hands down, i recommend replacing the front speakers first - they are the most important speakers in the car - you hear them the most. the rear 6x9 are basically factory midbass - you can remove them for more bass from the sub.

any speaker sounds better with a proper amp on it. same is true for aftermarket speakers, 6x9 or 6.5's.

if you want it to sound better than stock, get an amp to run them, and install them well - maintain the same seals as factory. this will require creative fabrication on your part - but is worth it.

 

so i have installed my subs a while ago, AWESOME. I thouhgt the were pretty loud, until i got back to school and heard cars with much better systems. So i just got some money and bout a pair of 6x9s sony 3-way, for the back deck, i know i should have done the front ones but they looked and sounded more complicated, the 6x9s sould be here wednesday, and then once i get thoes in im going to buy componet speakers for the front, i really need help understanding crossovers, location of the tweeters, and if i need an amp or if i could use the stock wiring, that is why i just went with the eaiser rear deck.