To the bowl of your slow cooker, add the meatballs, sauce, broth, water, garlic, basil, and Parmesan cheese.
Cover and cook the soup on low for 6-8 hours.
15-20 minutes before you're ready to serve, turn the temperature up to high & stir in the uncooked pasta. Cover, and continue cooking 15-20 minutes, or until the pasta is tender.
Salt & pepper the soup, to taste. Serve topped with freshly shredded Parmesan, if desired.