I also finally sound deadened the inside of the console to eliminate the vibrations a little more. I have to say this made a tremendous difference in the clarity of the sub as well as the overall loudness. I had my doubts...
Inside of the console shell, after:
Sound deadener used is Second Skin's Damplifier Pro. I am super impressed with this product and I am a new believer in sound deadening!
The sub is a Dayton Audio Reference ** 10" subwoofer from parts-express in an MTX Thunderform enclosure. I also added some Damplifier Pro to the inside of the box because it seemed a little thin to me (I'm used to huge MDF boxes for subs...