Owned a pair meself, D9's definately kick some ass. At one time I had the D9's sitting in front of the k-Horns, and a pair of Heresies on top of each cornerhorn. A 400 on each Heresy, tr-amped the k-Horns with a Spec2 on the bass bins, a 400 on the mids and a small Kenwood integrated on the tweets, and a 700 on the D9's.........it got loud......