Audio T Verdict
The Sennheiser HD 820 solve a problem that sounds almost contradictory: how do you create a genuinely spacious reference headphone while keeping the earcups closed? Sennheiser's answer is one of the most distinctive headphone designs around, combining its huge 56mm Ring Radiator transducers with curved Gorilla Glass reflectors and an acoustic absorber system.
The result does not pretend that a closed headphone is identical to an open one, but the HD 820 sound remarkably expansive while providing a level of privacy and passive isolation that the HD 800 S simply cannot offer. Bass has greater physical presence within the sealed enclosure, detail retrieval is exceptional and stereo positioning remains one of the strongest aspects of the design.
They are also ruthlessly revealing. At 300 ohms, good amplification is strongly recommended, and at this level the source and headphone amplifier become part of the buying decision rather than an afterthought. Partner them properly, though, and the HD 820 provide a rare combination of reference-quality listening, excellent isolation and the ability to enjoy music without sharing quite so much of it with everybody else in the room.
Closed-Back Isolation, Not Active Noise Cancellation
The HD 820 reduce outside noise through their sealed acoustic design and closely fitting earcups. They do not use electronic Active Noise Cancellation, Bluetooth or a rechargeable battery. They are completely passive wired hi-fi headphones.
Sennheiser HD 820 Closed-Back Headphones
The Sennheiser HD 820 are reference-class closed-back headphones built around a 56mm Ring Radiator dynamic transducer and an innovative acoustic reflector system designed to retain much of the spatial presentation normally associated with open headphones.
Rather than placing a conventional solid cover immediately behind each transducer, Sennheiser uses a concave Gorilla Glass panel. Sound travelling backwards from the driver is reflected by the curved glass towards an acoustic absorber, where unwanted energy can be controlled instead of repeatedly bouncing around the earcup.
The HD 820 combine this system with 300-ohm transducers, low distortion, carefully controlled mechanical damping, microfiber contact surfaces and two detachable three-metre cables for conventional 6.35mm and balanced 4.4mm headphone outputs.
- Reference-class closed-back headphones
- 56mm Ring Radiator dynamic transducers
- Concave Gorilla Glass acoustic reflectors
- Sennheiser acoustic absorber system
- Designed to reduce unwanted resonances and frequency masking
- Angled transducer presentation
- Vibration-damped chassis
- Inert headband damping element
- 6Hz to 48kHz frequency response
- 300-ohm nominal impedance
- 103dB SPL at 1V
- Less than 0.02% THD
- Wide stereo soundstage for a closed headphone
- Strong passive acoustic isolation
- Reduced sound leakage
- Handcrafted microfiber earpads
- Microfiber headband contact surface
- Adjustable metal headband
- 360g headphone weight
- Detachable symmetrical cables
- 3m 6.35mm unbalanced cable supplied
- 3m 4.4mm balanced cable supplied
- Optional XLR-4 cable available separately
- Storage box supplied
- Microfiber cleaning cloth supplied
- Developed in Germany
- Precision-built in Ireland
Closed-Back Without the Usual Closed-Back Sound
Closing the rear of a headphone driver normally creates a completely different acoustic environment from an open design.
Energy generated behind the diaphragm cannot simply escape into the room. Instead, it reflects from the interior of the enclosure and can interact with the transducer again.
If those reflections are not carefully managed they can introduce:
- Colouration
- Resonances
- A more enclosed presentation
- Reduced stereo depth
- Blurred low-level information
The HD 820 have been engineered specifically around reducing those effects.
Concave Gorilla Glass Reflectors
The transparent panels on the outside of each earcup are not there simply to show off the Ring Radiator transducers.
They are formed from concave Gorilla Glass and are an important part of the acoustic system.
Rearward sound from the transducer meets the curved glass and is redirected towards a carefully positioned absorber rather than being allowed to reflect randomly around the earcup.
Why Glass?
The rigid glass surface gives Sennheiser precise control over the direction in which the rearward acoustic energy is reflected.
The shape of the panel is therefore just as important as its material. Its job is to guide unwanted sound towards the absorber rather than simply sealing the enclosure.
