Hoved-fi

Sennheiser claims that The HD 660S2 mount a new improved transducer airflow and a refined voice coil's for a warm bass characteristic that pair perfectly with its silky-smooth treble performance and allowing the timbre of any instrument part to stand out across the entire frequency spectrum.

By reducing the voice coil's weight, impulse response improves, bringing hyper realistic textures to the forefront of any performance reproduction. The overall experience is smoother and warmer than the original HD 660S, thanks to that reduces the distances between select peaks and troughs.

The overall impedance matches now the HD 600 and HD 650, moving from 150 ohms to an audiophile-friendly 300 ohms, for a better dynamics and low distortion.