Astelle&Kern’s $1,299 AK T9iE in-ear-monitor headphones are as beautiful as they are expensive. They’re tuned specifically for pairing with the company’s stellar high-res digital audio players. If you own one—or you just value high performance and beautifull craftsmanship—you’ll want to give these gems a serious look and a long listen. A&K’s T9iE headphones are jointly designed and voiced by Astell&Kern and legendary German headphone manufacturer, Beyerdynamic. Each headphone is handmade in Germany. The AK T9iE succeed the AK T8iE, which were also made by Beyerdynamic for Astell&Kern and are sold by Beyerdynamic as the Xelento. The AK T9iE follow Astell&Kern’s hallmark industrial design that plays with shapes, angles, and lighting. The headphones have a PVD coating that will reflect light differently and reveal different shapes depending on your viewing angle. Under the hood, the T9iE feature Beyerdynamic’s Tesla driver technology. Tesla technology refers to a series of measurements, design, and materials that Beyerdynamic says improve the headphone’s sound and efficiency. Beyerdynamic reserves its Tesla technology for its reference headphones. The headphone...