Ok. Here we go. This amp was probably designed with subwoofers in mind, so there are some things you don't really have to worry about. The subsonic filter is one of those. Just leave it off. Next, the gain control. If your gain goes from 200mv to 9v, 200mv is the lowest setting, with 9v being the highest. To set it, turn it all the way to 200mv and turn the volume on your head unit about 3/4 of the way up. Then, turn the gain knob until the music is either loud enough for your ears, or until it distorts. If it distorts, turn the gain knob back slightly until the distortion goes away. You don't necessarily have to have you amp on high pass mode. I think I'm running my on full, because it just happens to sound better. Plus, I cross my frequencies over with my head unit anyway. But, aside from that, just make sure your amp isn't on low pass (lp). The boost frequency and bass drive are functions I am not familiar with. They are probably there for subwoofer use, and personally I would keep them off. But, if you are curious, play with them and see how they sound to you. Other than that, if there is anything I did not address, mess with it and see how it changes the sound. It is the best way to learn. Use your ears, they will tell you a lot more than the internet. Good luck.
