Ultrasone has released its latest headphones, and the first it offers with an open-backed design as well as in more than one version. The PRO 2900 can be had as a standard, single-cable version and a balanced, double-cable version built to provide a "transparent" quality that avoids excess bass or treble. The Balanced set is paired with a balanced amplifier to boost performance by doubling the slew rate and voltage swing power.
