Do you have the amp bridged to the sub? If so it should be 4 ohm bridged, not 2 ohm. Rated 560 watts RMS. Make sure you have your crossover set to Low pass, start with around 100hz and crank it down to your liking, I usually went with around 80 when I had a daily driving system. Make sure your subsonic filter is set low, start with the 15hz setting and adjust up if need be. Play with your "Bass EQ" if you'd like, I have no idea at what hz it's set to peak at. Lastly make sure your gain is adjusted adequately as well.
If none of that works for you, and you aren't suffering from extreme light dimming due to power loss (shouldn't be an issue with that amp) turn to your head unit, make sure your sub output is set correctly.
Make sure your box is at least 1 cubic foot as that's what the minimum recommended box size is, with the maximum all the way up to 4.6 ft3. Assuming that box is sealed.