A co-worker of mine had Bose noise cancelling headphones that broke where the ear cups mount to the frame. On inspection, the whole design was shoddy, weak at the point of most stress. So in my opinion, not only does Bose get an "F" in the electrical and acoustical engineeing departments, but they also get an "F" in structural and mechanical engineering. They get a "B" in aesthetics and an "A+" in marketing.