Industry & Product News
Genelec Expands Smart IP Family with Ethernet-Only Loudspeaker and Controller App
Genelec has further expanded its Smart IP family of installation loudspeaker systems with the introduction of a super compact 4410 loudspeaker model and a new Smart IP Controller app. The 4410 joins the existing 4420 and 4430 Smart IP speakers, while the free Controller app provides the end user with instant and intuitive control of key loudspeaker system functions including mute, volume control and power on/off, plus overall zone control. Read More
Dirac Takes Sudio E2 TWS Earbuds a Step Further with Virtuo Spatial Audio
Swedish digital audio processing pioneer Dirac and Sudio, the Swedish consumer electronics design house, announced a collaboration on Sudio’s new flagship E2 true wireless stereo earbuds, featuring Dirac Virtuo spatial audio. Founded in 2012, Sudio sits firmly at the center of Sweden’s visionary audio tech scene, and this collaboration with Dirac for the cutting-edge Sudio E2 earphones reflects the companies’ unrivaled strengths in combining breakthrough sound performance and elevated product design. Read More
New Sennheiser IE 600 Earphones Are Proud to Be Wired and Built to Last
The new IE 600 earphones are the first product from Sennheiser's consumer division - now part of the Sonova group following the acquisition. The model sits between the flagship IE 900 and the IE 300 earphones, both launched in 2021, all designed for music enthusiasts that remain indifferent to wireless options and still believe "the tiniest details count." With the new Sennheiser IE 600, the company also promotes "a lifetime of listening pleasure," in reference to the advanced materials used in the ultra-tough earphone housings. Read More
USound Announces Fully Integrated MEMS Audio Modules for True Wireless Earbuds
USound, the developer and manufacturer of microelectromechanical systems (MEMS) speakers for personal devices and wearables, announced an expanded partnership with Austria Technologie & Systemtechnik (AT&S), a manufacturer of high-end printed circuit boards and integrated circuit substrates, to manufacture USound’s new fully integrated audio module for true wireless earbuds. The new audio modules can be 75% smaller and 85% lighter, with improved sound quality, compared to current TWS solutions. Read More
ROHM Announces New 32bit D/A Converter IC for High-End Audio Products
ROHM Semiconductor announced that it has developed the new BD34352EKV digital-to-analog converter (DAC) IC and corresponding evaluation board (BD34352EKV-EVK-001), supporting playback of high-resolution audio sources in high-fidelity audio equipment. Complementing its latest MUS-IC BD34301EKV flagship DAC, the new product was designed to maximally extract and convert high-resolution digital audio data to analog audio signals in new product designs, particularly new Digital Audio Players and USB-DACs. Read More
Sennheiser Group Invests in Professional Audio as Sonova Completes Acquisition of the Sennheiser Consumer Division
Sonova Holding AG, the Swiss hearing care solutions company, has successfully closed the previously announced acquisition of the Consumer Division from Sennheiser electronic GmbH & Co. KG, creating a new Consumer Hearing business unit. Sennheiser will now focus exclusively on professional audio solutions, keeping Neumann.Berlin as the only separate brand, while the Sennheiser Group aims to achieve sustainable growth. The new Sonova Consumer Hearing business will seek to capture growth opportunities in the fast-growing market for true wireless earbuds, the emerging segment of speech-enhanced hearables, as well as expand Sennheiser’s strong position in "audiophile" headphones. Read More
DiGiCo and d&b audiotechnik Partner on Immersive Audio Technology Integration
Managing an immersive audio production during a live performance is a challenge that is better dealt with directly in the mixing console. But because immersive audio formats continue to rely on external DSP processors, companies need to work together. The German professional loudspeaker company d&b audiotechnik has partnered with DiGiCo, to integrate d&b's Soundscape immersive audio system platform directly into the digital mixing solutions of the British company. Read More
Messe Frankfurt Confirms the End of Musikmesse Trade Show
Top management at Messe Frankfurt is hoping that the pandemic will end soon, allowing the company to return to its normal business activities and generate revenue. While the first trade show to return to one of the world's best fairgrounds will be Prolight+Sound, scheduled for April 26–29 2022, allowing the event and live entertainment industry to celebrate its comeback, Musikmesse will now definitely be left behind. Messe Frankfurt confirms the intention to end the Musikmesse trade show and the associated local festival. Read More
Qualcomm Redefines True Wireless with Two New Snapdragon Sound Platforms
At Mobile World Congress 2022 in Barcelona, Qualcomm announced new options for brands and developers to offer the latest technologies in wireless audio. Qualcomm announced the latest S5 and S3 Sound Platforms with support for new Snapdragon Sound experiences, featuring lossless CD-quality streaming over Bluetooth, stereo recording, ultra-low latency sound with in-game chat, and adaptive active noise cancellation. Both new platforms already offer support for Bluetooth LE Audio. Read More
Guest Editorial
Mike Klasco
(Menlo Scientific)
A Tribute to John Koss
Stereophones and Some Headphone History
Looking back at the history of headphones, it seems as it was just yesterday that everything happened. And while we write frequently about the pioneers who wrote the book on speakers and audio amplifiers, it's not so common we celebrate those with significant contributions to headphones and personal audio technology. Just recently, we lost one of those people, and he should be remembered.

