Stan is having issues with his home theater system subwoofer. No bass at all. Leo says that there are two ways to connect your subwoofer. A single RCA jack or an LFE connection (for low frequency).
But it could also be a setting in Netflix. Make sure you have your Netflix app set for surround. Make sure the highest quality is also selected. Also, check the settings in your streaming box.
But if you're using the audio return channel (ARC) on your TV, try using optical out to your AVR. That could give you the full 5.1 surround sound. It should tell you in your AV receiver.