Is the factory radio in the 2005 Acura RSX considered good quality? What should the bass/treble etc be set on?

That depends on if you have a Type-S or a base RSX... The Bose system sounds ok to me for a stock system, but my mom's Oldsmobile is better. I've upgraded everything to components and added a couple 12 inch subs because I wanted more bass and clearer highs, and a better deck with mp3 ability and a built in hard drive. The speakers will sound the same even with a different deck. If it's sounding tinny then you should invest in some decent speakers front and rear and also do an aftermarket deck. It won't hurt to have an ipod adapter too, because you will always be able to play the songs you want without having a bunch of CDs to sift through.