Sony claims that its new $349.99 XBA-4's sound is "optimized for audiophiles," and my anecdotal testing confirms that this is truly a great-sounding set of headphones. It features Sony's newly designed "microsized balanced armature drivers," and in fact the XBA-4 uses four of these drivers in each earpiece. Other less expensive XBA models, namely the XBA-1, XBA-2, and XBA-3 have one, two, and three balanced armature drivers in each earpiece, respectively. The XBA series is the first generation of Sony headphones to feature these drivers, which produce clearer sound than conventional headphone drivers. With excellent noise-blocking performance, a comfortable fit, and a sleek design, the XBA-4s are sure to satiate any audiophile's hunt for a balanced in-ear headphone.
Design and features
The XBA-4 is the flagship model in the XBA line and uses four balanced armature drivers (full range, tweeter, woofer, and superwoofer drivers) in each earpiece. The earpieces are relatively massive for this reason, especially for an in-ear design, but the gunmetal-gray-and-silver metallic earpieces stand out with an undeniably high-tech profile. The buds are constructed from a high-strength magnesium alloy inner housing that holds the four drivers rigidly in place, with an assembly fitted into an ABS outer housing to suppress vibration.
Sony claims the XBA-4 in-ear headphones have a "noise-blocking" design and prevent sound leakage; I found the XBA-4's environmental noise-hushing abilities are about average for in-ear designs. At the very least, you won't have to worry about your music causing a disturbance to people around you.
The headphone cable is an asymmetric Y design, so the left branch of the cable is just 7 inches long compared to the right side's 21-inch length. As such, the headphones feel most comfortable draped over the left side of your body.
The cable's entire length measured from the left side is an ample 64 inches, but you can also wrap some of the cable around the supplied cord adjuster (a flat, black plastic spool) if you prefer a shorter cable. That's a good thing to prevent cord tangles while you store them in a bag or your pocket.
I don't usually have a lot to say about headphone plugs, but the XBA-4's right angle, 3.5mm, gold-plated plug is finished in glossy black and chrome and exudes class. The XBA-4 doesn't come with an inline microphone or a remote to control Apple devices; if these features are important to you, you can pick up the XBA-4iP for $20 more.
The headphone does, however, come with four sizes of silicone eartips and three sizes of noise-isolating tips. The "L" and "R" markings on the earpieces are fairly small and will be difficult to see in low-light conditions, but you should be able to find an appropriate size for your ear canal among the seven options. Achieving a proper seal is important to getting the best sound and the most isolation out of your headphones. Finally, Sony also includes a soft faux-leather travel case in the box.
The XBA-4 is a superb-sounding pair of headphones -- they offer a keenly balanced mix of deep bass, a natural-sounding midrange, and smooth treble detail. The ultimate test of any headphones is how they sound after long listening sessions, and the XBA-4s never left me fatigued. Beyond the sound, the earbuds are comfortable to use as well, though I was aware of the bulk of the relatively large earpieces hanging off my ears. That said, they felt secure, and never fell out without a significant tug. The cable was free of "microphonics," meaning it doesn't transmit any sound when it rubbed against my clothes. Finally, heavy distortion and loud volumes pose no challenge to the XBA-4s, and I found myself playing music at deafening volumes without fear of distortion.
I compared the XBA-4s to the Etymotic ER-4PT (single balanced armature) in-ears for contrast -- the XBA-4s presented a richer, fuller tonal balance with a more powerful dynamic slam with well-recorded drums, while the ER-4PTs gave off a brighter sound and superior resolution of fine details. On the other hand, I actually prefer the way the ER-4PTs reproduced the snare drums attack and the cymbals' sizzle. They're both good, but I felt the XBA-4s prevailed with a more accurate and refined sound.
I also compared the XBA-4 headphones with the Audeo PFE 132 in-ear (single balanced armature) headphones. The XBA-4s had better bass and came off more dynamic and noticeably fuller-sounding than the PFE-132s. Additionally, the acoustic guitars sounded more realistic using the PFE-132s, with the XBA-4s blurring the sound of each note together.
All of the above listening tests were conducted with my iPod Classic, but I also used the headphones to watch a few movies on my computer. Paired with a FiiO E17 headphone amplifier, the XBA-4s sound even more spacious than with music, and add a deeper audio layer to the theater experience.
Sony's first foray in audiophile-quality, balanced armature headphone design is largely successful, and the XBA-4s sound excellent -- if you can swallow the price tag, you'll enjoy their sexy design and rich sound.