John C. Koss passed away Tuesday, December 21, 2021, at 91.He was Founder and former Chairman of Koss Corp., which introduced the world to headphones for listening to music.

He founded the company in 1953 as the J.C. Koss Hospital Television Rental Company initially to rent television sets to hospital patients. Later in 1957, he partnered with engineer Martin Lange, Jr. and Jerome Kadrich to form the American Development Corp. where they manufactured a television tube checking device that Lange had designed for use in drugstores.

Koss and Lange’s next adventure was to develop a stereo portable phonograph player. The design was uniquely bundled with a privacy headphone accessory to demonstrate to consumers the stereo sound of the portable phonograph... thereby inadvertently creating the global consumer stereo headphone industry. The SP/3 headphone was initially kluged together from speakers, cardboard, foam and other spare repair parts from their TV service department. That model has had a place in the Smithsonian Institute since 1972.
In 1958, John C. Koss teamed up with engineer Martin Lange, Jr. to develop a portable stereo phonograph player with side-wing speakers. The system was demonstrated with stereophones, activated through a "privacy switch." The accessory to demonstrate the high-fidelity stereo sound became the actual success story.
While French engineer Ernest Mercadier was awarded US Patent No. 454,138 for a headset for telephone operators in 1891, American engineer Nathaniel Baldwin invented something described as "the headphones," later in 1910, which he built at his kitchen table, and supplied to the US Navy for radio communications. The first "headphones" for use in broadcast and music recordings are associated with the famous DT 48 (DT = Dynamic Telephone) in 1937, and came from Eugene Beyer, a refugee of the Russian revolution living in Germany.

But back to Koss, who also started his headphone project from humble manufacturing and marketing beginnings - from his basement apartment. From that first experiment with the successful SP/3 stereo headphones, Koss would quickly be recognized in the segment and become one of the first brands associated with headphones for music. The more developed Pro/4 Series was launched in 1962 and became the recording industry standard, and later the official headphones of Air Force One. John Koss went on to help standardize the 1/4" plug and headphone jack we take for granted today.
In 1958, listeners could finally hear music with the world's first Koss SP/3 stereophone.
John C. Koss in 1970. With little serious competition, Koss Corp. made headphones popular for the baby boom generation, and Koss himself worked tirelessly to promote his product against Japanese inexpensive headphones.
In late 1964, Koss branched out with the acquisition of Rek-O-Kut, which developed and built phonograph record-cutting lathes and broadcast and audiophile manual turntables. By the early 1960s, Rek-O-Kut was facing tough competition in turntables from the German dual automatic turntables, and also the Swiss-German made Thorens TD 124, which was quite superior reaching the US through ELPA marketing, a very effective distribution company.

