Need help, losing my mind.

Ok Sorry to bother everyone. I am in a bind here and have no idea what I am actually doing. So I decided to install a sound system in my Pearl White 2014 Forte GDI Koup. I do not want to replace my head unit yet. I am doing this build piece by piece. I have the windows blacked out, And a few other various things. But it is just the start of a work in progress. I wanted it to be loaded, which it is, but they didn't have the color I wanted which was black. But I am getting off topic. Anyways, I want to install my Sub and Amp combo I have. Which is a pioneer type R 12inch sub in a custom airflow box with an audio pipe 1000w RMS amp. This thing hammers. Everyone who has heard it is baffled that I have one sub hitting. I tell them it is the fact its wired to 1 ohm.

Ok so here is my problem, I have it all ran and set up except for my low pass converter or whatever it is. It switches my two amp jacks into a speaker setting. I have done a lot of stereo build before but have never needed a low pass converter.

So my question is:1 does anyone know what the color codes are to the wiring. Please keep it simple, the wiring is confusing as hell because I am used to the standard and none of these have it. If anyone can first tell me which set of speakers do I want to tap into.
: 2 With the low pass converter it has four wires, positive and negative. and a brown wire coming off. The instructions are confusing, do I use two wires only for one sub? all four? and whats with the brown wire. Im not tech advanced but enough to install this.
: 3 The instructions to the converter are very very confusing because it lists seperate ways to wire it up based on your build. Any help and or tips would be appreciated.

P.S I have two fortes, Ones a Koup the other a sedan. I intend on replicating this with the sedan also. Photos of both my fortes below.