This warm, inviting signature combined with extended sub bass makes listening uniquely pleasant and rewarding. And with comfort this good, it practically begs you to keep going for endless sessions. That’s how HD 660S2 combines the best of many worlds to give you an intimate experience you won’t want to live without.– Natural, relaxed, high-fi delity sound with extra sub bass: Optimized surround and dia-phragm with new voice coil with 300-ohm impedance – 38mm high-performance transducers built in Ireland: Steel mesh damping follows the driver’s geometry to control air displacement, while the magnetic yoke includes milled air vents for optimal ventilation, which minimizes distortion – Uniquely powerful vented magnet system for minimized distortion– Ultra-light aluminum voice coil with 300-ohm impedance for excellent impulse response– Intimate sound with great timbre and deep, accurate sub bass

Exceptional Comfort