I watched a movie downloaded from iTunes on an airplane yesterday with my 2011 13" MBA. I have a pair of Klipsch earbuds that work well for most applications, but I couldn't get the headphone volume loud enough to hear over the airplane background noise. I've used a 2010 MBP in the past with the same earbuds, and never noticed this problem. Anyone else notice this? Is there a better set of earbuds to solve this problem? I don't went to lug around big headphones when I travel. Thanks for your help.