Sennheiser

HD820

Flagship closed back headphones

$3499 RRP

When it comes to high-end closed-back headphones, the choices are surprisingly slim.

There will always be the titans of this genre, such as the Fostex TH900 MK2 ($1,999 RRP), the Audeze LCD-XC ($2,899 RRP), and the MrSpeakers Ether C Closed ($2,799 RRP). These have been the go-to flagships for the past few years.

Sennheiser has reigned supreme in the open-backed headphone game for decades, starting with the Sennheiser HD414 back in 1968. Since then, they have released several industry-leading open-back flagship headphones.

The HD800 was, of course, the 'go-to' for over a decade, being superseded only by its successor: the HD800S. Now in 2018, the team at Sennheiser are finally having a crack at the closed-back high-end headphone.

And there's a new king on Sennheiser's throne: The HD820.

Coming in at a nail-biting $3,499 in Australia, this is a price bracket that can only be described as “the upper crust” of the headphone market. It rivals the HiFiMAN HE-1000 V2 ($4,399 RRP), Grado PS2000e ($3,499 RRP) and Stax SR-007 MK2 ($3,699 RRP).

It’s an ambitious release, but how does it stack up?

Packaging and build

Unboxing any Sennheiser flagship offering is always an incredibly luxurious experience, and the HD820 delivered this in spades.

Inside the cardboard box is a case made from solid wood which is lined with fine silk. Upon lifting the lid, the HD820 headphones can be found slotted in snugly into a custom fitted mould, surrounded by three different options for cables: a standard 6.35mm, a 4.4mm balanced Pentaconn, and a 4-pin balanced XLR.

Upon removing the HD820 from the box, you're alarmingly met with a bright red sticker across the cup of the headphone, which reads: “ACHTUNG GLAS! NICHT FALLEN LASSEN!” which in (the also printed) English translation reads as “Glass! Handle with care! Do not drop!”

Wait ... Glass?

Sennheiser's HD820 bares a similar build and aesthetic to the HD800S, but instead of being an open-backed headphone, it uses has a solid sheet of custom-made curved Gorilla Glass covering the driver on each side of the cup to make it closed. This glass sheet looks and feels impossibly clean and is both endearing and unique.

The pads have received a decent upgrade, too. They are now much thicker and juicier, with an added ring of leather around the outside to give a little more distance between the ear and the driver, which is said also to increase sound isolation.

The rest of the headphone doesn’t disappoint, either. I was partially expecting the physical housing to be similar to the HD800S, but the differences between the two are quite distinct. The HD820 has a more rounded, muscular and bulky aesthetic, with a darker colour scheme consisting of black and blacker. 

This added bulk, combined with the weight (360 grams, compared to the HD800S 330 grams), creates a hefty, solid feeling headphone. It’s certainly not too heavy, but it’s heavy enough to feel like a solid, high-quality piece of German engineering - which it is.

The HD820 looks and feels just like a ludicrous European supercar, and I absolutely love it. It’s bold, refreshing and unique.

Inside the headphone

At CanJam NYC 2018, Axel Grell, Portfolio Manager at Sennheiser, spoke excitedly at length about the science behind this new closed-back model. From the use of the famous Helmholtz absorber to the individual enclosure size, shape and material choices, it’s clear that the engineering team at Sennheiser have thought about every single tiny detail.

While it’s ultimately unclear if the HD820 shares the same drivers with the HD800S, there is plenty of speculation within the Head-Fi community to suggest the drivers are the same. When looking at measurements comparing the two, it’s easy to see the similarities. However, there is a stark contrast in the 200Hz to 400Hz region. Axel addressed this in his speech, indicating that it is a deliberate tuning to accommodate for resonant frequencies inside the enclosure.

It’s also worth noting that other closed-back headphones such as the Beyerdynamic DT770 and the Sennheiser HD598CS also have this same frequency dip.

With the same impedance of 300 Ohms as the HD800S, it’s easy to believe that these drivers may indeed be a reworked version of the favoured classic, but perhaps time will tell if this is true or not.

The use of Gorilla Glass as a material in the cup is unique, and the sheets of glass were custom made specifically for this headphone. They were engineered and designed in conjunction with the engineering team at Sennheiser and have been finely tuned for their acoustic properties.

The HD820, as expected, is an absolute technical marvel. Kudos to Sennheiser for once again raising the bar in this department.

Using the headphone

Wearing any Sennheiser flagship is always a memorable and exciting experience. The way that the headphones wrap around your ears is unlike any other product on the market and is exquisite.

The HD820 takes this experience to the next level. The leather wrap around the outside of the pad increases both the size and density of the pad, giving superior isolation compared to its predecessors. The pads feel chunky but supremely comfortable. I much prefer these to the HD800S pads, and I hope there is some way of buying and fitting these new pads onto my old pair!

