Audio Systems: Regarding audio matching, exact model number, sony mp3 player

Question
I have a Sony MP3 player with Sony oval speakers powered by a Sony 4 channel amplifier backed up by a Blaupunkt 10" woofer i feel that the sound clarity and the bass is not enough . so i just want to know what can be done to improve the above by changing the head unit or by doing any other modifications  

Answer
well changing the head unit isn't going to improve sound quality. pretty much all cd players sound the same.  they just have different features depending on what you spend.  but the features rarely have anything to do with the sound quality.
things you can do to improve sound quality would be to get better speakers UP FRONT.  leave the ovals in the rears but turn them down compared to the front speakers using the gain controls on the Sony amp.  the Sony amp should be set up so that each door speaker is going to each one of the 4 channels on the amp.  MAKE SURE you get all the positives and negatives right on all the door speakers when connecting them to the Sony amp.
then you should have a separate amp runing the 10" woofer.
using a 4 channel amp to drive the sub and door speakers is definitely going to sound like crap most of the time.

so depending on what model this blau 10 is I'll pick out an amp for it so let me know what the exact model number is.

that should make a huge difference.  if you still are craving more sound after that we can switch the 10 to a 12 or a set of 12s depending on money/size/etc. there are ways we can get an amp now that will work with your current 10" sub and be a good match for future setups as well.  so let me know a budget we have to work with here.  
that way we can determine what's more important to buy to get you the best bang for the buck.