A novel type of transducer and an innovative ear cup design are two of the key design features of Sennheiser’s new high-end HD 800 headphones. According to Sennheiser, this audiophile model offers brilliant sound imaging and impressive spatiality through the use of a 56mm sound transducer – currently the largest to be found in any dynamic headphones – and an ear cup design that directs sound waves to the ear at a slight angle.
The vibrating part of the diaphragm is not a circular surface area but a ring, which is able to set the entire air volume over the transducer into motion, generating the full-bodied sound of the HD 800. This annular design, patented by Sennheiser, solves the problems relating to the dynamic transducer principle for the first time. “The more transducer surface area is caused to vibrate, the purer the headphone sound becomes at low frequencies,” explains Axel Grell, acoustics developer at Sennheiser. “However, transducers with a large surface area have the disadvantage that, at high frequencies, undesired resonances known as eigenforms occur at the diaphragm. This results in distortions in sound reproduction that even high-quality Duofol laminations are not able to completely eliminate.
The ring design minimizes the distortion of the sound image, even with a transducer as large as 56mm.” The result is impressive: with total harmonic distortion of less than 0.02 percent (at 1kHz and 100dB SPL) and an outstanding frequency response of 6 to 51,000Hz, the HD 800 has brilliant trebles, precise bass reproduction and a much clearer sound image. Special attention has also been paid to the design of the ear cups. “We perceive acoustic signals to be natural when we experience them with a spatial extension,” observes Grell. “Today, most music is made to be reproduced by two loudspeakers, which form an equal-sided triangle together with the listener. This results in a sound field close to the ears that is at a slight angle to the head. When the sound field reaches the ears, the sound is reflected into the ear canal and to the eardrum by the structures of the external ear with slight time differences. It is precisely these differences that are a key factor in spatial hearing and in the localization of the sound event outside the head. With its large, inclined transducers, the HD 800 generates a sound field that corresponds to the listening experience with loudspeakers, but far exceeds loudspeakers in the purity of the sound reproduction.”
Select materials and a top-quality black/silver finish give the headphones a look of exclusive elegance. To ensure that the acoustics of the transducers are not impaired by any partial vibrations, the transducer is mounted in exclusive high-precision gauze made of stainless steel. The ear cups are made of high-quality plastic with particularly good attenuation characteristics. Further, there is no covering at all for the ear cups, as less material means that there is less opportunity for partial vibrations to occur. For the same reason, a special headband was developed for the HD 800 that utilizes a patented multi-layer design consisting of metal and high-quality plastic attenuates headband vibrations, thus effectively eliminating any dips in sound pressure level at low frequencies.
Specific cables have also been developed for the HD 800 headphones. The four-strand high-performance wires made of silver-plated, low-oxygen copper are specially shielded against electromagnetic disturbance. The two high-precision plugs and the 1/4-inch (6.3mm) jack plug are gold-plated for optimum contact. To guarantee an optimum fit on the head, the ear cups are suspended on one side only. High-quality plastic material developed for the aviation and aerospace industries ensure maximum stability. The circumaural ear cups fit comfortably around the ears without aggressive lateral pressure for hours of music enjoyment. The material used for the ear pads is Japanese Alcantara, which is particularly friendly to the skin and easy to clean.