Questions on adding a sub to OEM system, 2014 GT- Adding a sub to OEM system (non nav) Options

[ttttrigg3r]

I own a 2014 Elantra GT 5 door.
I want to :
1. Add a subwoofer (10" or 12")
2. Replace the rear speakers (maybe)

The OEM receiver has no RCA (also called low voltage) output. It only has high voltage or speaker level output. To add a subwoofer, you need a Line Output Converter (LOC) or an amp that has High Voltage or Speaker Level inputs. I've read that amps with speaker level inputs is the better of the two.
I've never done anything involving speaker level inputs before. Has anyone done this before and what do you think of the sound quality. I turn my music up louder than the average user and would hate to have distortion or noise after installation.

I am currently looking at this amplifier.
http://www.crutchfield.com/p_130GMA3602/Pi...602.html?tp=115
Aside from the amp and sub, what else would I need to hook this up? For RCA it's just RCA cables, but here I see some type of 4-pin plug.

What size are the speakers in my car? (2014 GT 5 door non-nav)
Is the wiring diagram for the stock stereo the same as the sedan/coup and previous years (2011-2013?)

This post has been edited by ttttrigg3r: Sep 5 2014, 06:47 PM

[roydjt]

Swapping the rears is straightforward. Due to the placement you won't hear much high treble from them but you'll definitely notice the midbass and mids. The fronts are your choice. If you use the stock tweeters as well as the full-range speakers, you'll probably find the sound to be a bit bright on the high end, but you might also like the results so you have to experiment.

-Roy