Sennheiser HD 660S2 review: New approach yields stellar results

The Sennheiser HD 660S2 is a polarizing headphone. It’s much less of an improve to the HD 660S than a very completely different strategy to the listening expertise in comparison with some other product within the firm’s vaunted 6XX line. And I dig it.

An open-back headphone has a particular use case, as a result of sound will inevitably leak into your listening atmosphere throughout playback. That’s by design, as that openness creates a wider soundstage for the listener. That additionally means they’re not good to be used in an workplace, on public transport, or subsequent to your companion in mattress. These are for solo listening solely.

The HD 660S2 has divided the audiophile headphone neighborhood, principally as a result of reviewers and message board commenters appear shocked by Sennheiser’s introduction of a very new sound profile to its line. When this mannequin is placed on the lab bench, measured, and in comparison with the usual sound curves, it reveals some shocking deviations which can be producing controversy within the hobbyist neighborhood.

James Barber/Foundry

One of many issues I get pleasure from concerning the Sennheiser model is that its gear appears to be tuned extra by people than by machines. From its Ambeo soundbars to its in-ear screens, I’ve at all times had the sense that there was an individual with particular tastes fine-tuning the audio system to create an expertise that displays particular person selections.

I’ve even discovered that to be true with the corporate’s reference headphones within the 6XX line. They is likely to be comparatively impartial, however they’re by no means mechanical. The HD 660S2 is decidedly not impartial, and that shall be an excellent factor for a specific kind of listener.

This evaluate is a part of TechHive’s in-depth protection of the best headphones.

What’s included with the Sennheiser HD 660S2

It’s value noting that Sennheiser has gone for minimalist packaging this time, which shall be both a determined enchancment over or a downgrade from the HD 660S, relying in your perspective. I’ll come down on the facet of enchancment, since I doubt anybody actually makes use of the bespoke picket field that comes with the opposite mannequin. The unboxing expertise is likely to be much less spectacular, however recyclable cardboard is best for the planet.

The HD 660S2 appears to be like equivalent to the earlier mannequin, besides the Sennheiser branding is now bronze as an alternative of silver. The development is usually plastic, except for the steel headband and grilles. A part of how Sennheiser conveys that they’re extra severe about audio high quality than luxurious is that at the beginning look, their 6XX-series headphones don’t look a lot completely different from any good pair of $200 cans. They’re solidly constructed, however they don’t announce themselves as luxurious items.

James Barber/Foundry

You get a 5.8-foot, 4.4mm balanced headphone cable; a 5.8-foot, 1/4-inch unbalanced headphone cable; and a 1/4-inch-to-3.5mm adapter. Sennheiser makes use of proprietary connections between cable and headphone, so you may’t swap both of those out for a third-party cable. Connecting the cables doesn’t yield a satisfying click on once they’re in place, so it’s greatest to take care when pushing them into the headphone’s earcups.

There’s additionally a carrying bag that gained’t present any vital safety except for stopping scratches. I took the HD 6602 on a street journey and spent a major period of time ensuring they weren’t getting crushed. Consider it as a storage bag versus a carrying case.

James Barber/Foundry

How the Sennheiser HD 660S2 is constructed

The HD 660S2 has 300 ohms of impedance, so that you’ll must ensure you have an amp that’s able to driving them. Every earcup has a steel grille that permits for max airflow to (and sound leakage from) the 38mm transducers (manufactured in Eire). The frequency response is 8Hz – 41,500Hz and the full harmonic distortion (THD) is rated at < 0.04% (1 kHz, 100dB).

James Barber/Foundry

You may see the construction of the inner framing if you look by means of the HD 660S2’s aluminum grille. Maintain them as much as a lamp and also you’ll notice which you could see mild coming by means of the froth on the within of the earcups. Open-back really means open right here.

