The ATH-M60x Professional Monitor Headphones from Audio Technicia feature a classic closed-back, on-ear design. With 45mm large-aperture drivers, interchangeable cables, wide frequency response, superior comfort and durable materials, the M 60X is an excellent choice for studio, broadcast and field applications. 45mm Large Aperture Drivers Large-aperture 45mm Neodymium magnet drivers and copper-clad aluminium wire voice coils deliver exceptional clarity throughout the frequency range with a deep and accurate bass response. The coils provide an extended frequency range of 15 Hz to 28 kHz making sound clearer and every note distinctly audible. Low Impedance Design With 38ohm impedance, the headphones are designed to be loud enough when attached to low powered devices such as mobi.