted.