Sennheiser launches the latest generation of its HD 600 audiophile headphones

Sennheiser HD 660S2 over-ear headphones
(Image credit: Future)

Sennheiser has designed its fair share of classic headphones over the years starting with the number ‘6’. The HD 600 and HD 650 both fall into this category, but will its new HD 660S2 be one we can look back on in a few years with a similar sense of fondness?

As part of the design process for these new audiophile headphones, Sennheiser has listed to feedback from customers who own the previous HD 660S model, taken it onboard, and used it to help shape the sound quality of the HD 660S2.

And the result, according to Sennheiser, has been an upping of the ante in terms of detail, dynamics and bass. How? Sennheiser has implemented a number of design tweaks, including improving the airflow around the 38mm driver via a new vented magnet system. It has been designed this way to reduce distortion and help deliver a more dramatic and dynamic listening experience. The HD 660S2 also use a lighter aluminium voice coil than the previous generation, while impedance matches Sennheiser’s HD 600 and HD 650 models at 300 ohms.

Exploded diagram of Sennheiser HD 660S2 headphones

(Image credit: Sennheiser)

“With precision and power like no other and new sensitivity across all frequencies, listeners will hear details they’ve never heard before, especially at the lower end of the spectrum,” said  Jermo Koehnke, Sennheiser Audiophile Product Manager.

 The design features plush ear cushions, an eye-catching jet-black finish and bronze accents. Being open-back, you’ve also got outer mesh grilles which allow you to peer into the inner sanctum of the headphones.

In the box, you get a storage pouch and two 1.8m (5.8ft) detachable cables, one with a 6.3mm single-ended stereo plug and the other with a 4.4mm balanced plug.

The Sennheiser HD 660S2 are available to pre-order now and go on sale on the 21st February for £499 (€599 / $600).


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Andy Madden

Andy is Deputy Editor of What Hi-Fi? and a consumer electronics journalist with nearly 20 years of experience writing news, reviews and features. Over the years he's also contributed to a number of other outlets, including The Sunday Times, the BBC, Stuff, and BA High Life Magazine. Premium wireless earbuds are his passion but he's also keen on car tech and in-car audio systems and can often be found cruising the countryside testing the latest set-ups. In his spare time Andy is a keen golfer and gamer.

  • Jasonovich
    The HD 6XX were my preferred choice until I started hearing rave reviews of Hifiman Edition XS from various independent sources, and I was sold, when I managed to purchase the planar magnets £80 less than the retail price.
    I'm still running in my my Hifiman Edition XS. These are incredible headphones, the expansive sound from planar magnets are like none other. The basslines are really defined without it smothering the treble. The treble is forward sounding without being harsh. Lovely clear, transparent midrange also. When I was listening with my old dynamic headphones the obscure details in the background, which were there if you homed in your ears, became much clearer with the Edition XS. I think these are possibly the best headphones you will find under £1000.