Development of High-Resolution Recording Microphones
Sony Taiyo Corporation is a special subsidiary company for the disabled people and is Sony's main
Japanese factory for manufacturing microphones.
For the first time in 26 years, Sony Taiyo has developed a new condenser microphone capable of
recording Hi-Res sound sources.
We interviewed the key members of the project team in creating the new product from the initial design all
the way through to production.
Up to now, Sony Taiyo has been involved in manufacturing professional microphones and headphones for recording music, where high precision is required. As a special subsidiary company where around 70% of employees are disabled, Sony Taiyo has put into practice the corporate philosophy espoused by Sony founder Ibuka Masaru, who said he would like to see "workplaces where employees with disabilities are not afforded special privileges, yet can thrive and make products that exceed those made by able-bodied individuals." Moreover, some 27 years ago, our former president talked about his dream to see products that were "Made in Sony Taiyo," words with which many employees sympathized. Although we continued to embrace that dream, there were few opportunities for us to develop, design and commercialize our own products from scratch because we are basically a manufacturing plant. That said, ever since Sony manufactured the C-37A professional condenser microphone, the first Japanese-made microphone of its kind, some 60 years ago, Sony Taiyo has inherited the technology and know-how that Sony has accumulated in the process of manufacturing high-precision audio products, and devised many methods for achieving superior sound quality. While making the most of these assets, we came up with a plan to try to develop the world's most sensitive microphone unit as a new challenge for ourselves. This is where our designer Mr. Isomura started to play a central role in developing a high sensitivity microphone unit.
Isomura: The starting point for the development was to combine the professional microphone technology Sony had accumulated so far with the one that Sony Taiyo had developed on an experimental basis. Through a process of repeated trial and error, the members of our design team succeeded in producing an experimental microphone unit (component) that could record without attenuating up to the 50 kHz bandwidth. It can cover Hi-Resolution audio bandwidths that current professional microphones have so far been unable to pick up. Although it is a very interesting component, there was very little potential for commercializing the unit on its own. For this reason, we showed it at a Sony Group technical exchange meeting with a view to publicizing the technology widely throughout Sony. The potential of this technology caught the eye of Mr. Konno from Sony Video & Sound Products (SVS), which is in charge of Sony's audio business.
Konno: I was in charge of the Hi-Res promotion operations at SVS at the time and was engaged in promoting Hi-Res sound sources while working with music labels. As I focused on asking people for remastered sound sources, I also sought newly recorded original sound sources, which awoke my interest in the characteristics of microphones used for creating music, which of course is essential to capturing sound. Then, I heard the story of an experimental microphone unit that Sony Taiyo had developed. Since I believed that there were still few if any microphones capable of recording bandwidths up to 50kHz in existence, I was very intrigued by this. Thinking about the possibilities of using it for recording Hi-Res sound sources, I began to wonder if a microphone employing this unit could be commercialized.
Morisaki: Mr. Konno's discovery of the potential of our microphone unit at the technical exchange meeting was a major event that brought us closer to realizing our dream of "Made in Sony Taiyo" products.
Isomura: However, the microphone unit was still only at the prototype stage, a very long way from commercialization. Even if we could assume that broadband recording was technically possible, this was the first time Sony had attempted to develop a Hi-Res microphone, so we had to start by ascertaining what actually constituted good Hi-Res sound. Taking our prototype with us, we visited the recording studios of Sony Music Entertainment, and relevant departments handling sound sources at Sony Interactive Entertainment to ask them for their opinions of our sound. We then spent around two years modifying our designs and making a series of prototypes. This was very hard work for the members of our manufacturing team because they produced a huge number of prototypes before arriving at the sound that would become our standard.
Yoshino: We made too many prototypes to count, so that it felt that we spent day after day solely on that task. I have been in charge of professional microphones for many years, including the long-selling ECM-77 Series of pin mic, the ECM-680S shotgun mic, the famous C-38B mic for manzai comic shows, and other units. This experience proved very useful, enabling me to give my opinions to the engineers on how we used such-and-such a process in the case of certain models, or applied certain approaches to stabilizing sound quality.