The transparent appearance is visually distinctive, but the underlying reason for using the concave panel is acoustic rather than cosmetic.
Acoustic Absorber Technology
Once reflected by the glass, unwanted rearward energy is directed towards Sennheiser's absorber system.
This helps reduce resonant peaks within the earcup and the frequency-masking effect those peaks can create.
What Is Frequency Masking?
The human ear can struggle to perceive a quiet frequency when a significantly louder nearby frequency is present at the same time.
The quieter information has not disappeared from the recording, but our perception of it becomes obscured by the stronger sound.
By controlling unwanted resonance, the HD 820 allow subtle information within the music to remain easier to perceive.
The Glass Is More Than a Window
It is easy to look at the transparent HD 820 earcups and assume the glass is primarily a styling feature. In reality, the curved Gorilla Glass is part of the acoustic design, reflecting sound from the rear of each Ring Radiator towards an absorber so that unwanted energy can be controlled inside the closed enclosure.
56mm Ring Radiator Transducers
The HD 820 use the same fundamental Ring Radiator concept that established Sennheiser's HD 800 family.
At 56mm, the transducer has a very large radiating surface compared with many conventional dynamic headphones.
Simply making a diaphragm larger, however, creates additional challenges. A large conventional membrane can become increasingly difficult to keep rigid and controlled as it moves.
How the Ring Radiator Works
Instead of using a diaphragm attached only around its outer circumference, Sennheiser's design secures both the inner and outer edges of the ring-shaped membrane to the drive unit.
The voice coil excites the diaphragm through a V-shaped groove near the centre of the ring.
This allows the transducer to combine the air-moving capability of a large diaphragm with greater control over unwanted deformation.
Why a Large Driver Matters
A large radiating surface can move significant amounts of air without requiring excessive excursion.
When properly controlled, that can contribute to:
- Low distortion
- Strong low-frequency extension
- Fast transient response
- Fine dynamic resolution
- A sense of scale
- Precise spatial information
6Hz to 48kHz Frequency Response
Sennheiser's current HD 820 specification gives a frequency response extending from 6Hz to 48kHz.
The figures extend beyond the normal limits of human hearing, but the important point is not whether somebody can consciously hear 48kHz.
The wide operating bandwidth allows the transducer to reproduce the audible range without spending normal listening conditions close to its mechanical extremes.
Deep Closed-Back Bass
The HD 820 naturally present low frequencies differently from the open HD 800 S.
The sealed enclosure maintains greater acoustic pressure around the ears, giving bass notes a more physical and substantial presence.
The emphasis remains on definition rather than simply creating the maximum possible bass level.
This allows the HD 820 to reveal texture and pitch in:
- Bass guitar
- Double bass
- Kick drums
- Electronic bass
- Low piano notes
- Orchestral percussion
- Organ
- Film soundtracks
103dB SPL at 1V
Sennheiser specifies 103dB SPL at 1V.
That figure should be considered alongside the 300-ohm nominal impedance when choosing a suitable amplifier.
The HD 820 are not impossibly difficult to drive, but they are designed to reveal enough information that amplifier quality becomes extremely important.
300-Ohm Impedance
Like several of Sennheiser's established reference headphones, the HD 820 use a 300-ohm nominal impedance.
A high impedance places different demands on an amplifier from a low-impedance portable headphone. The amplifier needs to provide sufficient voltage while maintaining low distortion and good control.
A Good Headphone Amplifier Is Strongly Recommended
The HD 820 can make differences between headphone amplifiers very obvious. At this level we would recommend considering the amplifier as part of the complete system. A capable dedicated headphone amplifier, DAC/headphone amplifier or carefully designed integrated amplifier will normally allow the HD 820 to perform much closer to their potential than a basic convenience headphone socket.
Less Than 0.02% Distortion
Total harmonic distortion is specified below 0.02% at 1kHz and 100dB.
Low distortion is particularly important for a headphone intended for both serious music listening and system assessment.
Small details in the recording remain easier to identify when they are not being masked by additional harmonic information generated by the transducer itself.
A Very Wide Stereo Image
The HD 820 cannot completely remove the acoustic differences between closed and open headphones, but their soundstage is unusually spacious for a sealed design.
