Early in my quest for high res digital music I’ve decided to purchase a Sony XBA-A3 to replace my Etymotics ER4, which was great in the mids but I felt lacking at the bottom. As I read up on various forums, Sony’s design got my attention. The Sony XBA-A3 is not your typical 3-Driver design. It uses 2-Balanced Armature (Highs and Mids) and a 16mm dynamic driver for the bass. The unique thing about their design is found at the crossover or rather lack of one. The XBA-A3 follows a similar design as the 1960’s Altec driver based speakers I use with my 2-watts Single Ended Triode amps. There is no abrupt cut off in the frequency but rather a gradual dip on the curve. I’ve learned this implementation from acclaimed designer Joseph Esmillia of JE Labs website. Indeed the XBA-A3 has a very full bottom and warm midrange presentation. Vacuum Tubes come to mind. Shimmer at the high frequency is also very good. Replaceable cables are cool feature too. Sony will have them on exhibit, along with other High Res gear at the November Hifi Show 2015. I suggest you try them before you decide to purchase your next IEMs.
I am glad Sony has decidedly returned to High End audio which they stop doing after the late 1980’s. Welcome back Sony. We’ve been missing you a lot.