In a large bowl, combine ground beef, bread crumbs, broth, parmesan cheese, eggs, Italian seasoning, garlic powder, onion powder, and salt. Use a spoon, or your hands to work the mixture until everything is evenly combined.Roll meat into 24 balls, about 1.5-2 in in diameter.
Pour the marinara sauce in the bottom of the slow cooker. Nestle the meatballs into the sauce.
Cook on low for 4 hours, or high for 2.5 hours.
