So is the External for the Kappa? You want to remove the stock XO and add your own? Take care of the dip below 1 ohm? Amp killers..
First Watt B4 1500 new, 1000-1500.00 used
https://www.firstwatt.com/b4.html
Regard
First Watt B4 1500 new, 1000-1500.00 used
https://www.firstwatt.com/b4.html
Regard