Sennheiser’s HD820 are superb, imperfect headphones like no other

For as long as I’ve been reading and writing about headphones, one thing has remained true: the very best cans have an open back. They leak music out to the world and let noise in, a necessary compromise to reduce reflections and resonances that could distort the sound. Closed-back headphones can be great, but they can’t match the expansiveness and transparency of their open brethren.

Sennheiser’s HD820 – its first go at premium closed-back cans – doesn’t destroy those dogmas, but it gets pretty darn close. Despite questionable decisions – that $2,400 price tag particularly stings – it sounds like nothing else I’ve heard.

A history lesson for those not in the know. The HD820 is essentially a closed-back variant of Sennheiser’s venerable HD800, and its refined revision, the HD800S.

The HD800 came out in 2009, and it remains one of the most recommended products on the market, known in particular for it’s huge, speaker-like soundstage, and remarkable transparency. You can find an HD800S for less than $1,000 used – an HD800, for even less – but they remain competitive even as the competition regularly crosses into $2,000+ territory. The Focal Utopia, for instance, cost a cool $4,000 at launch, but I consider them to be more of a ‘sidegrade’ than an upgrade.

Needless to say, hype was stratospheric when the HD820 was announced in January. Sennheiser promised to emulate or improve on the sound of one of the most-open sounding headphones in the world, in a closed-back design.

And what a gorgeous design it is. Subjectivity acknowledged, but the HD820 are the prettiest headphones I’ve used. They look a lot like a refined version of the HD800S, and I love the way the curved glass shows off the 58mm ring-shaped driver, which Sennheiser is so proud of it hasn’t changed it since 2009.

The headphone, despite its size, is remarkably comfortable. The earpads are more plush than its predecessors, and the headphone is light enough that I had no trouble wearing it for hours. The closed design is decent at blocking out external noise, and more importantly, lets little of your music out. I can use them late at night while my girlfriend is sleeping. I can’t say that for the vast majority of top-of-the-line headphones.

I’d almost call them portable if it weren’t for the huge size, giant cable, and the fact that you need a powerful amp for decent sound.

Because the drivers remain the same, HD820’s new acoustics have everything to do with its chassis. That glass is for more than just aesthetics – its curved design helps redirect sound emanating from the rear of the drivers into a dampening material, eliminating much of the detrimental resonance typically associated with closed designs (boomy bass for instance). This design also helps the HD820 achieve a wider soundstage than most closed-back headphones – although the gigantic earcups don’t hurt.

If the goal was to make the most open-sounding closed headphone – without any fancy software tricks like Audeze’s Mobius – I think Sennheiser succeeded. The HD820 sounds huge for closed-back cans. Heck, it sounds bigger than plenty of open-back headphones.

In particular, Sennheiser is able to create a rare sense of distance for headphones – like you’re sitting a row or two back at a performance rather than having musicians blasting sound right in your face. Focal’s Utopia ($4,000) and Clear ($1,500) both have a smaller presentation, despite their open design. Granted, Focal’s headphones are known for having a very intimate soundstage, but it’s a notable advantage for the HD820 nonetheless. I also think the soundstage is a bit more three-dimensional than Hifiman’s new Arya, which I had on hand during the last few days of testing.