I have a Rockford P1000-BD amp. Just wondering if I can add a bass knob to the amp? I have a kicker amp in my other car which has the bass knob. My gf hates bass so it will come in handy when I want to turn the bass down. Otherwise I'm looking into getting a Skar 1500 amp. But since I already have this one, it will be a much better option for me if I can just add it. Thx!