I'm sorry to hear you're noticing an issue with the quality of audio from your SoundTouch 30 system. When did you notice the reduced bass, and have you tried playing music from various sources to compare how they sound?
Also, are you saying you have another SoundTouch speaker that's working perfectly fine?
Feel more. Do more. Be more. Come check out my profile here. 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!