The Ring Radiator transducers, angled presentation and carefully controlled rear reflections help create clearly defined positions across the stereo image.
This makes it easier to follow:
- Individual performers
- Vocal placement
- Recording-room ambience
- Front-to-back depth
- Left-to-right positioning
- Small spatial cues within live recordings
Angled Driver Presentation
Sennheiser positions the transducers so that sound arrives at the ears from an angle rather than firing directly across the sides of the listener's head.
This more closely resembles the direction from which sound reaches us when listening to conventional loudspeakers positioned in front of the listening seat.
It contributes to the unusually broad spatial presentation of the HD 820.
Excellent Passive Isolation
The other half of the HD 820 story is isolation.
Unlike an open HD 800 S, the HD 820 substantially reduce interaction with the surrounding room.
This is useful when:
- Other people are in the same room
- Background conversation is present
- You are listening in a home office
- You want to concentrate on a component or recording
- You need to keep sound leakage under control
Audio T Uses Them as a Reference Tool
Our Reading team has used the HD 820 as a reference when assessing systems and even checking the results of turntable and cartridge setup.
The combination of revealing sound and strong passive isolation makes them particularly useful in a shop environment where an open headphone would allow substantially more surrounding noise into the listening experience.
You can read more in Don't You... Forget About Me! Hi-Fi We Miss When It's Not Around... from Audio T Reading.
Isolation Without Electronic Processing
There are no microphones listening to the outside world and no DSP generating an anti-noise signal.
Instead, isolation is achieved physically through the closed enclosure and earpad seal.
That means the incoming analogue signal reaches a completely passive headphone with no ANC processing imposed on it.
Handcrafted Microfiber Earpads
Sennheiser currently specifies handcrafted earpads made from high-quality microfiber fabric.
The pads form an important part of both comfort and isolation, creating the physical interface between the earcups and the listener.
On a closed headphone, maintaining that seal also affects bass performance and overall tonal consistency.
Microfiber Headband Padding
Soft microfiber is also used at key headband contact points.
The HD 820 are physically large headphones, so distributing their weight comfortably becomes particularly important during longer listening sessions.
Adjustable Metal Headband
The headband uses a metal structure for strength and accurate adjustment.
Sennheiser also incorporates an inert damping element into the headband to reduce unwanted mechanical vibration passing through the headphone structure.
Vibration-Damped Chassis
The Ring Radiator is only useful if the rest of the headphone gives it a stable platform from which to operate.
Sennheiser therefore pays close attention to mechanical resonance as well as the behaviour of air within the earcup.
The chassis and headband damping are intended to ensure that the transducer supplies the movement while the surrounding structure contributes as little unwanted vibration as practical.
360g Weight
The HD 820 weigh approximately 360g without their cable.
That is slightly heavier than the open HD 800 S but remains relatively modest considering the size of the earcups, glass acoustic reflectors and closed enclosure.
Two 3m Cables Included
The current HD 820 package contains two symmetrical detachable cables, each approximately three metres long.
One terminates in a conventional 6.35mm stereo jack and the other in a balanced 4.4mm connection.
This means the most commonly required single-ended and modern balanced connections are both covered straight from the box.
6.35mm Unbalanced Cable
The conventional cable connects directly to the full-sized headphone sockets commonly found on:
- Integrated amplifiers
- Dedicated headphone amplifiers
- DAC/headphone amplifiers
- AV receivers
- Professional audio interfaces
4.4mm Balanced Cable
The second supplied cable terminates in the increasingly common 4.4mm balanced connector.
This is particularly useful with modern high-performance headphone amplifiers and digital audio players that provide a dedicated balanced output.
Does Balanced Automatically Sound Better?
No.
The benefit depends on the design of the headphone amplifier. Some products provide greater voltage, lower crosstalk or their optimum circuit implementation through the balanced connection, while others perform equally well through their conventional output.
The quality of the amplifier is more important than choosing a socket purely because it says balanced.
Optional XLR-4 Cable
Sennheiser also offers an XLR-4 cable option for suitable balanced headphone amplifiers.
