Sennheiser HD 660 S2 Audiophile Headphones

Ever felt goosebumps from sound so real, it was as if the source was in the room with you? The non-fatiguing HD 660S2 gives people who love music an intimate way to connect more deeply with their favorite songs and artists. Breathtaking resolution and precision take you closer than ever to instruments and vocalists. Yet the sound is natural and balanced, never harsh or brash.

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.

Traditionally, audiophiles don’t get too excited about sub bass. It can easily get sloppy or boomy and become a distraction. And that’s a shame — because there’s so much more to experience here than just the gut punch of a kick drum. Did you know the low B of a 5-string bass vibrates at 30.9 Hz? Or that the lowest note on a concert piano comes in at 27.5 Hz? And of course, extended sub bass makes bass-heavy genres sound fantastic, too.

And that’s the magic trick here. In doubling the sound pressure at the very lowest frequencies, Sennheiser has nevertheless retained extraordinary precision and balance throughout the sub bass, mid-bass, and beyond. Most impressive is how this affects the listening experience. Extension on the low end changes everything — by creating more space for the sound. Against a deeper backdrop, highs feel more brilliant, the soundstage deeper, emotions stronger.

The velour earpads of the HD 660S2 can only be described as a tactile pleasure. With just the right amount of tension for proper acoustic positioning and supple padding, the headband won’t draw attention away from your music, either. As an open-back design, the HD 660S2 gives your ears an extremely comfortable climate, even for super-long sessions.

The low total weight and ergonomic headband rule out any potential discomfort on top of your head as well. Combined with excellent build quality made in Ireland, you’ll quickly grow attached to a listening experience that’s as physically pleasing as the warm, non-fatiguing sound at its heart.

As far back as the HD 580, high-end Sennheiser headphones have inspired generations with their balanced, natural reproduction. Recognized as benchmarks for neutral audiophile sound, the HD 600, HD 650, and HD 660S all share visible and audible DNA with the HD 660S2. The revised coil of the S2, for instance, now matches the 300-ohm impedance of the legendary HD 600 & HD 650. This new coil also provides higher magnetic force and electrical dampening for cleaner impulse response.

The surround is now more compliant, too, dropping the resonant frequency to 70 Hz. Considerable effort also went into optimizing the airflow around the transducer. There’s more sensitivity over the entire frequency spectrum because the magnet´s air gap works more efficiently now. Taken together, these measures result in even greater precision, speed, and resolution — with double the sound pressure at the lowest frequencies.