I'm by no means an expert, but I do use audacity and the same card as you do, I find the biggest help in my recordings in to adjust the input level way down low then gradually thru trail and error bring it up until I'm satisfied, another thing is mic placement, try different locations until you find that sweet spot. Just my thoughts, some of the more experienced will surely fill you in and correct me if I'm wrong.
Thanks tsidewinder for the link might just check out the differences myself
