Clean your dog's ears. It's normal for a clean ear to have some wax in it, but there shouldn't be any particular smell to it. To clean your dog's ears, apply some ear cleaning solution (bought at a pet supply store) to a cotton round. Not too much or it will drip into the ear while wiping. Wipe dirt and wax away from the inner ear, but don't rub vigorously, as this might cause sores. Don't push too far into the ear, either. If your dog has drop ears like a bassett hound, wipe the inside of the ear flag as dirt collects there as well. The groomers rule of thumb is to clean only what you can see.
^ Bridgett M. von Holdt, Emily Shuldiner, Ilana Janowitz Koch, Rebecca Y. Kartzinel, Andrew Hogan, Lauren Brubaker, Shelby Wanser4, Daniel Stahler, Clive D.L. Wynne, Elaine A. Ostrander, Janet S. Sinsheimer and Monique A.R. Udell (19 July 2017). "Structural variants in genes associated with human Williams-Beuren syndrome underlie stereotypical hypersociability in domestic dogs". Science Advances. 3 (7): e1700398. Bibcode:2017SciA....3E0398V. doi:10.1126/sciadv.1700398. PMC 5517105. PMID 28776031.