Sennheiser HD820 – Closed Dynamic Headphone Review

Pros: Imaging, sound-stage, tonal balance, clarity, bass extension, versatility, build, comfort

Cons: Price, cable relatively heavy, prone to twisting, isolation not great for closed headphone


Three years ago, I took part in an Australasian tour with the HD800S. I was so impressed with that headphone, that I ended up buying one for myself soon after. It managed to satisfy my preferences in a way that no other open headphone has. It remains my primary headphone, and to be honest I’m not really looking for another one now.

One of the few issues I have with the HD800S has to do with my personal situation. The HD800S is very open. And my wife and I share the lounge in the evenings – she generally watching TV, and me either working or listening to music. At times I’ve really wished that the HD800S had a closed equivalent. Someone at Sennheiser obviously thought so too – so today we’re looking at theHD820 closed headphone. Will it capture me the way the HD800S did?


I’m not going to go into too much detail in this section – because I’d imagine practically everyone must know who Sennheiser is. The company was formed in 1945 by Fritz Sennheiser and seven fellow engineers, and their first product was actually a voltmeter. In 1946 they built their first microphone, and by 1955 the company had grown to 250 employees. As the company grew, so did their product range, and in 1968 they have been credited with introducing the world’s first open headphones. Sennheiser has been a pioneer in high end audio, always pushing the boundaries, and several of their products have reached legendary status over a number of years – especially the incomparable HD600 and HD650 (still popular almost 2 decades on), the HD800/S (widely regarded as one of the World’s best dynamic headphones, and of course the Orpheus (1 & 2) – statement electrostats built with no budget restraints and designed to be the best headphone the world has experienced.

Sennheiser now has more than 2700 employees globally and an annual turnover of almost 700m Euro. Not bad for a company that started from such small beginnings just 70 years ago. And the vision that drives the company is still as strong today:

We are shaping today the audio world of tomorrow – that is the ambition that we and our company live by from day to day. This vision statement describes what we are hoping to achieve together. The foundation for this is our history, our culture of innovation and our passion for excellence.


I was provided with a tour review sample of the HD820 by Sennheiser and facilitated by Jensy for the purposes of review. I am not affiliated with Sennheiser in any way, nor do I make any financial gain, and this is my honest opinion of the HD820 after a couple of weeks with them. The HD820 will be returned next week to Sennheiser.


If you haven’t read any of my reviews, I suggest starting here, as it will give you an insight into my known preferences and bias.

For the purposes of this review – I’ve used the HD820 from a variety of devices including (among others) the FiiO M11, my iFi iDSD, and the VE Enterprise Tube amp. I also tested them portable but amped (using the Q5, and XRK-NHB).

In the time I have spent with the HD820, I have noticed no change to the overall sonic presentation (break-in). This is a purely subjective review – my gear, my ears, and my experience. Please take it all with a grain of salt – especially if it does not match your own experience.


The Sennheiser HD820 (like others in the 8xx range) come in an unmistakably Sennheiser box, consisting of an outer printed box over an inner protective case. The outer box measures 340 x 400 x 150mm, is corrugated cardboard, and is a mixture of the Sennheiser light blue combined with some grey scale photography of the HD820.

Opening the outer box reveals the inner case, which is essentially a well padded internally hinged lid hard case. Also revealed are the comprehensive manual and USB key which has an electronic copy of the authenticity certificate and frequency response, and also a full electronic copy of the manual. The manual also contains full specifications and other information (in multiple languages) about the HD820.

The HD820 is safely nestled in a form fitting foam enclosure. There are 2 balanced cables inluded with this demo model – a 4.4mm Pentaconn as well as the more traditional XLR termination. Also included is the standard 6.3mm single ended cable.



