The sub is everything I hoped for and it is plenty loud in my 14' x 11' enclosed basement HT room. It shakes eveything in the adjacent rooms even though the volume is about 10 db below reference. While watching Finding Nemo, I was really afraid that my next door neighbor would come knocking down my door (I live in a corner townhouse). I can't believe that some of you have 2 (or more) of deeper and louder (PC+) SVS subs in your room. Anyway, would I "feel" a lot of difference, at the volume I listen to and in the room size my gears are in, if exchange my 20-39 PCi and get a 16-46 PCi or PC+?