Introducing Billie Jean, the latest collaboration between Astell&Kern and Jerry Harvey Audio. Billie Jean features the patented freqphase® technology from Jerry Harvey Audio with a new internal sound bore design to bring clear and impeccably balanced sound from sub-bass to brilliance range. The new IEM shell has been optimized to fit nicely in the ear, utilizes a 2-way 2-BA design, Silver Tinsel cable and L-type plug in a small, compact package. The result is a brilliant pair of IEMs designed and built by Jerry Harvey, the inventor of custom-IEMs, and Astell&Kern, the global leader in Hi-Fi audio. Pre-orders start today and ship in May 2018. https://us.astellnkern.com/collections/headphones-iems/products/billie-jean Billie Jean will make its official debut at the 2018 Fujiya AVIC Spring Headphone Festival in Tokyo, Japan. The Dual BA drivers in Billie Jean have been carefully tuned with the patented technologies of Jerry Harvey Audio including Freqphase™ and Time | Phase Waveguide. Jerry Harvey, an audio engineer himself, brings the full range of dynamic sound from high to low range in this new IEM. A new Acoustic Chamber Sound Bore opens up the higher notes and lets them shine even more by controlling the air movement volume in the ear pieces. This also prevents any artifacts in the sound production. The earpieces in Billie Jean are about 30% smaller in size than the Michelle Limited. Extensive studies have been conducted to explore the different shapes and sizes of ear carnal of users in a range of different ages. The result is a smaller shell that fits more comfortable and is stable in the ear. The included cable is made of a mix of Kevlar and Tinsel wire for better sound and durability in day-to-day use. A L-shaped plug also prevents any short or weak connection issue. Billie Jean is $349 USD and starts shipping in May 2018.