I have some Galaxy Bud +'s and one side was sounding much lower than the other. I tried resetting and no luck but after digging through search results I saw someone mention that ear wax had got past the metal mesh piece and to use hydrogen peroxide and rubbing alcohol to clean it. I tried it and sure enough it fixed my issue. This would obviously apply to all brands of ear buds and I'm sure this may be common sense for most but I never thought about it and it solved my issue