Hi 660griz,
Sounds like you're talking about a problem with the subwoofer in your sound system. If you can locate it and get to it to inspect, perhaps the problem will be self-evident. If you can't get to it, you may have to ask your dealer to fix the mounting or replace the speaker, or otherwise figure out how to get it working satisfactorily.
Btw, Technical Service Bulletins would be issued if there were a widespread problem and a specific course of action needed to be communicated to dealer techs. This sounds more like a routine manufacturing defect of some kind that would be handled under the normal warranty terms.