So After reading that , I should be able to use this https://www.crutchfield.com/S-u78bm1dW97B/p_136CLRLC/JL-Audio-CL-RLC.html for the balanced inputs? Just chop the pre-amp and replace with RCA then wire that in and send that back to the amp. Leaving the control knob from the amp to take care...
So over the past few days I've been reading threads from here and 9thgencivic about adding in an aftermarket sub for my 13 Si with premium audio and nav.
I think I have everything down but I'm still having trouble understanding how to do it. I would like to keep the factory amp running...