MBA "Buzzing" Sound When Playing Audio

Hi guys,

So i brought my 2011 13" MBA in to the Apple Store for the buzzing issue when playing audio at 75%-100% volume. This is coming from the right side of the keyboard, particularly the "return" key. If i lay my palm on it, the buzz is gone.

Apple offered to replace both speakers. However, I'd like to know if anyone brought it into Apple for the same issue to have the speakers replaced, and if that fixed the problem.

I suspect it may not be malfunctioning speakers, as the buzz seems to be the soundwave hitting the keys. I don't see how a malfunctioning speaker would produce a buzz that vibrates around the keys. I don't want to bring it to Apple to replace the speakers if it's not the speakers itself that's causing this issue.

How would i explain that to a Genius in a way that's convincing enough that he'll let me replace the entire MBA? To him, it may sound like a minor problem that would not affect the performance of the MBA (at least if i were the Genius this problem wouldn't be persuading enough to give the customer a brand new MBA). But to me, it's really annoying as i like to turn up the volume on my MBA so i can hear more clearly and concisely...