What type of files are you trying to improve the dynamics of? If you are dealing with "lossy" files such as MP3 what you may want to do is some form of "compressed music enhancer" to help replace the music info that was thrown out during encoding, not just increase the dynamics (although I will admit that most new pop recordings have next to no dynamic range).... BTW you do not need to worry about a CD's 96 db dynamic range because in real life a listening environment has around 70 db between the noise "floor" of your room and max volume level that most audio systems can produce.
Can we increase dynamics?
It might be a silly question, but since recordings have compressed dynamics (to work on average systems) is there anything to expand dynamics back to normal (or at least close) - either in form of hardware "expander box" or software I could batch convert my files with?