For all their convenience, earphones have never matched the quality of over-the-ear headphones (a.k.a. cans). Their compact drivers can't range from deep bass to high soprano. Companies have tried using multiple, differently tuned drivers, but that can degrade the signal. Instead, designers at Sennheiser built a new, seven-millimeter driver and acoustic housing for the IE 800—the first earphones with over-the-ear sound.