It’s been nearly 10 years since HIFIMAN launched the Legacy HE500: the last pair of “classic” HIFIMAN headphones. Like other models in the HE500 Series, the Legacy featured a dual-sided planar magnetic design, which used magnets on both sides of a membrane to generate sound waves. This led to unrivaled sensitivity, but also extra weight. Newer single-sided magnet designs slimmed things down; but for many enthusiasts, something in the sound was lost. In the HE5XX, that sound is back—with improved clarity, and without the weight. Thanks to stronger double-sided magnets, 2-micron-thick Nano Diaphragm membranes, and other careful design adjustments, the HE5XX is 30-percent lighter than the Legacy HE500. What’s more, these same components (plus a newly designed conductor layer) greatly increase the efficiency of the HE5XX, making it easier to drive. For those that want to push to performance even further, the HE-5XX is also wired to work with a balanced cable.