I have several very loud pairs of headphones and I wanted to be able to listen to them softly sometimes. The android default for number of volume steps is 15, and even at the lowest, it was too loud. So I figured out how to do this. Works great on the Thrive, so I decided to make a tutorial as I did it to my phone (Thunderbolt). ROOT is required.
It is linked below.
Increase Number of Volume Steps In Android
This forum doesn't allow HTML, so I converted it to BBcode in the next post, but it's nicer to read in the link. Hope this helps someone else out!