ergo25

Hi, First of all, let me say that I've been quite happy with my Klipsch 2.1s. They were my first foray into good audio and I still consider them a quite respectable little system. No real problems beyond a mildly noisy potentiometer for the first 5 years. However, after 6+ years of music and movies, the sub woofer has started to develop a distinct rattle on low effects in movies. From the testing that I have done, the rattle seems to be nearly inaudible above 100 Hz but as soon as the signal dips down bellow about 70 Hz it becomes quite noticeable. Around 50 Hz the rattle is louder than the direct sound. Though audible at all volume levels, the amount of rattle seems to increase exponentially with higher volumes. I have confirmed that the rattling is coming from the subwoofer and not anything in the room. I've tried some exterior dampening (blue tack, weight on top of speaker, changing the coupling with the floor etc.) but that hasn't really made any noticeable difference. Also as far as I can tell there are no airleaks or other forms of external damage to the enclosure. It is hard to localize the rattle inside the sub woofer but it seems like the rattle is coming from the side firing speaker. Does anyone have any advice on what may be causing this and how to stop it? What trouble shooting steps should I take? I'm fairly proficient at speaker work (just finished a set of Fostex FE127 monitors for example) so I'd be willing to crack it open and do a bit of repair work myself but I'd like a better sense of what may be causing this before I take it to that step. (Also is there a walkthrough for the disassembly process out there?) Honestly, after 6 years of loyal and sometimes hard service, something may have simply worn out but I have a bit of sentimental attachment to this set (they've been with me since college after all) and would love to try to keep them up and running. Thanks in advance.