About the Sennheiser HD 820 (factory-recertified)
Factory-recertified and packed with care
The HD 820 headphones perform their best when driven by a powerful headphone amp like the Sennheiser HDV 820.
Factory-recertified and packed with care
For over a decade, Sennheiser's flagship "HD 800" series headphones have been well-loved by Crutchfield customers and audiophiles everywhere. We're offering a factory-recertified version of the sealed-back HD 820 S headphones — complete with the concave Gorilla Glass earcups — at a discount. Sennheiser is so confident in their performance, that they're including the full two-year warranty.
Sennheiser's top-of-the-line sealed headphones
When I found out Sennheiser was set to debut their new HD 820 headphones at the 2018 CES, I immediately sent an email to our video team. Our crew was already on the scene in Vegas, so I had to get their first-hand impression of these special 'phones. This is the first sealed-back model in Sennheiser's stellar HD 800 series, and the company has gone all out. The earcups are sealed with concave, heavy-duty glass covers that show off the drivers and help absorb unwanted vibrations.
The result? Transparent, spacious sound like you'd expect from an open-back headphone, but with the insulated listening experience of a closed-back design. You can check out a video of my buddy JR's full reaction in the photo carousel above. He told me he was super-impressed with the musical detail he could pick out — especially with all the hustle and bustle of CES around him.
Excerpt from my Q&A with Sennheiser's chief headphone designer Axel Grell
Jeff Miller: How and why did you land on Gorilla Glass for the HD 820s?
Axel Grell: We wanted to make a closed headphone that sounded as open as possible. So initially, we just used the HD 800 S and put a [flat, plastic] cover around it. That didn't work as well as I thought it would. So we said, “OK, the back is not good when it's flat — it needs to be concave.”
And the plastic was not stiff enough, so there were resonances. It vibrated at certain frequencies. We were looking for a stiffer material that was also lightweight.
Gorilla Glass is VERY stiff, lightweight, and it's transparent. I want to show off those transducers!
Several ways to connect
When these headphones are released later this year, they will be one of the first to use a 4.4mm balanced headphone plug. This is the new industry standard connection for balanced headphone operation, and it promises to cut down on signal noise and distortion. At CES, Sennheiser powered these 'phones with the Sennheiser HDV 820 headphone amp via this connection.
These two "820" devices — headphone and amp — were designed together in Sennheiser's German headquarters, so they pair up perfectly. Sennheiser includes another cable with an unbalanced 1/4" headphone plug. There's even a miniplug adapter included — although I wouldn't recommend trying to drive this thoroughbred with your smartphone!
Product highlights:
- inspected and factory-recertified
- assembled at Sennheiser's headquarters in Germany
- over-the-ear, closed-back design for spacious sound with tight, solid bass
- durable, see-through Gorilla® Glass covers help keep sound from escaping
- concave design absorbs vibration for low distortion
- up to 25dB noise attenuation
- specially tuned for symmetrical (balanced) operation with the Sennheiser HDV 820 headphone amp
- a high-performance headphone amp will properly power these headphones for optimum sound
High-definition Dynamic Drivers:
- large 56mm drivers produce natural, lifelike sound
- spread-out soundstage with precise musical detail
- ring radiator transducers smooth out airflow for better dynamics
- acoustic absorber technology to reduce harsh frequency extremes for smoother highs
- drivers direct sound waves to the ear at a 45° angle for a more natural listening experience
General Info and Specs:
- metal headband with layers of material to dampen vibrations
- matte black finish
- thick, handcrafted ear pads with soft microfiber fabric
- two oxygen-free cables:
- shielded cable with unbalanced 1/4" stereo plug
- specially tuned cable with balanced 4.4mm headphone plug (for compatible headphone amps)
- wooden storage case
- frequency response: 6-48,000 Hz (-10 dB)
- impedance: 300 ohms
- total harmonic distortion: less than .02% at 1Khz/1Vrms
- warranty: 2 years
- Our 60-day money-back guarantee
- MFR # HD820 REFURB
What's in the box:
Sennheiser HD 820 (factory-recertified) owner's manual
- Factory recertified over-ear headphones
- 11.33' Unbalanced audio cable (1/4" plug)
- 11.33" Balanced audio cable (4.4mm Pentacomm plug)
- Cleaning cloth
- Wooden storage box
- USB drive with manual and frequency response curve)
- Instructions
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More details on the Sennheiser HD 820 (factory-recertified)
Features & specs
| General | ||
|---|---|---|
| Fit Style | Over-the-ear | |
| Earcup Type | Closed | |
| Earcup Width x Height | 4.328" x 4.86" | |
| Noise-canceling | No | |
| Bluetooth | No | |
| Bluetooth Version | --- | |
| Single-earbud Operation | --- | |
| Mic For Taking Calls | No | |
| Voice Assistant Access | ||
| Amazon Alexa | No | |
| Google Assistant | No | |
| Siri | No | |
| Connectors | ||
| 3.5mm | No | |
| 1/4" | Yes | |
| Lightning | No | |
| 4.4mm balanced | Yes | |
| XLR4 balanced | No | |
| 2.5mm | No | |
| Other | None | |
| Specs | ||
| Frequency Response | 12-43.8k Hz | |
| Sensitivity | Not Given | |
| Impedance | 300 Ohms | |
| Weight | 18.1 ounces | |
| Cord Length | 136" + 136 | |
| Parts Warranty | 2 Years | |
| Labor Warranty | 2 Years | |
Product Research
Features
Overview: The factory-recertified Sennheiser HD 820 is the new benchmark for closed-back wired headphones. The German-made headphones come with two 3 meter cables, including a balanced cable for use with headphone amplifiers. The headphones and cables can be stored in the elegant, padded wooden box.
Closed Design: The HD 820 circum-aural (over-the-ear) headphones feature a closed design to isolate ambient noise, but still deliver a wide open sound field. With the help of the soft, hand-crafted microfiber ear pads, the headphones realize an attenuation of up to 25dB of outside noise, allowing you to listen to your music without distraction.
Transducers: The HD 820 utilizes large 56mm (2.2") ring radiator transducers, some of the largest available in a closed-back headphone. The drivers ensure ultra-low bass reproduction, as well as clear mids and highs.
Acoustic Diffraction Housing: The Sennheiser HD 820s feature a patent-pending acoustic diffraction housing to deliver a spatial and airy sound reproduction, as well as isolate external noise and sound leaking from the inside. The convex Gorilla Glass panes reflect the sound waves from the rear of the transducers into an absorber chamber to dampen and eliminate internal reflections.
Headphone Cables: The HD 820 comes with two interchangeable headphone cables, including one with balanced connections. The silver-clad OFC cables split a short distance from the headphones, and plug into each ear cup with a special, high precision ODU circular connector. The unbalanced cable is terminated with a standard, heavy-duty 1/4" plug. The balanced cable has the 4.4mm Pentaconn connector used in newer DACs and headphone amps. Both cables feature a nylon outer covering that quiets contact noise from the cable.
Storage Box: The HD 820 has a sturdy, hinged wooden box with cut-out foam padding for storage of your headphones and cables.
Specifications:
- Frequency Response: 12-43,800 Hz (-3dB); 6-48,000 Hz (-10dB)
- Nominal Impedance: 300Ω
- Max. Sound Pressure Level: 103 dB (1 kHz, 1 Vrms)
- Long-term Input Power: max 500 mW
- THD (1kHz / 1V): ±0.02%
- Ear Cup Dimensions: Width 4.328", Height 4.86", Depth 2.327"
- Weight: 13.4 ounces (w/o cable), 18.1 ounces (with 1/4" cable)
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