Forgive my stupidity here but I'm very green to car audio etc. I had a Volvo 940 and had a new JVC CD player put in it and it sounded great. I sold the car and got a Mitsubishi but when I fitted the CD player in it sounded awful. I guessed the speakers were the problem and bought some new 4" x 4" for the front and 6.5"'s for the rear. Not massively expensive speakers but they sounded good in the showroom. It still sounds bad and the bass just distorts at medium volume. I have just noticed that the fronts are rated at 4ohm and the rears at 8 ohm. Can someone explain the relevance of this and could this be the problem. I don't want a huge kickass system but just to listen to my cd distortion free.
part of the problem is that with many factory systems, the speakers are perfectly matched to the head unit, power, etc., and by doing this and tricks commonly used like odd speaker impedances in factory systems, it makes it nearly impossible to replace one part of the system effectively.
the 8 ohm speakers have twice the impedance, so they will get half the power the front 4 ohm speakers are getting. that's the relevance there. ideally most 'door speakers' for a car are all 4 ohms. subs are usually 4 or 2 ohms since they need more power from an amp to work well.
here's what ya want to do.. use a head unit that has decent power and built in crossover and EQ stuff, like anything mid level from Alpine, like the 9831 or 9833. then use that to drive your front and rear component speakers, all at 4 ohms. replace the 8 ohm ones, and use good speakers in the front for sure. this makes a big difference. after that, look at adding a small, self-powered woofer to the system, such as infinity's basslink model which is all over ebay new for pretty cheap. that'll fill in the missing low end and help a lot. it supplies a 10" woofer and equally sized radiator. they work very well if you're not after deafening bass.
what kind of mitsubishi? some have a "premium" sound system with an amp, like the eclipse. you could be double amping it. definatly replace the front and rears like glass said.