The 64 Audio tia Fourté™ is a first-of-its-kind universal-fit earphone that takes full advantage of the patent pending tia™ system and everything we’ve learned up to this point in designing world-class in-ear monitors. The earphones are machined out of a solid piece of aluminum for a durable yet elegant look with beautiful copper patina finish inlayed on the faceplates. Inside, proprietary tia open balanced armatures are expertly arranged to deliver rich, natural sound in a brand new way. Featuring ground breaking technology such as frequency-shaping acoustic chambers in combination with an internal passive radiator that help to craft a visceral low end, smooth mids, and a luscious 3D soundstage. Get ready to hear detailed highs like you've never experienced before thanks to a custom open balanced armature tia high driver. Additionally, internal apex™ technology helps to vent air pressure from inside the ear canal for fatigue-free listening. We broke all the rules and started from scratch to come up with the tia Fourté and still managed to fit this ground breaking technology into a shell that's smaller and more ergonomic than our Universal-Fit 12 driver model.