Sony XBA-3

I personally appreciate Dan Herman for giving me an opportunity to analyze this IEM. Thank you, Dan!

Sony XBA-3 is one of Sony's very first IEM models equipped with their own proprietary balanced armature drivers. Since the development is vital for Sony's future IEM production, 投野耕治-san, a deputy general manager of Sony Electronics in Japan, who is also the master of Sony's MDR-series, takes charge of the entire development process.

And eventually, 投野-san comes up with total of four XBA models: 1, 2, 3, and 4.

The model names represent the number of drivers each of the products are equipped with, and the manufacturer's data indicate sound quality goes up as the number of drivers increases. As XBA-3 is equipped with triple drivers that cover the entire audible frequency range, it should have a good linearity in frequency response along with extended bandwidth up to 20 kHz.

"The ability to combine woofer and tweeter drivers in addition to the standard full-range driver, would also greatly appeal to music lovers seeking an even more intensely satisfying listening experience, with bass and treble frequency ranges reproduced in even higher-fidelity."

http://www.sony-asia.com/pressrelease/asset/469743/section/regionalpressreleases

 

 

PRO: Very low distortion for balanced armature drivers. As Sony's proprietary BA drivers' directionality of acoustic transduction is on-axis, unlike that of conventional balanced armature drivers, no phase shift can be observed.

CON: Impedance characteristic is not linear at all, which indicates a need for low acoustic output impedance source for consistent damping. Also, the peak at 4 kHz is residual, and is also quite audible.

ON SECOND THOUGHT #1: Deep insertion is not recommended for Sony XBA-3. Once the insertion depth gets closer to the reference plane, the high frequency goes out of control, leaving a very sharp peak at  ~13 kHz. This is possibly due to lack of Sony's tuning expertise, as this is one of their very first IEMs with balanced armature drivers installed.

ON SECOND THOUGHT #2: The overall tonality becomes more linear, but the resonance at 4 kHz becomes quite problematic when under-damped.

ON SECOND THOUGHT #3: A simple damper yields about 2 dB of attenuation, while a microfiber cloth does slightly more than that.

ON SECOND THOUGHT #4: It is extremely interesting that the frequency response of XBA-3, which was introduced in November 2011, closely resembles that of MH1, which was released in August 2011. Is it possible that the designer of XBA-3, 投野耕治-san, used MH1, which was developed by Sead Smailagic of Sony Mobile in Sweden, as a reference, or perhaps they share the same reference target? The target is almost identical, though MH1 is slightly wider in frequency range bandwidth.

ON SECOND THOUGHT #5: This is my recommendation to Sony XBA-3 users. Such configuration shall give the IEM little more linearity, while keeping its tonality intact.