A new type of transducer and ear cup design are two of the key features of Sennheiser's new top-of-the-line HD800 headphones being introduced at the Winter NAMM 2009. This Audiophile model, which is sure to remind high-end enthusiasts of the company's Orpheus headphones, features a 56mm sound transducer 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 HD800. This annular design solves the problems relating to the dynamic transducer principle.
"The more transducer surface area is caused to vibrate, the purer the headphone sound becomes at low frequencies," said 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."
To ensure that the acoustics of the transducers are not impaired by any partial vibrations, the transducer is mounted in high-precision gauze made of stainless steel. The ear cups are made of high-quality plastic with quality attenuation characteristics. Further, there is no covering at all for the ear cups, and less material means that there is less opportunity for partial vibrations to occur. For the same reason, a special headband was developed for the HD800 that uses a multilayer design that attenuates vibrations, eliminating any dips in sound pressure level at low frequencies. To guarantee an optimum fit on the head, the circumaural ear cups are suspended on one side only.