USD 2299 (Amazon


Circum-aural closed dynamic stereo headphones


56mm ring radiator transducers

Frequency Range

12 to 43800 Hz (-3 dB), 6 to 48000 Hz (-10 dB)

Nominal Impedance

300 ohm

SPL at 1kHz

103dB (1 Vrms)


< 0.02% (1 kHz, 100 dB SPL)


360g (headphones only)

Cable Material

Silver plated OFC, balanced, shielded, para-aramid reinforced 3m

Cable – Termination

Three – 1 x 6.3mm SE, 1 x XLR 4 bal., 1 x 4.4mm Pentaconn bal.


Unfortunately I have no way of properly measuring the HD820 – my measuring system is only designed for IEMs, and I have no way of measuring with an artificial ear. I have been able to comparatively measure my HD800S and the HD820 so you can see the differences (below). This is without a Pinna (ear) adjustment, but can be used for comparative data (same rig and set-up conditions).

For a better view of a properly calibrated response, along with a comparison to both HD800 and HD800s, I recommend visiting Head-Fi and viewing Jude’s measurements on his Gras set-up – here 

The graphs are provided merely as a point of discussion, and later in the review I’ve included a subjective comparison to the HD800S.


The overall look of the Sennheiser HD820 (which is a continuation of the HD820S) could be described as futuristic, perhaps slightly sci-fi, but always distinctive. I know people who regard it as a bit pretentious, and others who love the unmistakable design. I fall very much in the latter camp – and the one thing I always liked about my own HD800S was how good the black looked. The HD820 frame is again in black and to me it looks great.

The build for the HD820 is very similar to the HD800 and HD800S. The headband assembly consists of a 22mm width of sprung stainless steel which has the serial number and model designation engraved in it. This sits atop a 45mm wide and 10mm high padded underside with microfibre covering. It is very soft and very comfortable, and for me has good weight distribution. The layered metal and plastic construction is especially designed to dampen or attenuate vibrations to the ear-cups – so that the drivers are completely isolated from unwanted distortion.

The extenders are a special polymer initially developed within the aerospace industry, with the sole purpose of contributing qualities of high strength and at the same time light weight. The yokes are made from the same material, and are hinged to allow the cups to swivel on 4 axis. I have no problem adjusting quickly and easily for a very good seal.

The cups themselves are D shaped, with the ear-pads well padded. Here there is a difference to the open backed HD8xx models. Whilst the overall shape is the same, and the main face is still micro-fibre, the outer walls are synthetic leather, and the pads are noticeably deeper. They measure externally 120mm high and 115mm wide at the outer pads. Internally the pads have 75mm of available height and 60mm of available cavity with a depth of approximately 30+mm, so my ears never come close to touching either the edge of the pads or the protective mesh over the transducer.

The transducer is 56mm (the same as the rest of the HD8xx family), is a ring radiator design, and is encased in stainless steel for further dampening of unwanted vibration. And it still employs Sennheiser’s absorber technology which is designed to absorb resonance so that bass will not mask higher frequencies, and also prevents any higher peaks in the lower treble. The inner cup is also designed so that sound waves will enter the ear on a slight angle to enhance the perception of spatial awareness, and create a more natural 3D sound. 

The outer cup is made of the same high grade polymer, with an inner fine black mesh, but this time it is closed. There is a black honey comb mesh directly over the drivers for protection and ideal airflow.  The biggest difference is of course the addition of the Gorilla glass sealing the rear of the drivers.  Sennheiser calls the combination an acoustic diffraction housing, and the convex G-glass is designed to control sound wave reflections and direct them in a controlled manner to the ring shaped absorber elements situated around the transducers.

Each of the yokes has a left and right designator printed in silver on the rear, and adjacent to this is the cable socket.  These connectors are a barrel type and consists of a single male plug (on each side) with two recessed pins, which fits perfectly into a slotted receptacle socket on the HD820. When mated, they fit extremely firmly together.

