I was just looking on their site for some info and noticed a difference in the sensitivity ratings for their new HT210S and EX112S sub. The HT has a rating of 100db, whereas the EX sub is only 96 db. Now I've heard that a perceived difference of +3db in a cab requires a doubling of wattage. So, before I contact Jim himself for an explanation, why the discrepancy of 4 db? Is the EX112S there to provide low end presence and less than equal volume to the HT210S?