The velour ear pads are comfy, however they’re not destined to final ceaselessly. As would be the case with virtually any audiophile headphone, you’ll want to exchange them after just a few years of standard use. The headphone itself is in any other case constructed to final for many years.

Listening to the Sennheiser HD 660S2

Whereas I used this pair with quite a lot of units over the previous few weeks, I did my important listening with Qobuz by way of an iFi Gryphon xDSD DAC plugged into an iPhone 13 Professional Max. In case you’re investing in a $600 pair of headphones, you’ll need to goal a bit larger than listening to Spotify or YouTube.

James Barber/Foundry

Listening to a 24-bit/44.1kHz stream of Oasis’ 1994 album Positively Possibly highlighted the strengths of Sennheiser’s strategy with these cans. When in comparison with the unique HD 660S, listening to “Stay Perpetually” with the S2 mannequin featured a much-improved soundstage for the drums, extra muscle within the rhythm guitars, and nice definition for the track’s myriad lead guitar elements. There’s a burr in Liam Gallagher’s lead vocals that’s not noticeable with the unique HD 660S. That burr is likely to be slight distortion launched by a slight dip within the audio ranges in Liam’s vocal register, however the impact is nice. Listening to guitar-driven rock was spectacular throughout the board.

In case you’re a classical music fan, the dialogue will get a bit extra difficult. Listening to a 24-bit/192kHz stream of the 1968 recording of Gustav Mahler’s Symphony No. 5 by the New Philharmonia Orchestra carried out by Sir John Barbirolli, the long-lasting trumpet solo that opens the primary motion has higher definition and element on the unique 660S, however the total soundstage is superior on the 660S2.

The dip within the higher mids that makes guitar-driven music slam so onerous and helps to fill out the low finish comes with a tradeoff: In case you’re listening to loads of music that’s principally acoustic or that emphasizes alto or soprano vocals, you may need to look to a unique headphone.

James Barber/Foundry

Once I first began listening to the HD 660S2, I felt as if that lack of element could be a giant challenge for me. As I’ve spent extra time with this headphone, I’ve come to understand the general strategy. As somebody who listens to music in all kinds of genres, I’d choose the HD 660S2 over some other headphone within the Sennheiser 6XX line.

I acquired persistently higher efficiency after I used the balanced headphone cable with the 4.4mm connector than I did with the 1/4-inch cable with the three.5mm adapter. It wasn’t an amazing enchancment, however it was ok that customers ought to ensure they use the balanced cable if their headphone amp helps that connection.

Is the Sennheiser HD 660S2 value $600?

At this value, a good portion of the marketplace for the Sennheiser HD 660S2 shall be headphone customers who personal a number of pairs and luxuriate in debating the trivialities of 1 tuning versus one other. That’s not how the overwhelming majority of listeners strategy selecting a headphone, so there’s loads of noise to chop by means of when contemplating a mannequin like this one.

I’d recommend that the HD 660S2 is probably the most musical of all of the headphones on this Sennheiser line; it’s a headphone designed to achieve a broader viewers than the corporate’s different fashions. It’s simpler to chill out and benefit from the expertise of listening to an album with the Sennheiser HD 660S2, versus listening and always analyzing how the headphone itself sounds.

That places the 660S2 in an attention-grabbing place. They’re the costliest within the 6XX line, however they aren’t constructed with the form of supplies that sign a luxurious buy for informal listeners. And in contrast to closed-back headphones, you may’t lug them with you all over the place and luxuriate in them with out annoying the opposite folks in a public house.

I’ll go as far as to match the present debate over the Sennheiser HD 6602 to the principally adverse reception that Weezer’s Pinkerton acquired upon its launch in 1996. Now thought of some of the influential LPs of the Nineties—and one of many band’s greatest, in case you ask followers—critics and most of the people heartily rejected the file on the time. As soon as the audiophiles recover from their preliminary shock on the strategy that Sennheiser took in designing the HD 660S2, I predict it’ll develop into some of the celebrated open-back headphones of this period.