When setting a channel or sample volume level, the number put in doesn't seem to directly relate to a percentage of maximum volume. For example, setting a channel to play at "50" seems much louder than 50% volume; setting a sample to play at "5" also sounds louder than 5% of maximum volume. It seems the volume grows exponentially quieter as the number ranges downward between 100 and 0.

Is there a formula to this? I'd like to have set volume levels of 100%, 50% and 20% of maximum volume.