Closed-back, oval over-ear design offers superior isolation, improved low-frequency response, ergonomic fit Largest-in-class, titanium-coated 50mm transducers with pure OFC voice coils Engineered to match AKG’s Reference Response curve acoustic target for accurate, neutral sound. Features: Best-in-class frequency response: 5 Hz to 40 kHz, best-in-class sensitivity: 114 dB and optimal 32-ohm impedance to supports a range of sound sources