The isolation level offered by the HD820 is more than adequate. When worn, the headphone cups form a perfectly sealed enclosure around the ears. Outside noise has no chance to compete with music, as it now must compete with the Gorilla Glass, the thick leather-wrapped pads and the considerable plastic cups which bind them all together.

The choice of three cables makes it very easy to customise your amplification choices. However, I would strongly recommend listening to this set of headphones with the Sennheiser HDV 820.

The HDV 820 is the new flagship amplification system from Sennheiser and includes balanced and unbalanced analogue and digital inputs, as well as support for DSD. It shares its namesake with the HD820, and this is the first clue into the pair being a match made in heaven.

The good news though is when using the HD820 outside of their comfort zone with other amplifiers, they don’t bat an eyelid. Using them with an OTL amp made them sing with ease, and they didn’t buckle as a result of the impedance mismatch. They were also driven admirably from smaller unbalanced sources, such as the Matrix Quattro amplifier.

Sound

Coming from the HD800S, I thought I had a pretty good idea of what to expect. But, even when I thought I knew what I was in for, I still found myself pleasantly surprised.

The first song I chose for my testing was AleeFee by Andhim. I was immediately taken back by the sheer viscerality and detail of the low-end. The sub-bass delivers waves of impact, all the way down to 80hz, where it gently rolls off from there. It’s not a head-rattling experience; it’s an intoxicating smooth and linear response that comes across with both authority and accuracy but doesn’t detract from the rest of the mix in any way at all. Instead, it takes a complimentary position just behind it.

After the wild ride of the first track, I slowed the pace down in an attempt to retrieve as much detail as possible. Meet You In The Maze by James Blake was the track of choice, and the HD820 was able to keep up where other headphones have failed before: the vocals in this song are so layered and detailed that it can often become a jumbled mess with lesser headphone drivers. However, the sheer speed and attack of the 300ohm driver effortlessly cut through these sections like butter, and with knife-point precision. There is a reason why the HD800 series is so famous amongst the audiophile crowd; unrivalled extreme details and soundstage.

So, at this point, I thought to myself “we have fantastic bass and an incredibly layered and detailed mid/high response. What’s the best way to throw it all together?”. The answer was No Reason by Bonobo and Nick Murphy. The reverb vocal tails in this song are often difficult to detect on other headphones but are clear as crystal on the HD820. The light plucks of the instruments, as well as the gentle, subtle clicks scattered throughout the song are all perfectly audible as well. Accompanying all this ambient pleasantness, there's a thumping bassline which drives its way through the sub-bass range, and peeks into the midbass region, all of which are both felt and heard with the HD820.

HD 800S Comparison

Physically, they are surprisingly different. The HD800S feels very familiar to the original HD800 in hand, whereas the HD820 feels more like a closed headphone, with a little more heft (30 grams according to spec sheet) and are more circular.

When comparing the sound directly, it's easy to tell that these were cut from the same cloth: They are incredibly similar. Apart from the obvious differences in isolation and resulting soundstage, they are very much alike, which is indeed a win in my books.

In terms of sensitivity, they are the same to my ears. No volume adjustments were necessary when switching between the two.

After listening to a few albums with the two, I can conclude that the HD820 indeed feels like a “closed back” version of the HD800S with upgraded pads and more cables which is funny, because that's effectively what it is.

The one thing that I found a bit difficult to wrap my head around was the giant dip in the 300hz area. It’s clearly audible, and being so used to the HD800S, this requires an adjustment period to get used to.

Conclusion

If you’re in the market for closed-back flagship headphones, your decision just became a lot more difficult. The asking price for the HD820 is dizzyingly high, but in my opinion, the detail and soundstage are unrivalled by any other closed-back headphone offering.

If you’re coming from the HD800S, fear not. The main reason you would consider upgrading would only be to convert to a closed-back headphone, and if that's your aim, you can do so with confidence.

Sennheiser's first foray into the closed-back high-end headphone market with its HD820 is a complete success and well worthy of StereoNET's Applause Award.

Specifications

• Impedance: 300 Ohms
• Frequency response (Headphones): 12 - 43800 Hz (-3 dB), 6 - 48000 Hz (-10 dB)
• Sound pressure level (SPL): 103 dB at 1 kHz, 1V
• Ear coupling: around the ear
• Jack plug: 6.3 mm / Pentaconn / (XLR4)
• Cable length: 3m
• Weight: 360 g without cable
• Transducer principle (headphones): dynamic, closed

For more information visit Sennheiser.

Further reading: Headphones Discussion Forums