Thank you for taking the time to post and welcome to the Bose Community.
I'll be happy to assist you with any issues but can you confirm - are you experiencing a weakened bass on your system?
Have you recently moved your system to a new location - with a new placement of your components? This may have an effect on the output of the system. What are you using the AM5 system with? On the device being used, have you checked the treble and bass control to see if you're able to increase the level of bass response?