The cables are 3m long (there are three of them), and utilise silver plated copper wiring which is in balanced configuration (separate signal and ground for each side). The wires are then shielded and covered with a para-aramid outer sheath (so it is either Kevlar or Twaron fibres) which provides and exceptional strength to weight ratio. There is extremely good cable relief at both the earphone connectors and at the single-ended, Pentaconn 4.4mm or XLR jack. The only concern I have with the cables is the unsheathed portions between the Y split and headphone connectors.  While these are in perfect condition now, my HD800S cable has already started to perish in this area – necessitating purchase of an after-market cable.  This appears to be a common flaw, and One which disappoints me given the cost of the headphone.

Overall though, the build on the HD820 is exceptional, and I can’t see any real flaws.


I’ve already covered the cup dimensions and covering, and they are quite possible the most comfortable headphones I’ve worn. I do wear glasses and there is a slight clamp force (while by no means excessive) which does force my glasses onto the bridge of my nose. If I take the glasses off, the comfort is quite simply amazing – good distribution of weight, really soft pads, and the sort of headphone I can quite literally wear for hours. The answer to the glasses issue is of course adjustment, and if it was my own pair – I’d be also trying to slightly relieve the clamp force (gentle stretching).


Definitely better than the very open HD800S, but I can still hear outside noise, although this diminishes rapidly with music playing. My wife tells me that they don’t externally isolate perfectly either. They are better then the HD800S, and she really appreciates the drop in external sound, but they at times seem more semi-closed than fully closed.


The following is what I hear from the HD820. YMMV – and probably will – as my tastes are likely different to yours (read the preamble I gave earlier for a baseline). Most of the testing at this point (unless otherwise stated) was done with my iFi iDSD (DAC) and VE Enterprise (amp).

For the record – on most tracks, during my listening evaluation the volume level on the HD800S measured at the ear was around 60-70dB A-weighted. The room was fairly quiet, and I simply had no reason to add more volume (there was enough clarity definition not to look for any more volume). Tracks used were across a variety of genres – and can be viewed in this list


  • Sub-bass – well extended, and able to stretch to low frequencies in a sine sweep. Slightly recessed comparative to mid-bass, but enough presence for rumble, and very good impact.

  • Mid-bass – elevated compared to sub-bass and lower mid-range, but a natural sounding hump which doesn’t sound boomy or over done. No bleed into mid-range that I notice, and speed is very good. Impact is reasonable. Adds some warmth to the overall signature – but again very natural sounding.

  • Lower mid-range – sounds reasonably balanced to me (which is good), and I found this quite strange when I considered the 300 Hz dip which shows on the graph. It is recessed compared to the slightly elevated mid-bass but it sounds cohesive. Texture and tonality with vocals is incredible, as is clarity. And male vocals don’t sound under-done.

  • Upper mid-range – elevated compared to lower mid-range, but utilising the natural rise which lends to great cohesion between upper and lower mid-range. Clarity and air carry incredible detail, and female vocalists in particular have a touch of euphony in their presentation. For me the mid-range on the HD820 is sublime.

  • Lower treble – detailed, extended, maybe slightly on the bright and airy side, but not peaky at all, and in perfect harmony to the rest of the sonic signature. Cymbals especially are a joy to behold, with the decay from hits, or softer brush strokes (Jazz) sounding very alive, and definitely realistic. The relationship between the mid-range and lower treble is one of my favourite parts of the overall signature.

Resolution / Detail / Clarity

  • Cymbal hits and decay on cymbals have life-like presence, no early truncation on decay.

  • Excellent portrayal of both texture and tone throughout the spectrum

  • Micro details clearly presented – from the sounds of fingers sliding on strings through to singers drawing a breath. Life-like.

Sound-stage, Imaging

  • I haven’t heard anything which images quite like the HD8xx series, and definitely not in a closed back. Precise, clear and spacious.

