How To Enhance Music Quality of Nokia c5-03?

Hello. Music quality depends on bit rates. I use songs pk for music download where the bit rate is 128 kbps. Now i am using mp3skull because there there the songs can be ordered by bit rate and the highest bit rate there is 256 or 356 that means a supb music quality. But i use only 256 kbps because if you go for higher bit rate then the file size also increases. Hope it would help you. If you found no difference then the only way is to upgrade the phone software if it is avilable.