Billie Jean is the latest collaboration of In-Ear-Monitors (IEMs) between Astell&Kern and Jerry Harvey Audio. Featuring a new Dual Balanced Armature (BA) driver system and patented freqphase™ technology, Billie Jean is equipped with an internal sound bore design that brings clear, impeccably balanced sound, resulting in a real audio experience that will take your music to the next level.The new IEM shell has been optimized to fit nicely in the ear, while the 2-Way 2-BA design brings more power with less weight for efficient, yet powerful sound. The cable itself is manufactured from compressed, silver plated copper wire, which is then flattened and rolled into a steady interval and wrapped around Kevlar. This provides the cable with astounding tensile strength and delivers the full dynamic range of music. Conventional straight cables do not handle the frequent bending of cables and often short out, but Billie Jean’s intertwined cable disperses the stress to the cable to offer enhanced, long lasting resilience.