Rek-O-Kut's record-cutting lathe side of the business was also facing challenges from both big (Westrex) and small but innovative competitors. By the end of 1964, the owners sold Rek-O-Kut to Koss and the factory was moved from Queens, NY to the Koss operation in Milwaukee, WI. By 1970, the consumer audio market for bulky belt drive manual turntables was gone and Koss sold Rek-O-Kut to CCA, a broadcast station equipment manufacturer.
When John C. Koss purchased control of Rek-O-Kut, he discussed "quality" with Sid Simonson (Rek-O-Kut Manufacturing Vice-President) and Hal Dennis (Rek-O-Kut Sales Vice President). "There's a reason why everyone thinks of Rek-O-Kut as the very finest in single-play turntables. There's a reason why every audio engineer in the business knows and respects Rek-O-Kut equipment," said Koss. "The reason," Simonson explained, "is that for over 25 years, we paid particular attention to purchase of parts and raw materials. Then we tooled for absolute precision in machining and assembly. If something wasn't perfect, we scrapped it!" - "Good." said Koss, "that's what I do with our headphones and that's what I want continued with our turntables."
Back then, Koss Electronics lead an investment group that approached Arthur Janszen, of Janszen electrostatic fame. Old timers may remember the AR-1 acoustic suspension woofer, which was often paired with the Janzen Z-130 electrostatic array for the mids and highs. Arthur Janszen’s next big thing was the KLH 9 full range electrostatic speaker panels. After Janszen left KLH, Koss approached him with a project for the next generation of electrostatic panels. This would become the Acoustech X from Acoustic Technology Laboratory, Inc., later the Acoustech Division of Koss Electronics. A combination of somewhat larger area panel size and maybe increased plate spacing gave Acoustech X a bit more bass than the KLH 9.

I remember working after classes while at New York University, at Harvey Radio, which had a pair of these speakers. It was bi-amplified with one of the first solid-state amplifiers boasting silicon transistors (or at least when they could get hold of such esoteric semiconductors), otherwise with germanium transistors, which would more than occasionally blow up). In 1973, Marty Lange purchased the Acoustech Co. from Koss. Lange stayed actively involved in many aspects of the Koss business for more than 50 years.
Acoustech X (Acoustic Technology Laboratory, Inc.) full-range electrostatic speakers, designed by David Janszen. The speakers would have a solid-state high-fidelity amplifier incorporated and were promoted as a system by the Acoustech Division of Koss Electronics.
Around 1968, Koss pioneered the high-end "electro-static" ESP/6 headphones. These headphones set the standard for wide-range frequency response and were insanely expensive at about $170. Uniquely self-energizing, the bias current for the electrostatic drivers was derived from the audio signal tapped off your amplifier speaker outputs. When first turned on, it took a few moments to “come up” and also suffered bias starvation during quiet passages. These problems were soon resolved the next year with the ESP/7, and in 1971 with the much improved ESP/9.

The year 1974 saw the HV/1A, Koss’s answer to a dynamic headphone with the bandwidth of their electrostatics. The dynamic speaker elements found in Koss Headphones today are a direct evolution from the legendary HV/1A. Since the Pro/4AA, launched in 1970, Koss was recognized for the performance from its dynamic professional headphones. The HV/1A took dynamic headphones to high-fidelity status. The unmatched sound, and modern dynamic speaker elements found in Koss headphones today are a direct evolution from the legendary HV/1A.
In 1968, Koss released the ESP/6, the world’s first self-energizing electrostatic headphones. The Koss ESP 6 had the charge applied to push-pull condenser plates, which caused movement of an ultra-lightweight conductive diaphragm. The ESP/9 model (pictured) followed in 1971.
These are the "modern" Koss ESP950 Over Ear Electrostatic Headphones ($999.99 retail) introduced in 1990 and featuring ultra-thin (1.5 micron) diaphragms.
Seeing the miniaturization of electronics in the 1980s, John Koss pushed his company to develop “portable” headphones for on-the-go listening. The result was the Koss Porta Pro, a collapsible headphone that was the template for today’s on-the-ear headphones. And in 1989, the Koss JCK/300 cordless headphone was developed using infrared wireless headphones. By developing a new transmitter that delivered more power than conventional infrared headphone systems, Koss cut the cord.

