I just thought I would add a little information pertaining to my situation to this conversation.
I purchased a new 2013 Haswell MacBook Air approximately 5 days ago from the US Apple Online Store. I am a Canadian citizen but had a US gift card given to me, so I arranged to have my Air shipped to an address in the United States.
I discovered the speaker problem with my MacBook Air a few days ago while watching Netflix and Youtube on Safari. Since that time I have contacted Apple support who seems to believe that this is a hardware issue and has advised me the best option is to have my MacBook Air replaced with a new unit.
There is however one big problem. Apple support insists that ship all items relating to the return (return shipping label, and replacement MacBook Air) to the US address I picked it up at. That address is a 6 HOUR DRIVE away from me. There is now way that I can drive there to ship the computer back, and then drive there again to pick up the replacement unit.
I wish they could just handle this replacing my MacBook Air using the Canadian address where I live. I am really frustrated to say the least and I'm not sure what my options are at this point. This is the 3rd MacBook I have purchased in the last three years and I had really hoped that Apple would be more accomodating.