Sennheiser HD 820

The new audiophile standard

The critics said closed headphones could never sound as immersive as their open-air counterparts. They said physics would never allow it. To that we simply said, “listen”. The HD 820 combines an innovative glass reflector and ring radiator transducer technology for a benchmark listening experience.

Completely closed. Outrageously open.

The HD 820 fuses our cutting-edge transducer capabilities with exceptional ambient noise attenuation, transcending the perceived limits of closed headphones. Until now, the audiophile headphone experience could only begin with Sennheiser’s open back design—a design that paved the way for an entire class of precision listening devices. This standard of sound reproduction would go on to surpass hi-fi systems exponentially larger in size and cost with the understanding that listeners would not be isolated from their surroundings. The HD 820 sacrifices neither detail nor sound field thanks to its innovative acoustical systems in a closed, dynamic headphone.

Reflecting within

A closed back headphone able to produce the wide, natural sound field of an open one requires rethinking the directional characteristics of sound waves. While sealed headphones offer the utmost privacy, redirected energy can create resonance and distortion within the ear chamber. The reference-class experience of the HD 820 is achieved with the use of precision concave glass reflectors—one terminating each earcup. Located on the outer plane of each ring radiator transducer, this functional plate reflects energy from the rear of the driver to a specially tuned absorber system, allowing the waves to mimic the behaviour exhibited in open-air models such as the HD 800S. While also a striking visual feature, the technical execution of the glass reflector yields a sound stage never before experienced in a sealed headphone.

Fellowship of the Ring

An achievement in its own right, the 56mm ring radiator found in the HD 820 leverages the key benefit of a large diaphragm transducer—air displacement—without losing the rigidity that favorably impacts rest and response times. Instead of a single attachment on the outer circumference of the transducer, both outer and inner edges of the 'ring' are secured to the drive unit. The voice coil vibrates the diaphragm, connected to the V-shaped groove found near the center of the ring. The headphone’s vibration-damping chassis and inert headband insert provide complete stability, resulting in astonishing speed and accuracy throughout the entire frequency spectrum. What you put into the HD 820 is precisely what you will get out of it, too. Each transducer is manufactured, tested, and measured to an extremely tight tolerance to ensure the most dependable performance out of the box. Each HD 820 also includes the frequency response plot unique to that set’s serial number, sparing no resource to help you retrieve the most critical details from every corner of your music collection.