The open over-ear design offers the expansive soundstage you'd expect from a top of the line headphone. Deep, extended bass, a smooth midrange, and warm highs pair together seamlessly to offer a musical and engaging experience for the listener. With an impedance level of 70 ohms at 1 khZ and a sensitivity rating of 101 dB SPL/V, you're going to need an amplifier to hear these headphones at their best.