Sony MDR-Z7 High-Resolution Audio Headphones. Sony's flagship headphones reproduce subtle high frequency sounds up to 100kHz – a first for headphone technology. With 70mm HD drivers featuring Liquid Crystal Polymer diaphragms, and a full metal design, you get the clarity you need to enjoy High-Resolution Audio – for music that takes you closer to a live performance. Discover true sound with all the emotion and energy of the original recording. A huge 70mm HD driver powers through your music, keeping every note precise, even at higher volume levels. And buy this Sony MDR-Z7 High-Resolution Audio Headphones - with 70mm HD Drivers & Liquid Crystal Polymer Diaphragms Now £549.00.