Hmmm....I've never had a set of speakers just start dying like that. I have, however, had speakers "blow" without my knowledge, and sound crappy (distorted, somewhat muffled, etc.) and after playing with the sound controls, I ended up replacing the speakers. The only thing I'd check before replacing the speakers is that you don't have an effect turned on. Without me actually hearing your speakers make the muffled sound, I'd say that you *might* have enabled the "underwater" effect that makes everything sound muffled. I say *might* only because my son has done this to me, and it took me 20 minutes to figure out that he had sabotaged my audio
I'm not sure if this will work, but try plugging in a headset your sound output. I can't remember the exact size of the speaker jacks, and if they're the same size as the headset jack. If it does work, and your headset sounds fine, then your speakers are messed up. If your headset sounds messed up, then the speakers arent' your problem, it's your sound card (or onboard audio) that's messed up, wich may or may not be fixed by uninstalling and reinstalling the drivers. You could always go get a cheap set of speakers from a dollar store or walmart (you should be able to find a really cheap pair for under $10) and try them on your computer (or borrow a pair from a friend).
Hope all this helps!
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