I'm just wondering how it's the case that every brand of headphone can be addressed as if every single one is identical in sound, quality, etc. Reviews can be made on the subtle differences between brands based on a single data unit, while difference in experiences are always attributed to taste and such. Even the production of semiconductor devices have fairly large margins for error and require a selection process for bad batches. Are headphone drivers so indelicate that they can easily be reproduced without difference? If that's they case there shouldn't be so much of a price difference between brands and models. Are the materials and product processes so well refined that it is entirely consistent? Being a student in engineering, I find it hard to believe. So I await for enlightenment on the subject.