Sennheiser HD820 Review

Sennheiser HD820 Review

28 February 2022 0 By Petros Laskis

Almost perfect

Pros: + Fun and enjoyable
+ Full and well extended bass
+ Mostly natural timbre
+ Smooth treble response much improved over the rest of the HD8 family
+ Best soundstage on a closed back headphone
+ Huge and holographic
+ Phenomenal positioning accuracy
+ Resolving and detailed but not analytical
+ Great looks
+ Excellent build quality
+ Lightweight and comfortable
+ Two cables of good quality
+ Handmade in Ireland

Cons: – Inconsistent bass response
– Bass can become hollow and boomy
– Mid – bass masking
– Fragile glass needs careful handling
– 4.4mm cable too long for portable use
– A carrying case is missing
– Not suitable for outdoor use
– Low clamping force may result into poor sealing
– Average noise isolation

This review was made possible thanks to the Sennheiser HD820 tour that was organized by the brand for Head-Fi.
My sincerest thanks for letting me participate.


The HD820 is Sennheiser’s closed – back flagship headphone building upon the success of the HD800S.
They share the same famous 56mm Ring Radiator dynamic transducer system and then incorporate various novel innovations to overcome the laws of physics in order to provide open back performance from a closed back headphone.
The most notable ones are the Concave Gorilla Glass reflectors, that deliver impressive spatial sound reproduction and the acoustic absorber system that prevents frequency masking for unheralded detail.
The HD820 is Axel Grell’s latest creation before he left Sennheiser to found his own headphone brand.


All technical specifications are available at the Sennheiser website.

Build quality and aesthetics

The HD820 is one of the best built headphones in the market, hand – made in Sennheiser’s Ireland facilities with carefully selected materials and excellent craftsmanship.
Most of the parts are made from high quality plastic and fit together with great precision.
The adjustable headband is reinforced with a metal band and has an inner damping element with a microfiber padding for extra comfort.
The newly designed earpads are hybrid, a combination of synthetic leather at the outside with microfiber on the interior.
Aesthetics are subjective, so you might feel different but I love the industrial and futuristic looks of the series even more in the HD820 with the concave gorilla glass outer parts that offer visibility of the internal driver.

Fit and isolation

The HD820 weighs only 360g and has a medium clamping force, just as needed for securing them at your head.
Due to the low pressure there is a chance that the ear cups may not seal as perfectly as it is needed for achieving the best isolation and bass response.
Sealing for my head and face shape was perfect but I can see some people with smaller heads and leaner faces having some trouble in finding the perfect fit.
Bending the headband carefully might solve the problem.
The ear pads are -D- shaped, the same as in the HD800S, so they can easily accommodate larger ears.
One positive difference is that they are slightly thicker so they feel even more comfortable and the ear cannot touch the inner mesh.
My wearing experience with the HD820 was that of great comfort, no pressure points, the headband felt well rested and I was able to use them for more than a couple of hours without any kind of annoyance minus some heat and sweat issues, something regular for all closed back headphones.
Sound isolation was perfect during use in the noisy household environment but not sufficient for blocking louder sounds.
But then I don’t see many people using them while traveling or commuting.


Cable and accessories

The HD820 package includes a sturdy storage case, a microfiber cloth, instruction manual, two cables, and a USB flash drive.
That drive contains a copy of the manual in PDF form and a diffuse-field frequency response curve for your actual pair of headphones.
The two, 3m long, detachable cables feature the lemo connectors and are terminated with 6.35mm and 4.4mm plugs respectively.
The cables are of good quality, they have a cotton sheath outer reinforcement, they are not microphonic but they do have the tendency to become tangled.
The storage case is bulky and pretty useless, it would have been much better if a nice carrying case was included instead of it.

Associated equipment

The HD820 is a $2400 pair of headphones so I guess that most people who can afford them already own a couple of high quality pieces of audio gear.
High Z Sennheiser headphones are synonymous with OTL headphone amplifiers so it would be a serious omission not to test them with the Feliks Audio Euforia.
Then for solid state duties I engaged the class A beast, the Flux Labs FCN-10, one of the best “all in one” pieces of headphone equipment.
With a sensitivity of 103dB, the HD820 is not as hard to drive as you would imagine and they can be used with high quality portable devices.
Like the exquisite FiiO M17 which proved more than sufficient for driving the HD820 with excellent control, spare headroom and high quality sound.
The stationary sources included the Lab 12 dac1 reference NOS DAC, the Audiolab 8300CDQ and the Mhdt Audio Toucan.


Listening impressions

Although I was the second person to receive the review sample nonetheless I left the headphones playing some music for about 100 hours.

The Sennheiser HD820 is another example of a headphone where the frequency response measurements don’t exactly align with the actual listening experience.
I guess that most of you have already seen the frequency response graph with the weird peaks and dips that may suggest that the HD820 is going to sound strange and out of tune.
Well, this is quite far from the truth since the sound is pretty even, with deep bass response, slightly forward mids, present treble and satisfying timbre consistency.
Let’s start with the timbre which is mostly natural and not too artificial or metallic sounding, instruments and voices are heard quite realistic and balanced.
Mids are more intense and forward but not in an annoying manner that would lead into a heavy mid – centric presentation.
Although this is not a strictly reference tuning, the end result is very emotional and musical, mids do get a great share of the show but they are not overbearing, nor are shouting or piercing.
Electric guitars, blazing horns and solo singers sound pleasing and engaging with great presence, good attack and fine articulation.
I enjoyed rock songs and baroque arias alike.
The mids are full bodied, with roundly shaped edges and great depth of expression while they are counterweighted by the sparkling treble which is present and luminous as to add the necessary energy and contrast to the mix.
Speaking of treble, the HD820 is the most smooth sounding of the whole HD8– series, including the HD8XX.
Of course DNA is still the same, slightly bright, unforgiving, detailed and very resolving but this time there are no alarming peaks or a treble plateau to cause listener fatigue and any kind of ear piercing harshness.
Timbre is much improved and more natural when compared to the HD800S.
Instruments sound closer to reality, decaying is relaxed, percussion instruments are heard more splashy and the overall body weight is increased.
Nonetheless there are still some traces of artificiality and the sound is a bit leaner and skinnier when compared with other headphones.


