Sony touts its XBA Series as the first to use its "microsized balanced armature drivers." The $80 XBA-1 and $100 XBA-1iP in-ear headphones are the least expensive models to feature these drivers, and they sound exceptionally pure and precise. The XBA-1iP is very much an audiophile-oriented design with a clearer sound than conventional headphone drivers, and I recommend it to music lovers who shy away from bass-blasting genres.
Design and features
The XBA-1iP uses one full-range balanced armature driver in each earpiece fitted to a liquid crystal polymer inner housing with an ABS outer housing that suppresses vibrations. The small gunmetal-gray-and-chrome earpieces are very light, which is one of the reasons the XBA-1iPs are so comfortable to wear for long periods of time. In fact, they're more comfortable than the larger and more expensive XBA models.
The cable is 48 inches long with an inline microphone and three buttons that control volume and track navigation on Apple devices -- if you don't have one, the plain XBA-1 headphones lack those features and sell for $20 less. The flexible cables are prone to tangles, however, and you'll likely spend several minutes with a jumbled cord if you simply jam them in your pocket in transit. Another hiccup in the design is the lack of reinforcement where the cable attaches to the earpieces, so I expect the XBA-1iPs to have lower than average reliability in the long term.