Ok 2 R. fosgate T1000.1bd ,2 RF T212D2 subs. the gain is set at around 33% the freq. at around 80. Ok heres the problem the phase(0 or 180) the subsonic filter on or off, not to mention the HU has all kinds of settings . bass setting, loud setting, the low pass high pass filter. plus a EQ that has all kinds of settings as well. last but not least the bass knobs that come with their own gain and Freq. THANKS