If I just upgrade my headunit from the base 05 HU I have, will that alone improve my audio quality. Also, does the bose system have more speakers than a base, or just an added sub and 6 CD changer?

 

from what I read it should make a very noticable difference, especially if the HU has decent power

 

Bose OEM sound bad.

 

You'll either have to wire the line level outputs into the Bose amplifier harness or by-pass the two Bose amplifiers in the car. I did the second method by-passing the amplifiers while awaiting the arrival of my subwoofer box and amps. It wasn't that bad at all but the Bose speakers were pretty poor sounding compared to the upgrades.

A couple of pictures:






Note that the factory crossover is a single tiny cap on the back of the component tweeter. The Infinity's are those huge clear plastic boxes. The crossover is nearly as important as the darn drivers.

 

i remember those pics!