It is worth noting that this cable is now an optional accessory rather than part of Sennheiser's current standard HD 820 package.
Current Box Contents Have Changed
Older HD 820 packages included additional items, and historic specifications may mention an XLR-4 cable and USB flash drive containing the individual frequency-response measurement. Sennheiser's current package specifies the 6.35mm and 4.4mm cables, instruction manual, storage box and microfiber cloth. Frequency-response USB sticks have not been included since May 2023.
No USB Frequency-Response Stick in Current Production
Earlier HD 820 headphones were supplied with a USB flash drive containing an individual production frequency-response measurement.
Sennheiser discontinued this practice in May 2023 for the HD 820, HD 800 S and HDV 820.
Current stock should therefore not be advertised as including the USB measurement simply because older manuals or retailer specifications still mention it.
Storage Box Included
The HD 820 are supplied with a dedicated storage box.
For a headphone of this size and value, having somewhere appropriate to keep them when not in use is much more useful than simply leaving them sitting on a desk or hi-fi rack gathering dust.
Microfiber Cleaning Cloth Included
Sennheiser also supplies a microfiber cloth to help keep the external surfaces and distinctive glass panels clean.
Developed in Germany, Built in Ireland
The HD 820 are developed and engineered in Germany, while current production takes place at Sennheiser's specialist Ireland facility.
Each transducer is manufactured, tested and measured to tightly controlled tolerances before final assembly.
HD 820 or HD 800 S?
HD 820
- Closed-back
- 56mm Ring Radiator
- Concave Gorilla Glass reflectors
- Acoustic absorber system
- 300-ohm impedance
- 6Hz to 48kHz response
- 103dB SPL at 1V
- Less than 0.02% THD
- 360g
- Strong passive isolation
- Much lower sound leakage
- More physical closed-back bass
- 3m 6.35mm cable supplied
- 3m 4.4mm balanced cable supplied
HD 800 S
- Fully open-back
- 56mm Ring Radiator
- Acoustic absorber system
- 300-ohm impedance
- 4Hz to 51kHz response
- 102dB SPL at 1V
- Less than 0.02% THD
- 330g
- Virtually no isolation
- Substantial sound leakage
- Maximum sense of openness and scale
- 3m 6.35mm cable supplied
- 3m 4.4mm balanced cable supplied
Which Should You Choose?
The Sennheiser HD 800 S remain the natural choice if you have a genuinely quiet room and want the greatest possible openness and spatial scale.
The HD 820 become compelling when that environment does not exist.
They keep considerably more outside sound away from the listener and substantially reduce leakage into the room while retaining an unusually spacious presentation for a closed headphone.
This is a case where listening environment matters every bit as much as specification.
HD 820 or HD 620S?
HD 820
- Reference-class closed-back design
- 56mm Ring Radiator
- Gorilla Glass reflectors
- 300-ohm impedance
- 6Hz to 48kHz
- 103dB SPL
- Less than 0.02% THD
- 360g
- Exceptional isolation
- Very wide closed-back presentation
- 4.4mm balanced cable supplied
- Flagship closed-back model
HD 620S
- Closed-back
- 42mm driver assembly
- 38mm diaphragm
- 150-ohm impedance
- 6Hz to 30kHz
- 110dB SPL
- Less than 0.05% THD
- Angled transducers
- Wide soundstage for a closed headphone
- Much more accessible system requirement
- 1.8m 3.5mm cable supplied
- Excellent step into serious closed-back hi-fi
When Is the HD 820 Worth the Step Up?
The HD 620S are a very accomplished closed-back headphone and arguably the more sensible answer for many systems.
The HD 820 move into a different class of transducer, construction and spatial performance. Their Ring Radiator system, Gorilla Glass reflector arrangement and extremely low distortion are aimed at listeners building a reference-level headphone system rather than simply looking for a good pair of closed headphones.
HD 820 or HD 660S2?
The HD 660S2 are fully open 300-ohm headphones with a warmer, more intimate presentation and strong sub-bass extension.
The HD 820 provide considerably greater isolation, lower sound leakage and a much broader sense of spatial scale.
