First off welcome to the site! I've not personally heard the Adire sub you have, but I know one of the keys to subwoofers is location. Location, location, location. Location makes/breaks a sub (and speaker) sound entirely.
Another thing you may want to look at is a parametric equalizer to help flatten your frequency response curve. Behringer makes a few good ones. Also if you are looking at an autocalibration type EQ, then SVS's AS-EQ1 is a good alternative that seems to be getting rave reviews!
Another thing you may want to look at is a parametric equalizer to help flatten your frequency response curve. Behringer makes a few good ones. Also if you are looking at an autocalibration type EQ, then SVS's AS-EQ1 is a good alternative that seems to be getting rave reviews!