ok man, lets see what we got here. First you have a prefab box, a sub that is getting only half its rated power, and a loose nut behind the volume control. Now don't get mad, i'm just messing around with you. First and foremost with a prefab box and half rms power, you are not going to pound. When you turn the gain up, yes your getting more output from that amp. But your going to be sending dirty power to it. And while it may pound loud for you, your gonna blow that fucker like ia chinese hooker on 2 dolla sucki sucki night. Your best bet is to build a box that is a lil bigger then spec, get some decent size port area going. When you do that your going to make that sub louder on the little bit of power you have. DO NOT turn the amp up just because it sounds better to you. Ohms law and power output is just that LAW. It's not a suggestion, there is no way around it. Getting loud in the car audio world is about test, test, and when your sick and tired of testing..............test some more. And one last thing we're all lose nuts in one way or the other.