The decision is not simply about price. Someone who loves the close, natural presentation of the HD 660S2 may prefer that style even with a larger budget, while somebody prioritising isolation and spatial information may naturally gravitate towards the HD 820.
Sennheiser HDV 820 Partnership
Sennheiser's HDV 820 Headphone Amplifier is an obvious partnering option.
It provides both balanced and conventional headphone connections and has been developed specifically for high-performance Sennheiser headphones.
That does not mean it is the only suitable amplifier. Audio T stocks a range of headphone amplifiers and DACs, and the HD 820 are revealing enough that comparing amplification can be well worth the effort.
Audio T Has Heard the HD 820 With Chord Electronics
Our Reading team has also spent time listening to the HD 820 through the compact Chord Electronics Anni amplifier, partnered with a Qutest DAC and Bluesound source.
The combination demonstrated just how much the HD 820 can respond to high-quality desktop amplification while remaining practical in a system that occupies relatively little space.
Read Anni Are You OK? A First Look at the Chord Anni with the Sennheiser HD 820 on the Audio T blog.
Excellent for Critical Listening
The combination of high resolution and strong passive isolation can make the HD 820 particularly effective for close examination of a recording or system.
Unlike open reference headphones, less of the surrounding environment is mixed into the listening experience.
This can help when comparing:
- DACs
- Headphone amplifiers
- Sources
- Different masters
- Streaming quality
- Turntable setup
- Cartridge alignment
Excellent for Late-Night Listening
The reduction in sound leakage makes the HD 820 far easier to use late at night than a fully open reference headphone.
They are not completely silent to somebody sitting immediately beside you, but the difference compared with an HD 800 S or other open headphone is substantial.
Excellent for Shared Rooms
If the hi-fi system lives in a family room or shared office, an open headphone may simply be impractical regardless of how good it sounds.
The HD 820 allow reference-level headphone listening without forcing everybody else in the room to listen along.
Excellent for Film Listening
The wide soundstage, deep low-frequency extension and excellent isolation can also work particularly well for film soundtracks.
Dialogue remains focused, while effects and music can occupy a surprisingly broad stereo image for closed headphones.
No Batteries, Bluetooth or Firmware
The HD 820 are completely passive wired headphones.
There is no rechargeable battery to age, wireless standard to become outdated, app to maintain or firmware required before listening.
The performance is determined by the headphones themselves and the equipment feeding them.
Built for Long-Term Ownership
Sennheiser continues to provide service support and replacement parts for the HD 820.
The detachable cables and replaceable components are particularly important at this level, where the headphones should be regarded as a long-term part of a system rather than a disposable electronic accessory.
Who Are the Sennheiser HD 820 For?
- Serious home hi-fi listeners
- Listeners wanting reference-quality closed-back headphones
- People who cannot use fully open headphones
- Shared listening rooms
- Home offices
- Listeners who value strong passive isolation
- People wanting reduced sound leakage
- Listeners who value a wide stereo soundstage
- Critical listening and system assessment
- Dedicated headphone systems
- Owners of high-quality headphone amplifiers
- Balanced 4.4mm headphone systems
- Film and late-night listening
- Listeners looking for a closed alternative to the HD 800 S
Who Are They Not For?
- Listeners specifically wanting the complete openness of the HD 800 S
- Customers looking for Bluetooth headphones
- People wanting Active Noise Cancellation
- Very low-powered headphone outputs
- Customers looking for compact folding travel headphones
- Listeners wanting a built-in microphone
- People wanting a forgiving headphone that disguises poor recordings or sources
- Customers who do not intend to partner them with suitably capable amplification
Key Features
- Sennheiser HD 820
- Article number 507435
- Reference-class headphones
- Closed-back acoustic design
- Around-ear / circumaural fit
- Dynamic transducer principle
- 56mm Ring Radiator transducers
- Ring diaphragm secured at inner and outer edges
- V-shaped diaphragm drive groove
- Concave Gorilla Glass reflectors
- Acoustic absorber system
- Reduced frequency masking
- Angled driver presentation
- Vibration-damped chassis
- Inert headband damping insert
- 6Hz to 48kHz frequency response
- 300-ohm nominal impedance
- 103dB SPL at 1V
- Less than 0.02% THD
- 10.5mT magnetic field
- Wide closed-back stereo soundstage
- Strong passive acoustic isolation
- Reduced sound leakage
- Handcrafted microfiber earpads
- Microfiber headband contact surface
- Adjustable metal headband
- 360g headphone weight
- Detachable symmetrical cables
- Two 3m cables supplied
- 6.35mm unbalanced cable
- 4.4mm balanced cable
- Optional XLR-4 cable available
- Storage box supplied
- Microfiber cleaning cloth supplied
- Developed in Germany
- Precision-built in Ireland
- No Bluetooth
- No battery
- No Active Noise Cancellation
- No microphone
- No app required
- 24-month manufacturer's warranty
Frequently Asked Questions
Are the Sennheiser HD 820 still current?
