What makes a really great pair of headphones? The basic answer used to be sound quality, but modern headphones offer so much more than just audio chops. Armed with a blindfold and six of the most popular pairs of over-ear headphones available, WIRED commandeered a recording studio in East London to find out. Each expert was interviewed separately, and had no prior knowledge of the headphones or brands on test. Each pair of headphones was given a letter—A, B, C, D, E, F—and the testers were free to switch between pairs to compare and contrast.