Isomura: Our objective was to achieve microphones that exceed the C-800G model feature, which is the world standard in Pro-Audio industry much loved by many musicians. The C-800G is so sensitive that its sound characteristics change if the position of an electrode hole differs even slightly, which means that micron-level errors cannot be tolerated during the manufacturing process. We knew it was essential that the new Hi-Res microphones deliver even higher precision than the C-800G, not least of all because studio engineers and musicians would not accept it if it did not. Confident in the skills of the people involved in manufacturing the C-800G on a daily basis, we asked them to manufacture the new units to unprecedentedly high levels.
Yoshino: Mr. Isomura's demands were extremely difficult to satisfy. To ensure the products adhered to hitherto unheard-of levels of precision, we realized we needed to reconsider personnel assignments, and gathered together a team with plentiful experience and knowhow. Some team members with hearing impairments have extraordinary powers of concentration, while Mr. Osako, who is in charge of manufacturing the microphone unit, possesses high-level polishing techniques for dexterously adjusting metals to thicknesses of a few microns. Since sound quality changes if microphone dimensions change by even a micron, we asked him to become a team member to take advantage of his skills in manufacturing the capsule, which is one of the mic unit's key devices.
Osako: One of the components of the microphone unit's capsule is a metal plate, known as a 'back plate.' Hand-polishing is used to make its surface flat, but since this has to be accomplished uniformly at micron-unit thicknesses, the process requires enormous concentration. The capsule also uses sound to check characteristics. Some time ago, Sony Taiyo developed inspection equipment that enables people to check sound quality using charts and waveforms even if they have hearing difficulties. Employees can therefore cover for each other's disabilities as they go about the manufacturing process. This is why I can make the most of my strengths at Sony Taiyo.
Yoshino: The Hi-Res microphone uses four capsules, two for the C-100 microphone and one each for the ECM-100U and the ECM-100N. All are newly-developed. We were concerned about whether we would be able to achieve the required productivity levels and delivery dates on our own because the four types of capsules must be manufactured simultaneously at the mass-production stage. In addition, manufacturing processes and the working environment had to be arranged to suit each disabled team member in order to make the most of their skills. Before mass production could start, daily discussions were held on acquiring the skills and arranging the facilities to suit each individual as we took up the challenge of achieving our dream of creating a new microphone.
Konno: When our Hi-Res microphone was shown as a reference exhibit at the AES Convention held in New York in October 2017, it caused enormous excitement because it was the first new model from Sony since it launched the C-800G 26 years ago. We began to see everyone, from ordinary people to Grammy Award winners, commenting on how good the sound is through SNS and other media. As I witnessed how well the new microphone was received, I realized that this was a product that would add a new chapter to the history that Sony had built up in the area of professional microphones.
Morisaki: Since its founding in 1978, before society was making a real effort to hire the disabled, Sony Taiyo has worked at creating environments where anyone can work, making it a pioneer in diversity initiatives in Japan. Many organizations from all over Japan have made study tours of our company. Since most special subsidiary companies for the disabled are only engaged in manufacturing components, it appears that Sony Taiyo can provide useful reference because its employees take full responsibility for manufacturing finished products.
This latest Hi-Res microphone not only fulfills our dream of producing products that are "Made in Sony Taiyo," but also embodies the company's cherished goal of providing the world with products that are superior to those offered by any other companies. Members of the manufacturing team respond calmly to any request, no matter how difficult the design standards involved. Irrespective of disabilities, this would not be possible without the skilled technologies they apply on a daily basis to manufacturing products that demand high precision.
Yoshino: The very fact that various people are working together makes it possible to create a production environment where they themselves constantly consider how each individual can demonstrate his or her individuality. For example, when employees with hearing difficulties take part in meetings or discussion, other employees with PC condensed transcription or sign language skills take the initiative in providing support. This is a common scene at Sony Taiyo.
Osako: Everyone here sets their own targets and strives to meet them. Whether they have disabilities or not is irrelevant. Manufacturing this Hi-Res microphone involves many difficult factors, but we are so excited to go to work each day with a thought that we are involved with a product that is highly rated around the world.
Morisaki: We constantly and autonomously take up new challenges . Our staff canteen, which is also used as a meeting space, incorporates ideas proposed by everyone as part of an employees' project. I believe the motivation comes from the concept of Diversity & Inclusion, which encourages family-like mutual understanding and respect, and which we were first to adopt.