Adding Powered Subwoofer to stock JBL (2010)

Hey guys....I am looking at adding just a little more bass to my stock JBL 2010 system (with 8" sub). I don't want to replace the HU just yet. What I need to know is where on the HU can I can run the speaker level inputs from the amp? Do I tie them in to the existing speaker level outputs? I am looking to install this powered subwoofer...

http://www.crutchfield.com/p_777B8PT/Sound-Ordnance-B-8PT.html

All of the installation makes sense, except how I get signal from the stock HU to the new powered sub. Also, I want to keep the stock amp and sub.

Any help is appreciated!

 

Yeah most people do start from scratch, but I'm not looking to invest that much into at this point in time. Where is the JBL amp located?

 

so from what I can tell, my guess is the stock amp is located behind the plastic panel that is behind the rear seats. Can anyone confirm or deny this? Also, I have tried removing this plastic panel before but failed miserably. Are there any write-ups on getting this panel out?

 

I took my plastics out so long ago that i don't remember exactly how, but the bolts for the plastics are 10mm. Take all those out and then dont be a wimp when you try to pull the plastics off. They are held in with several white plastic connectors that are not easy to pull out. Just pull hard and be as careful as possible, but they will come off eventually with some persuasion. The stock amp is bolted to the stock plastic enclosure for the stock sub.
I'm not sure what the speaker wires are, but tap into the four wires for the stock sub if you are just lookin for a sub signal(you cant miss the connector going into the sub box it only has four wires for the Dual voice coil stock sub), thats what I did for my custom sub addition. I will do a writeup on how to add a full sub system to a JBL stock system someday once homework slows down and I get off my lazy ass hope this helps out

 

Sweet...installing this new sub should be a breeze then

One last question...how do you suggest tapping into those wires? Previously I have just cut the wire to be tapped and used a wire crimp connector to connect all three ends (the two ends from the wire being tapped and the one end from the new wire). Is this ok, or is there a more reliable way of tapping wires?

 

There are these things called quick connects or something that allow you to tap into a wire very easily. They are at walmart or ACE or everywhere. Just use four of those and you are golden