Critics claim that closed-back headphones cannot even remotely compete with the sound quality of open-back systems. They argue that the design simply doesn't allow for it. What is our take on this? See for yourself! The HD 820 was developed in Germany and is characterized by the combination of an innovative glass reflector with ring radiator transducer technology. The result is an uncompromisingly vivid sound experience that sets new standards.

Closed-back system, without compromise

The HD 820 combines the renowned top-tier technology of our transducer with exceptionally high ambient noise attenuation, far exceeding all expectations for closed-back headphones.
Until now, Sennheiser has relied on the open-back headphone concept for maximum sound performance. This concept, consistently applied in design, paved the way for an entire series of high-quality, precision-engineered headphones. The standard developed here in terms of sound reproduction was even able to outperform far larger and more expensive hi-fi systems while offering the advantage of portability. The HD 820 equally combines attention to detail with a focus on unique sound. The result is the consistent implementation of an innovative acoustic system in a closed-back, dynamic headphone.

Signal transmission in a closed-back system

A closed-back headphone capable of reproducing the broad, natural sound spectrum of an open-back headphone requires rethinking the directional characteristics of sound waves.
While closed-back systems ensure the best possible intimate sound experience, they conversely imply the risk of resonances and distortion in the ear canal. In its class, the HD 820 does not need to shy away from comparison with its competitors, as it impresses with the use of precisely selected concave glass reflectors to avoid resonances in both ear cups. The unique glass covers are positioned on the outer ring of the ring radiator transducer. The concave glass, a visually striking feature, reflects the sound waves from the rear of the transducer onto an absorber. As a result, these sound waves and resonances are reduced to an absolute minimum for the first time in closed-back headphones, similar to the open-back headphones of the HD 800 S series.

The decisive effect of the ring

The 56-mm ring radiator of the HD 820 utilizes the significant advantage of a larger transducer – airflow – without neglecting the required degree of resistance with its decisive effects on settling and response times.
Instead of being attached only at the outer edge of the transducer, both the outer and inner edges of the "ring" are secured to the driver unit. The voice coil vibrates the diaphragm, which is inserted into a V-shaped groove near the center of the ring. The headphone chassis follows a damping concept to minimize vibrations. Additionally, the non-slip headband ensures a secure fit. The result is an unhindered and incredibly fast as well as precise signal transmission across the entire frequency spectrum. What matters in the end are the components integrated into the HD 820. Each individual transducer is handmade and tested and checked until it meets the lowest possible manufacturing tolerances. Only devices with maximum reliable performance leave our factory. Every HD 820 receives an individual frequency curve and corresponding serial number based on its proven bandwidth. Thus, you are perfectly equipped to put your entire music collection and individual favorites to the test.

The new standard for sound connoisseurs and lovers of closed-back systems

Dynamic transducer technology with a 56-mm ring radiator

Concave Gorilla glass reflectors deliver an impressive spatial sound reproduction

An acoustic absorber system prevents the masking of certain frequencies and guarantees maximum detail in reproduction

An ergonomic, adjustable, and padded metal headband ensures maximum comfort

At the most important contact points, the ear cups and headband are padded with pleasantly soft microfiber material, tailored to the anatomy of the head

All elements were developed in Germany and manufactured with precision at our Sennheiser production facility in Ireland.

Impedance: 300 ohms

Frequency response: 6 – 48,000 Hz (-10 dB)

Total harmonic distortion (THD): 0.02% (1 kHz / 1 Vrms)

Consistently well-thought-out technology

The stereo reproduction with an intensified, almost magical sound spectrum is the result of an elaborate technological development concept for the HD 820.
The sound angle of the driver, combined with the response behavior of the ring radiator transducer, allows for the precise reproduction of voice and instruments in a composition. You are in the middle of the action and can simultaneously escape reality. The balance between reality and the world of sound allows you to focus fully on a unique sound experience while listening to your favorite recordings. The ear padding is extremely comfortable, and the shape, perfectly adapted to the anatomy of the ear, ensures a tight fit that offers exceptional comfort even during long listening sessions. There are moments when accurate listening is essential. Especially when the situation calls for it, but also when you simply want to listen to music intensely, the HD 820 is the headphone of choice, eliminating disturbing outside noise without letting any sound elements escape to the outside.

With the HD 820, excellent comfort is guaranteed even during extended music enjoyment, and it offers a sound experience that is both luxurious and immersive.
Every single contact point of the headphone adapts to the anatomy of the head thanks to its padding. Special synthetic fibers ensure low weight and avoid an uncomfortable feeling of pressure. Each ear cup can be moved horizontally and vertically. When you put on the HD 820, it adapts perfectly to the anatomy of your head. The result is an unsurpassed listening experience that fully meets all the expectations of a sound enthusiast.

Included with our HD 820 is a versatile set of essential cables, matched to the impedance of the output device and with extremely low structure-borne noise.
The 6.3 mm plug is the standard connection for devices such as headphone amplifiers, DACs, and A/V receivers. The balanced 4.4 mm connector provides access to the new generation of balanced output devices such as headphone amplifiers, digital audio players, etc. This is where the true value of the accurate and robust connection becomes apparent. A balanced XLR-4 cable is available separately and offers further connection options to a wide range of audio output devices. Each cable is 3 m long, allowing sufficient freedom of movement even if the output device is on your shelf or desk while you get comfortable in an armchair.

High-end audiophile headphones

Closed-back system

Dynamic transducer technology with a 56-mm ring radiator

German craftsmanship

Detachable cable

Speaker frequency response
6 Hz - 48,000 Hz

Speaker sensitivity
103 dB (1 V)

Impedance
300 Ω

THD, total harmonic distortion
< 0.02% (1 kHz, 100 dB)

Cable length
3 m

Adapter
XLR-4, balanced, 4-pin stereo jack plug: 6.35 mm, unbalanced, 3-pin 4.4 mm, balanced, 5-pin

Transducer principle
Dynamic, open

Weight
360 g

Ear coupling
Circumaural

Magnetic field
10.5 mT

Article number (SKU)
507435

Herstellerangaben:

Sonova Consumer Hearing GmbH
At Laboratory 1
30900 , Wedemark
Germany
product_safety@sennheiser-hearing.com