Welcome to the Bose Community today! I would love to help you with any product questions you may have.
To start with I would like to make you aware that we don't have a SoundTouch 500, only the Soundbar 500. If you are referring to the Soundbar 500, then yes you can use the Bass Module 300 with this.
The Bass Module 300 can be used with the following:
Bose TV Speaker
Smart Soundbar 300
SoundTouch 300 Soundbar
If you have any further questions, please do let us know.
Feel more. Do more. Be more. New to the community? Check out the Getting Started board. Help others find answers to your questions by clicking on 'Accept as Solution' at the bottom of a reply. If you see a post you like, make sure to give it a thumbs up!