The DD-15 has been in my systems for a couple years now. I have no thoughts of upgrading to a DD-18 or any other brand. The volume is set at 7 or 8 at the most. It just continues to amaze me with sound that comes out of it. The new Auto EQ makes it even better. Last week I picked up The Who "Who's Next". The bass on that record is fantastic,never heard it like that before.
Tim
Tim