  • Directional queues are extremely good, and portrayed outside the periphery of my head space with binaural tracks – excellent width and depth. Not quite as wide or deep as my HD800S, but easily the best sense of space on any closed headphone I’ve heard to date. I use Amber Rubarth’s binaural album Sessions from the 7th Ward, and I know from video footage how they’ve positioned the instruments ( The HD820 manages brilliant realism with Amber’s tracks, and for me that is far more important than the illusion of width that isn’t really there.

  • Completely spherically presented stage with impressive width depth and height

  • Holographic and compelling sense of immersion both with applause section of Loreena McKennit’s live recording of “Dante’s Prayer” (the HD800S has me sitting in the crowd with the applause washing around me).

  • Worth noting – I have also found the HD820 to be a very good headphone for gaming – with a clear portrayal that aids directional queues without being too clinical (still fun).


  • Tonality and timbre are fantastic for a closed back headphone.

  • Reasonably lifelike portrayal of instruments. I play acoustic guitar, and my grandmother played piano for years, so I’m very familiar with how they sound live. The HD820 (like my HD800S) manages to put me in the room with a lot of tracks. That is pretty special.

  • Excellent with both male and female vocals

  • Genre master – I enjoyed it with all genres tested – from classical, jazz and blues to electronic, grunge and pop.


  • Like the HD800S, I’m struggling to find any sonic weaknesses.


I find it oddly comical at times when people talk about having to find the right amp with any of the HD8xx series. That wonderful word “synergy”. For my part, I’ve found the HD820 sounds great with most sources, ans long as there is enough voltage to properly drive the transducers.

I tried various amplifiers (properly volume matching with an SPL meter and test tones), with the aim at seeing what level of amplification was required, and what (subjectively) I preferred with the HD820.


For a desktop solution, I tried Venture Electronic’s $800 Enterprise tube amp, and also my iFi iDSD. Both sounded fantastic with the HD820, and both really do justice to it sonically. Both are slightly warm with their presentation, but without any mushing or masking (there is still a lot of precision). I’m able to do some fast switching between the two amp stages (both using the iDSD DAC, and volume matched with an SPL meter to within 0.2dB). The real difference is that the Enterprise sounds just a little more laid back (2nd order harmonics?) than the iDSD. The Enterprise is my preference with both the HD800S and the HD820. With both the iDSD and iDSD/Enterprise combo, volume was only about quarter of the pot – so plenty of headroom.

The next test was using the Q5 and AM5 high powered amp module simulating a cheaper desktop DAC/amp option. On low gain, the HD820 only needed just over half the pot to get to my listening level, and there isplenty of headroom for even the loudest listener.

My subjective desktop rankings from the gear tested – ranked from top to bottom would look like this:

  1. iDSD + VE Enterprise + HD820

  2. iDSD + HD820

  3. Q5 + AM5 + HD820

Portable Devices

The HD820 is a pretty benign load if the player has a half decent amplification system, and one of the things I love doing is trying it with a reasonable portable source. I already knew the Q5 + AM5 worked well, so while I compared the output in a final shoot-out, I won’t go back over old ground.

First up was the FiiO X7ii – with the AM3C module – using th 4.4mm pentaconn balanced. At a volume level of 65/120 on low gain I am getting a target SPL of 70-75 db A-weighted. Interestingly the M11 (also via the 4.4mm requires almost the same volume (one click difference). The sound is incredibly well layered and dynamic, and this set-up would be perfect for taking the HD820 to another room or outside on the deck during a quiet sunny day. The main difference between the two is that the X7ii + AM3C model is a slightly more relaxed presentation, where the M11 has a bit more edge.

The final test was with the X7ii feeding the XRK-NHB (a portable amp powered by dual 9V batteries and designed to enhance 2nd order harmonics – similar to a tube amp). This combo is fantastic, and once again only using about 25-30% of the available pot. As long as a bit of extra bulk doesn’t put you off, this combo is sublime.