Beyond the business side of consumer audio, John and Walter Stanton (of Stanton-Pickering phono cartridge fame) were pivotal in founding the Institute of High Fidelity, with John Koss as vice president in 1965. IHF standards for audio power output and other specs were often adopted by other industry organizations. In 1979, John Koss was inducted into the Audio Hall of Fame. And again in 1995, he was inducted into the inaugural class of the Electronic Industries Association (EIA) Consumer Electronics Hall of Fame. I might mention that the EIA (later renamed the Electronic Industries Alliance) absorbed the Institute of High Fidelity in 1979 but seemed to have misplaced it, sort of like the “Lost Ark.” (EIA ceased operations in 2011.)

In the 1980s, John Koss and the company contributed to the Medical College of Wisconsin to develop the Koss Hearing and Balance Center, along with the Koss Cochlear Implant program. This relationship ultimately led to the John C. Koss Endowed Chair in Otolaryngology. In 2007, Koss received an Honorary Doctor of Science Degree from the Medical College of Wisconsin and the Seymour Cray Award for Distinction in Technology presented by the Wisconsin Historical Society and the Wisconsin Business Hall of Fame.
As Sony conquered the world with the Walkman portable cassette player, released originally in 1979, Koss introduced its own version of light headphones for portable personal listening, first in 1982 with the Koss MusicBox portable AM/FM radio, and in 1984 with the acclaimed Koss Porta Pro, which continued to be one of the most popular headphones around the world and are still available today.
In the words of his son Michael J. Koss, who took over as president and chief executive officer in 1991, “Ask anyone who knew my father, and they’ll tell you he was one of a kind. He distinguished himself as an eternal optimist that never let anything stand in his way. We’re all proud of his achievements, not just with the Koss Corporation, but through the contributions he’s made helping others. John C. Koss made the world a better place. We’ll miss him dearly.”

John C. Koss will be probably remembered first and foremost for his contributions to headphones and more recently for having contributed to the popularity of robust, affordable, and great value products like the Koss Porta Pro, which remains a popular option for personal audio even today. Not always obvious, but not so long ago, listening to "stereo" music on headphones was a strange concept. And Koss took the concept and made it portable and personal.
R&D Stories
The Arrival of Spatial Room Correction Technology
By Lars-Johan Brannmark (Dirac)
n this exclusive article for audioXpress, Lars-Johan Brannmark (Chief Scientist, Dirac Research AB) describes an approach to the challenge of applying DSP room correction to complex multichannel setups, intended for immersive audio reproduction. Instead of one filter applied to a single channel, he proposes a solution where all speakers work to optimize the reproduction of each input channel in an optimal way. Written from the perspective of the Swedish digital signal processing specialist company that created one of the market's leading room-correction solutions, the article anticipates an important requirement for the evolution of room correction. This article was originally published in audioXpress, December 2021.  Read the Full Article Now Available Here
Voice Coil Test Bench
The 10NW76 Pro Sound High SPL 10” Driver from B&C Speakers
By Vance Dickason
The driver on this Test Bench is the 10NW76 high-SPL 10” woofer from B&C Speakers, clearly designed for professional audio and - rated at 400W (800W continuous) - is the highest power handling 10” in the B&C Speakers line-up. The 10NW76 was designed for uses in line arrays, small two-way monitors, and as a subwoofer, or as a midbass driver in multiway systems. The 10NW76 uses a proprietary 12-spoke (six double spokes) cast-aluminum frame with a series of cooling vents that allow air to move past the voice coil and across the front side of the neodymium motor assembly. Additional cooling is provided in a tapered and flared 1.5” diameter pole vent in conjunction with eight 6.5mm diameter peripheral vents located on the milled back plate. The cone assembly consists of a curvilinear waterproof coated paper cone and dust cap, with compliance supplied by a pleated coated polycotton cloth three-roll-type surround and from a cloth type 5.5” diameter flat spider. This article was originally published in Voice Coil, December 2021. Read the Full Article Now Available Here
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