Okay, well just so you know for future reference: 1. Unless you have an oscillioscope, don't use bass-boost. Never. Not on the Amp, Not on the Head Unit 2. Set your gain using a DMM if you aren't able to do it by hear (i'm not able to do it by hear, follow this guide Setting Amp Gain) And on the subwoofer side of things, i can reccomend a BTL. But that's not saying much; it's the only heavy duty sub i've had. Hopefully you can get someone who's had experience with multiple high-end woofers to comment. As i try to only talk about the things i know best I also only hear good things about the xcon!