Hi Spiner
Those are near field measurements of XLS 10 after I apply those setings
My goal is to boost, apply linkwitz transform, at lower end, I manage to do that.
You did read Davids posta about
"The a1 and a2 coefficients need to be negated"
So the result that you get for those coefficients you need to "reverse" them. If thay are positive you should make them negative (-0.xxxxxxxxxxxxxxxxxx)....
If thay are negative you should make them positive

You could write which model of driver/speaker you are useing and maybe I could run that via software ?