Sennheiser HD 820

Reference class open-back audiophile headphones

Original price was: £1,799.00.Current price is: £1,299.00.


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Sennheiser HD 820 £1,799.00 Original price was: £1,799.00.£1,299.00Current price is: £1,299.00.

A benchmark listening experience as vivid as it is uninterrupted.

The new audiophile standard

Critics claimed that closed headphones could never sound as immersive as their open-air counterparts, arguing that physics would not permit it. However, the HD 820, with its innovative glass reflector and ring radiator transducer technology, challenges this notion, offering a benchmark listening experience.

Completely closed. Outrageously open.

The HD 820 combines cutting-edge transducer capabilities with exceptional ambient noise attenuation, transcending the perceived limits of closed headphones.

Previously, the audiophile headphone experience was primarily associated with Sennheiser’s open-back design—a design that established a class of precision listening devices. This standard of sound reproduction, surpassing hi-fi systems much larger in size and cost, did not isolate listeners from their surroundings. The HD 820, with its innovative acoustical systems, offers detailed sound and a wide sound field in a closed, dynamic headphone.

Reflecting within

Producing the wide, natural sound field of an open-back headphone in a closed-back design necessitates rethinking the directional characteristics of sound waves.

Fellowship of the Ring

The 56mm ring radiator in the HD 820 is an achievement in itself. It utilizes the key benefit of a large diaphragm transducer—air displacement—while maintaining the rigidity that favorably impacts rest and response times.

In the HD 820, both outer and inner edges of the ring are secured to the drive unit, unlike a single attachment on the transducer’s outer circumference. The voice coil vibrates the diaphragm connected to the V-shaped groove near the ring’s center. The headphone’s vibration-damping chassis and inert headband insert provide complete stability, resulting in astonishing speed and accuracy across the entire frequency spectrum. The input into the HD 820 precisely reflects what is received, as each transducer is manufactured, tested, and measured to extremely tight tolerances, ensuring dependable performance. Each HD 820 also includes a frequency response plot unique to its serial number, demonstrating a commitment to helping users retrieve critical details from every corner of their music collection.


  • The new audiophile standard for closed-back headphones
  • Concave Gorilla Glass reflectors deliver impressive spatial sound reproduction
  • Ultra-ergonomic adjustable metal headband with inner damping element
  • Developed in Germany and precision-built at Sennheiser’s state-of-the-art Ireland plant
  • Frequency Response: 6 – 48,000 Hz (-10 dB)
  • 56mm Ring Radiator dynamic transducer system
  • Acoustic absorber system prevents frequency masking for unheralded detail
  • Luxuriously comfortable microfiber ear and headband padding on key contact points
  • Impedance: 300 ohms
  • Total harmonic distortion: 0.02 % (1 kHz 1 Vrms)



5 Years