The new HD 660 S lets you enjoy sophisticated audiophile sound in even more listening situations. The successor of the legendary HD 650 excels with the improved performance of its new transducer design. Thanks to its lower impedance, it delivers reference-class sound also when connected to hi-res mobile players, thus offering much greater versatility. The HD 660 S is an elegantly designed piece of high-quality engineering that indulges the demanding listener with aural precision and great wearing comfort.
Sound for the passionate music enthusiast
Made for the demanding listener, the HD 660 S surpasses the exceptional performance of its predecessor, the legendary HD 650. With a crisp bass, excellent mid-frequency response, and a gentle, pleasantly natural treble, the HD 660 S has an expressiveness that immerses you in every emotion and nuance of music. Still, it always stays exceptionally accurate and transparent.
Cutting-edge Sennheiser technology
The HD 660 S features a new transducer design developed by Sennheiser. This results in improved control of the diaphragm movements thanks to a specially manufactured precision stainless steel fabric, which is adapted to the contour of the diaphragm. Extremely light aluminum voice coils ensure the highest impulse fidelity. The transducers are carefully selected and paired by hand to ensure consistently narrow (±1 dB) tolerances.
The HD 660 S has been created to enjoy music in supreme quality and from many different audio sources. Thanks to its low impedance it also offers reference-class fidelity with hi-res mobile players. Naturally, the HD 660 S reveals its full potential when it is connected to the balanced outputs of a dedicated headphone amplifier such as the HDV 820 or to the balanced output of a mobile digital audio player. Accordingly, it comes with a choice of cables for just about any occasion. All cables are made of highly conductive OFC copper, featuring very low handling noise and sturdy para-aramid reinforcement.
Designed for high-end comfort
Everything about the HD 660 S makes listening a pure pleasure – not least its strong yet lightweight open construction. The elliptical ear cups are shaped to follow the anatomy of the ear, while thick padding on the headband and the replaceable ear cushions guarantee hours and hours of listening in supreme comfort.
The look of sophistication
The pure and effortless sound of the HD 660 S is reflected in its new matte black and anthracite design. It is a high-end aesthetic that embraces both timeless elegance and contemporary style – uncompromising in its craftsmanship, like everything about the HD 660 S.
At quick glance, the HD 660 S may look like a modified HD 650 with HD 700 drivers transplanted inside of it, but that is where the similarities end. The HD 660 S offers the low-level detail characteristics that make the HD 800 so highly coveted among TOTL- and kilobuck-seeking audiophiles but with the HD 600's naturalness. In other words, remove the treble peaks that plague the HD 700 and, to a lesser degree, the HD 800, and retain the resolution of the HD 800 and you have the HD 660 S. Sennheiser has been removing the HD 650 from their site, and that alone suggests they have deep confidence in this new mainstream audiophile flagship product. I concur without equivocation, as I can see the HD 660 S easily inheriting the HD 650's throne to become the new go-to headphone among the community at large. In addition, I could see many of those who were less than thrilled with the HD 800's clinical sound (slightly withdrawn upper midrange and slightly boosted mid treble) going in ravenous droves after the HD 660 S. I really had to grasp at straws to find something negative to comment about these, and the only thing I could state is perhaps the retro looks may seen worn out or uninspired, but I personally am fond of this more classic, understated Sennheiser look over the gaudy Cyberman-like, space-age vibe of the HD 800 and HD 700. This is your atypical all-arounder with heightened technical abilities. Fast or slow, brash Bon Jovi or binotonous Beethoven, Sennheiser nailed this release with world-class expertise. Arguably, you could not do any better $999 and below. Amped and unamped, the HD 660 S is a force to be reckoned with, well-deserving of and highly recommended for a spot in the headphone stables of audiophiles seasoned and budding.
Hopefully this will settle the 600-650 debate -- the answer will be to just get this headphone.
Sennheiser once again showing why experience is more than important. The best choice was to bring this new technology from its transducers into an oval design that was, is and will be for a long time one of the best ever drawn. An oval design that Sennheiser hit on the headphones Orpheus, in HD 580, HD 600 and HD 650, these headphones hit with a very well designed and timeless minimalist design, which until now few or no rival got to hit this line of drawings, it is not enough to only have the quality sound if the design is not good. This design also inherited good headphones as the line HD 500. Sennheiser showed in these headphones that she is following the new era but without losing classicism and high sound quality. Anyone who has doubts about the sound quality of any Sennheiser headphones, know that the engineers explained and hit the description of each product on this Website, because who better than them to explain their own creations. Sennheiser - Single sound signature. Feel the life that music wants to pass.