Wanted to share my stereo upgrade story... especially since nearly everything I needed to know I got here on this forum!

I wanted to upgrade the speakers, but keep the head unit. Of course, I had to bypass the Bose EQ, which resulted in low volume. I installed a Audio Control Three.1 line driver/crossover/eq in the 1/2 DIN space where the factory cd changer would go (just above the HU). I can't say enough about what a great unit that is--it boosted the preamp signal so the system is loud, plus gave me some eq control, plus provided sub out.

As for the subwoofer, it was extremely boomy (not in a good way) before hooking it up to the sub out on the preamp unit. I attempted to bypass the Bose EQ, but the amp behind the rear seatback does not accept a normal preamp signal. (Could barely hear it). So, I took the sub out from the three.1 and sent it in to the Bose EQ--the result was excellent. (Not as nice a good sub with a strong amp, but excellent for stock). This gives me exact frequency crossover (I'm using 90hz), as well as sub output control from the 3.1.

So, if there's anybody out there wondering if they can make the system sound good without changing the dash; the answer is yes. (Of course, it would have been cheaper and easier to just replace with a nice head-unit).

The sound-quality is good enough that I now know how terrible the FM modulator with my CD changer sounds. (Last remaining project--install a Blitzsafe adapter to get the CD changer input into the system correctly).

I'd be glad to share any technical details that anybody might want.