The bass under the microscope

The bass is tastefully elevated above the neutral reference point with great sub – bass extension that has good rumble and satisfying quantity to cater for modern electronic music.
This is the most bassy headphone of the series, full bodied and fun, yet fast, clear and controlled, a great performer minus a few quirks.
There is a mild mid – bass emphasis that makes the overall presentation a mixed bag.
The hump is not too severe as to annoyingly let the bass bleed into the mids or overshadow the treble, two parts of the region that already get their own share of boost to counteract to this gain and retain their space and freedom of expression.
The problem is focused on the bass line itself which gets self – masked and sometimes cannot be expressed with the desired clarity and layering.
With less demanding material where we have a simpler bass line the problem is not that pronounced and the bass expression ranges from very good to excellent.
As an example the “Sultans of swing” sounded fun and enjoyable, electronic music was a pleasure to listen and in string quartets, the solo cello was heard slightly colored but still in tune, tight, layered and contrasted to the viola.


Moving into more complex and demanding material is a different story though.
In large symphonic works, with heavily populated bass lines, the headphone is not up to the task as someone would expect.
There is a great inconsistency to the bass reproduction which ranges from clear, fast, tight and well layered to boomy, muddy and hollow according to the type and number of instruments that are playing simultaneously.
As an example you can clearly hear the solo bassoon or solo cello but after a while they get lost under the massive orchestral tutti when groups of lower bass instruments are engaged simultaneously.
Masking effect can become quite pronounced and there are also times when you can hear an intense cup reverb and echo.
The dynamic behavior is mostly good with contrast and muscle but sometimes the sound becomes hollow and uncontrollable like listening to the droning effect of speakers placed in an undamped room.
Stavinsky’s ballet suites are quite telling of the above mentioned issues where you can hear the inconsistency of the bass response from track to track but at the same time it can also highlight the best virtues of the HD820 like the immaculate soundstaging.


Soundstage master

Soundstage is almost on the same level with the HD800S and truly remarkable for a closed back headphone, it trumps a lot of open back headphones.
Soundstage is extended, airy, wide and spacious with one of the most accurate positioning I have ever heard.
The soundscape arrangement stays always natural and the headphone is highly adaptable to the size of the ensemble never sounding artificially diffused.
The HD820 is doing an excellent job in communicating the ambience of the recording venue while the presentation is large scale and grandiose with great layering and expanded holography.

Vs the Meze Audio Liric

Non audio comparison

In the non sound related stuff, the Liric is of better build quality, more premium materials are used and it radiates more luxury.
The Liric is also more portable despite not being foldable but on the other hand the HD820 has more roomy earpads and less weight.
In actual use both feel very comfortable and are well designed for long listening sessions without causing any discomfort.
The Liric offers a slightly more stable fit and it isolates better from external noises.
The Liric comes with an excellent carrying case which is more useful than the large storage case of the HD820.
There are two detachable cables included with the Liric, a 1.5m soft TPE cable with 3.5mm jack and a 3m with 3.5mm jack and while the HD820 cables are of better quality, the Liric cables are more easy to replace thanks to the generic 3.5mm connection plug.


Audio comparison

Sound-wise the most notable differences are related to the bass response.
The HD820 has deeper sub – bass extension and can move more air but the bass on the Liric has a considerably more reference and natural tuning up to the lower mids.
There is no mid – bass emphasis and the presentation is way more technical than the HD820.
Bass is faster, cleaner, more controlled and tight, with better layering and can resolve much better, even during the most populated passages without the slightest hint of masking.
The Liric Pressure Equalization System is working wonders, there is no pressure build up, no cup reverb or echo and the bass never sounds boomy, hollow or artificial.
Thus said, the HD820 bass is heard more visceral and full bodied with slightly better dynamics.

Unexpectedly so, the Liric sounds more sterile when it comes to the mids, with a leaner and slightly brighter character.
The sound is more clear and clean on the Liric but vocals are more shouting and leaner than in the HD820 which in contrast is more lush, pleasing and musical.

Upper treble is a touch more hot and artificial sounding on the HD820 than the Liric which has a somewhat better timbre consistency while they both resolve and detail like champs without being analytical.

The HD820 triumphs in the soundstaging abilities by a fair margin, the Liric can’t touch the overall openness and sense of space nor present the sound with the same grandeur.
Thus said, the Liric has equally amazing positioning accuracy.

Both headphones deserve their flagship status as they offer truly exceptional sound quality with two different flavors to choose your favorite.


In the end

The Sennheiser HD820 should always be judged while keeping in mind that it is a closed back headphone with all the shortcomings that apply to this principle of design.
It is only under this perspective that becomes clearly visible why it is one of the best closed back flagship headphones you can buy.
And rightfully so because of the top tier sound performance and the excellent job done by the Sennheiser engineers to successfully address most of the associated shortcomings and give it a strong technical background.
It is not perfect but only when compared to some open back flagships and then again it is almost there.

Test playlist

Copyright – Laskis Petros 2022