03 Buick Century New Car Bad sound!

Have new 03 Buick Century with stock am/fm cassette with trunk installed Pioneer 6 disk changer - Sound was not close to what I need, so I just purchased some infinity Kappa speakers. Kappa 52.5i Infinity Speakers 2-way 5-1/4" and Kappa 692.5i Infinity 2-way 6x9 Speakers. Any suggestions on how I should configure this setup. I was thinking of just installing them straight outright or having a 2 channel 340w power amp for the back 6x9's and just running the 5x1/4 off the stock radio. Any Suggestions would be appreciated.

Sincerely in need of better sound - Brian

Brian, ever been to a concert before? Would you pay $100 for your ticket to have the guy sing from behind you all night? Your front speakers are your most important in there. Ignore wattage claims on the amplifiers, Do not believe what you read. The speakers are a good choice (I am not a Infinity dealer currently), take it a step at a time. Replace the stock speakers, if you like how it sounds, leave it alone. If you want it to play louder, then add a smal 4channel amplifier, no more than 50 watts rms x 4 (the size of the fuse of fuses in an amp like this is about 50 amps combined). Buy an american built amp like the eclipse ea2422. An amlifier will do a lot of this for you, it will obviousely make it louder, it will give the speakers way more definition at lower volume levels (improved bass response) and generally make your car sound like you want it to. You will need to buy yourself 2 hi - lo adaptors (scosche loc-e) to convert the stock speaker wires from all 4 speakers to a signal that the eclipse amp can use.

Like I said though, start simple, put the speakers in, even better is to put some sound deadening material in the doors while you are there (do this, it can make a crappy speaker sound really awesome) then add the amp if necessary. Let me or the guys reading know of how you make out.

Thanks, good advice! Why pay more if just installing the new speakers will be enough. I'm expecting a 100% Better sound with these Kappa's - Had 4 in my old car (was the most valuable part of the car) and they sounded great. Thanks again, Oh one more question if you don't mind. These new speakers come with an crossover do I need a special adapter to connect them to the existing speaker wire ?