Yes. The HD 820 remain part of Sennheiser's current premium wired and HD Series headphone range.
Are the HD 820 closed-back?
Yes. They are reference-class closed-back around-ear headphones.
What makes the HD 820 different from normal closed headphones?
Sennheiser combines 56mm Ring Radiator transducers with curved Gorilla Glass reflectors and an acoustic absorber system designed to control the rearward energy that would normally reflect around a closed earcup.
Why are the earcups made from glass?
The concave Gorilla Glass surfaces reflect sound from the rear of each transducer towards an absorber. The transparent appearance is distinctive, but the glass performs a genuine acoustic function.
Does the glass make the HD 820 open-back?
No. The HD 820 remain closed-back headphones. The reflector system is designed to control internal reflections while preserving as much openness and spatial information as possible.
What size drivers do the HD 820 use?
56mm Ring Radiator dynamic transducers.
What is a Ring Radiator?
It uses a ring-shaped diaphragm secured at both its inner and outer edges rather than a conventional membrane attached only around its outside circumference. The voice coil excites the diaphragm through a V-shaped groove near the centre of the ring.
What does the acoustic absorber do?
It helps control resonances and reduce frequency masking so quieter information within the recording is less likely to be obscured by stronger nearby resonant energy.
What is the frequency response?
Sennheiser's current specification is 6Hz to 48kHz.
What impedance are the HD 820?
300 ohms.
How sensitive are they?
Sennheiser specifies 103dB SPL at 1V.
What is the total harmonic distortion?
Less than 0.02% at 1kHz and 100dB.
What is the magnetic field?
10.5mT.
Do the HD 820 need a headphone amplifier?
A good headphone amplifier is strongly recommended. They are 300-ohm reference headphones and are sufficiently revealing that amplifier quality can make a substantial difference.
Can I use them with an integrated amplifier?
Yes, provided the amplifier has a capable headphone output suitable for 300-ohm headphones.
Can a phone drive the HD 820?
Some portable DAC/headphone adapters may produce sound, but the HD 820 deserve considerably more capable amplification if you want to hear their full performance.
Do the HD 820 isolate outside noise?
Yes. Their closed enclosure provides strong passive acoustic isolation compared with an open headphone.
Do they have Active Noise Cancellation?
No. Isolation is entirely passive.
Do the HD 820 leak sound?
They leak substantially less sound than open headphones such as the HD 800 S, although no passive headphone is completely silent to somebody sitting very close at high listening levels.
Are they suitable for a shared room?
Yes. This is one of their key advantages over open reference headphones.
What material are the earpads?
Sennheiser currently describes the handcrafted HD 820 earpads as high-quality microfiber fabric.
How much do the HD 820 weigh?
Approximately 360g without the cable.
What cables are included?
Current production includes a 3m 6.35mm unbalanced cable and a 3m 4.4mm balanced cable.
Is the 4.4mm balanced cable included?
Yes.
Is an XLR-4 cable included?
No. Sennheiser currently lists XLR-4 as an optional cable rather than part of the standard package.
Why do some older specifications say XLR-4 is included?
The HD 820 package has changed during the product's life. Older packages and retailer listings may therefore show accessories that are no longer included in current production.
How long are the supplied cables?
Both current cables are three metres long.
Does balanced automatically sound better?
No. The advantage depends on the headphone amplifier design and how its balanced and conventional outputs are implemented.
