Sennheiser took its technology to a whole new dimension in 1991 with the introduction of the Orpheus high-end headphones. “We had spent a great deal of time researching electrostatic headphones and became proficient in the technology. And then Sony made the first move and presented its rosewood classic with all the frills. The Orpheus was our comeback,” Jörg Sennheiser recalls. “A limited-edition pair of headphones for DEM 20,000.”
Manfred Hibbing was actually retired when project manager Axel Grell approached him 20 years later. “Manfred, we have to do something.” Of course, it’s great to be known for producing the best pair of headphones in the world, but Sennheiser wanted more: The Orpheus should have a successor, even better than the original. But who was still knowledgeable about this type of technology? Manfred was the obvious choice because he had previously worked on the Orpheus. Fortunately, Manfred still had a consultancy contract with the company and was available to help.
“I was the wild card. I was not working on a specific project so I had the choice of what I wanted to work on,” he smiles. “Of course I was interested. What a high note to end my career on!”
Manfred Hibbing’s former field of expertise was condenser microphones. In the 1980s, he developed the symmetrical transducer using RF technology. This led to a series of MKH microphones that were suitable for studio use because they were low-noise and low-distortion: The MKH 40 was the first in the series. “They all had the same neutral frequency response and the same sensitivity. They set new standards in the industry.” Manfred had always developed transducers and circuits for his microphones, so he always had the interface between the two components well under control.
“A parallel can also be drawn between the MKHs and the successor of the Orpheus, the HE 1,” says Manfred. “Symmetrical transducers and electronics, only this time for headphones.” He was involved in the development of the transducers and the electronics for the earpiece and the amplifier. “I grew up with tube technology.” The HE 1, however, was in a class of its own. What initially started out as a successor model naturally developed more and more momentum. “The counter electrodes for the transducer were a problem. They have to be extremely dimensionally stable, which makes them expensive.” It took two years to find the right material before finally discovering a ceramic mass that is usually used for dental crowns. “Unlike Orpheus, the HE 1 is not a purely passive listening device. We fitted high-voltage electronics in the earpiece, which in turn made special housing parts necessary to dissipate the heat generated.”
The sculptured shape of the amplifier unit and the moving features cannot fail to catch the eye. “The mechanical designers grumbled a lot because more and more had to be accommodated in the marble housing,” recalls Manfred. “Animating the amplifier was also a tricky task for the software developers. And because of the exposed tubes, electromagnetic compatibility was another issue that arose toward the end of the project. But, once again, the experienced team rose to the challenge.”
“I put my heart and soul into the project,” concludes Manfred. And in 2017, he retired for the second time. “Now I really think I deserve to put my feet up!”