My subjective portable rankings from the gear tested – ranked from top to bottom would look like this:

  1. X7ii + XRK-NHB + HD820

  2. M11 or X711 + HD820

  3. iPhone XR with Q5 + AM5 + HD820

The reality though – they all sound fantastic with the HD820, and as far as pure transportability goes, all are great options for enjoying music away from the main listening station.



Very good – especially with FPS. Nice clarity, very good 3D imaging and positional awareness, and a bit of fun to boot. The bottom end of the HD820 is immersive – but it does this without masking detail of what is happening around you.


I combined the HD820 with the iDSD and Darin Fong’s OOYH and settled down to watch parts of “Inception”. I love this move both for it’s score, and also some of the dramatic and dynamic audio moments in the movie. With this set-up, the movie was very immersive, and TBH I’d prefer utilising the HD820 than using our modest Sony speaker set-up at home. Again – recommended.


For this section I only really wanted to compare the HD820 to my HD800S. I really don’t have any closed headphones which could go toe to toe with the HD820.

All of these comparisons are very subjective – and influenced by my own preference, physiology and bias. Comparison was performed with the iDSD and Enterprise. All comparisons were volume matched with a 1 kHz tone and using a proper SPL meter first.

HD820 vs HD800S

I won’t dwell too much on the physical except to say that the 30g difference in weight isn’t very noticeable, but the added clamp definitely is. The HD820 is more noticeable on the head – not in a bad way – just more acutely aware of its presence. The only other physical thing well worth noting is that my wife very much prefers the reduction in leakage of the HD820 over the HD800S.

Sonically the HD800S is a little leaner and flatter in the bass. It also has a more expansive sound scape. The mid-range and lower treble on both is surprisingly similar, and I thing this is the real magic of the DD820. Sennheiser have managed to produce a headphone sonically very similar to the HD800S but with the added isolation – but without many of the penalties we associate with a closed headphone. There really isn’t too much more to say.

  • HD820 – warmer, a little less expansive, but comparatively still quite open sounding, detailed, clear, articulate, fast. Leaks some sound but vastly less than the HD800S.

  • HD800S – a little leaner, lighter, faster with a wider stage. Leaks a lot of sound compared to the HD820.


This one is the elephant in the room for me. At an RRP of ~ USD 2300 (and 2nd hand listings around USD 1800), the HD820 is a considerable step-up from the USD 1600-1700 HD800S (especially if you shop around – they’ve been going as low as USD1200 in some cases). There is no doubting the technology, nor the sound Sennheiser has achieved.

If I was to buy again, and they were both the same price, I’d probably choose the versatility of the HD820 over the slightly superior (IMO) sonics of the HD800S. But not at USD 2300. At a similar price point to the HD800S, I’d be recommending the heck out of the HD820. At its current price, I’ll return it with regret, and secretly watch for sales in case it gets to a more affordable (an realistic) price point.


And here I am at the end of my time with the HD820, and one I’ve thoroughly enjoyed, and am sad that it is ending. Like the HD800S, the HD820 does very little (if anything) wrong, and practically everything (for my tastes) right.

From design and build through to fit and finish, the HD820 is definitely worthy of being called TOTL and IMO is one of the best dynamic circum-aural closed headphones you can buy today. Build is very good, and the added isolation has been brilliant for my own personal situation. One thing that needs stating though is that while the HD820 is technically closed, there is still some leakage and isolation is not high. It is much better than the very open HD800S though!

Like the HD800S, the HD820 retains previous strengths of imaging and sound-stage whilst not sacrificing tonality and balance wither. Overall the balance, tonality and timbre are simply sublime, and all I could personally want in a closed headphone. The HD820 is not particularly picky (IMO) regarding source or amplification. It sounds really good out of practically everything I’ve tried

The only real nit-pick I have with the HD820 is the price, and for me I’m struggling to see the overall value at $2300. That will depend on personal circumstance though.

I’d like to end by thanking Sennheiser for the chance to review the HD820, and also Matt for making it possible.

I wish I had a pair.