Is the cable detachable?
Yes. The HD 820 use detachable symmetrical cables connecting separately to each earcup.
Does the HD 820 still include a USB stick?
No. Sennheiser stopped including the individual frequency-response measurement on USB flash drives with the HD 820 in May 2023.
Why was the USB frequency-response measurement discontinued?
Sennheiser explains that headphone perception depends heavily on the listener's head, outer ear and ear canal, and that a production frequency-response measurement alone cannot predict exactly how an individual listener will hear the headphones.
Is a storage box supplied?
Yes.
Is a cleaning cloth supplied?
Yes. A microfiber cloth is included.
Where are the HD 820 made?
Current HD 820 production is developed in Germany and precision-built at Sennheiser's Ireland facility.
Are the HD 820 good for critical listening?
Yes. Their high resolution, low distortion and strong passive isolation make them particularly useful when assessing recordings or differences elsewhere in a hi-fi system.
Are they good for classical music?
They can be particularly impressive with orchestral and acoustic recordings thanks to their wide stereo image, low distortion and ability to reveal recording-space information.
Are they good for electronic music?
Yes. The closed enclosure provides strong low-frequency presence while the Ring Radiator system retains excellent texture and definition.
Are they good for films?
Yes. Their isolation, low-frequency extension and wide spatial presentation work particularly well for film and television soundtracks.
Are the HD 820 good for gaming?
The accurate stereo positioning and isolation can be excellent for gaming, although the HD 820 do not include a microphone and are primarily designed as reference hi-fi headphones.
Are they suitable for commuting?
They provide far more isolation than open headphones, but their physical size, three-metre cables and reference hi-fi focus make them much more appropriate for stationary home or studio listening than everyday portable use.
Do they have Bluetooth?
No.
Do they need charging?
No. There is no battery.
What is the difference between HD 820 and HD 800 S?
The HD 820 are closed-back and use concave Gorilla Glass reflectors to provide strong passive isolation and lower sound leakage. The HD 800 S are fully open and provide an even greater sense of openness and scale but virtually no isolation.
What is the difference between HD 820 and HD 620S?
Both are closed-back, but the HD 820 use Sennheiser's flagship 56mm Ring Radiator and Gorilla Glass reflector system with a 300-ohm impedance. The HD 620S use a 42mm driver assembly, 150-ohm impedance and provide a considerably more accessible route into spacious closed-back hi-fi listening.
What is the difference between HD 820 and HD 660S2?
The HD 660S2 are open-back 300-ohm headphones with a more intimate presentation and strong sub-bass extension. The HD 820 are closed and provide much greater isolation with a substantially wider spatial presentation.
How long is the manufacturer's warranty?
The HD 820 currently fall within Sennheiser's 24-month consumer warranty category, subject to the applicable warranty terms and proof of purchase.
What is included in the current box?
The current package contains the HD 820 headphones, 3m 6.35mm unbalanced cable, 3m 4.4mm balanced cable, instruction manual, storage box and microfiber cloth.
Related Sennheiser Products and Audio T Guides
Why Buy the Sennheiser HD 820 From Audio T?
At this level, the headphones are only one part of the system. The HD 820 are sufficiently revealing that amplifier quality, source equipment and even the choice between balanced and conventional connections can all make a meaningful difference.
Audio T can help you compare the HD 820 directly with open alternatives such as the HD 800 S and HD 660S2, or the more affordable closed HD 620S, as well as partner them with a suitable DAC or headphone amplifier.
- Friendly specialist headphone advice
- HD 820 demonstrations where available
- HD 820 and HD 800 S comparisons
- HD 820 and HD 620S comparisons
- Open and closed-back headphone guidance
- Headphone amplifier matching
- DAC and headphone amplifier advice
- 300-ohm headphone guidance
- 4.4mm balanced connection advice
- Sennheiser HDV 820 system matching
- Replacement cable and earpad guidance
- Part-exchange advice where applicable
- Ongoing after-sales support
Contact your local Audio T store if you would like to arrange a demonstration or discuss the best source and headphone amplifier to partner with the Sennheiser HD 820.