Car Stereos: Upgrade speakers in 2008 Trailblazer using factory stereo, 2008 chevy trailblazer, chevy trailblazer

Question
Brian,
I own a 2008 Chevy Trailblazer (base model, no Bose, single cd) and would like to upgrade the speakers without upgrading the stereo.  Is this possible?  Would the sound quality improve?  Is it as simple as removing the old speakers and installing the new speakers (I am not too savvy when it comes to electrical components but know how to wire up speakers (blk to blk, red to red, ground to ground)).
Thanks for your assistance,
Chris

Answer
Hi Chris,

Replacing the speakers in your SUV is likely to be even simpler than you think.  Each speaker has only a positive and negative connection (no ground).  However, the wire colors aren't red and black.  Here's the GM speaker wire color code:

Left front (+)  tan
Left front (-)  gray
Right front (+) light green
Right front (-) dark green
Left rear (+) dark brown
Left rear (-) yellow
Right rear (+) dark blue
Right rear (-) light blue

You can make the job easier by using Metra 72-4568 speaker harnesses.  These connect to the factory speaker plugs, so you don't have to cut any wires and there's no possibility of mixing up the positive and negative connections.

I think you're likely to get a pretty significant improvement in sound quality from upgrading your stock speakers, even if you keep the factory head unit in the system.  

Hope this helps!

Brian