Do you care to give more information so it can be clear exactly you want to do and why so you can possibly get directed the correct way... Are you trying to do it for music, ringer, alerts of video audio files...
Have you tried the Equalizer app on the market, it does edit the files but it allows sound fine tuning and better volume.
https://market.android.com/details?id=com.smartandroidapps.equalizer&feature=search_result
Do you have to be rooted to use this? I see no download option in the market. I tried searching and couldn't find the app at without your link.