Sennheiser HD 660S2: New approach yields stellar results

The German audio manufacturer abandons "neutral" tuning to design an open-back headphone that's great for immersive listening.

- JAMES BARBER

The Sennheiser HD 660S2 is a polarizing headphone. It's less of an upgrade to the HD 660S than a completely different approach to the listening experience compared to any other product in the company's vaunted 6XX line. And I dig it.

An open-back headphone has a specific use case, because sound will inevitably leak into your listening environment during playback. That's by design, as that openness creates a wide soundstage for the listener. That also means they're not good for use in an office, on public transport, or next to your partner in bed. These are for solo listening only.

The HD 660S2 has divided the audiophile headphone community, mostly because reviewers and message board commenters seem shocked by Sennheiser's introduction of a completely new sound profile to its line. When this model is put on the lab bench, measured, and compared to the standard sound curves, it shows some surprising deviations that are generating controversy in the hobbyist community.

One of the things I enjoy about the Sennheiser brand is that its gear seems to be tuned more by humans than by machines From its Ambeo soundbars to its in-ear monitors, I've always had the sense that there was a person with specific tastes fine-tuning the speakers to create an experience that reflects individual choices.

I've even found that to be true with the company's reference headphones in the 6XX line. They might be relatively neutral, but they're never mechanical. The HD 660S2 is decidedly not neutral, and that will be a very good thing for a particular type of listener.

WHAT'S INCLUDED WITH THE SENNHEISER HD 660S2