Hey guys, I bought my machine November 2011, so I don't think it is likely to be an early production version. I have rattly, buzzy, irritating and generally crappy sound, intermittent, mostly from the left hand speaker. I saw the Stickied topic here, and have since totally disassembled my machine. I found no physical problems at all, cleaned out a bit of dust, and use a little blu-tac to more securely cushion the left speaker to the base of the machine. The buzz happens with low and high frequency sounds in all genres of game, film, and music. When not buzzing, the sound quality is very nice and full (Using TruStudio External setting).
Seeing as I found no obvious physical problems, and this does not sound like a driver issue (A dozen or so drivers tried, so it really is unlikely) does anybody have any idea at all where to start looking, or what the problem is? An official comment from ASUS would be nice...