Koss

Lore & Background

John C. Koss founded the J.C. Koss Hospital Television Rental Company in 1953. Seeking new ideas, he partnered with engineer Martin Lange to develop a stereo headphone, which arose almost by accident from an attempt to market a portable phonograph. The headphone's privacy switch allowed listeners to hear the Koss SP/3 Stereophones, initially intended to demonstrate the portable phonograph's high-fidelity stereo sound. The design debuted at a hi-fi trade show in Milwaukee in 1958, where audiences approved, and Koss soon began manufacturing stereophones from his basement apartment. The technology was quickly imitated by competitors.

In the early 1970s, Koss operated from two nearby locations in Milwaukee: a TV-rental site that also handled electronics and musical instrument repairs, and a main facility two blocks east. During this period, Koss pioneered the high-end electrostatic 'ES series' headphones, setting a standard for wide-range frequency response. Koss headphones were durable and cost-effective to repair, with service provided by K&M Electronics. The TV rental and repair site was managed by John's brother Pete Koss. Koss eventually dominated the headphone market, competing mainly with Telex and offering a wide line of models considered higher quality.

In the late 1970s, Koss moved to its present location on Milwaukee's north side. The 1980s saw unsuccessful diversification into related electronics, leading to a net loss of US$6 million in 1984 and a Chapter 11 bankruptcy filing; the company emerged in 1985. In 1991, Michael J. Koss, son of the founder, became president and CEO. In December 2009, former vice president of finance Sujata 'Sue' Sachdeva was charged with wire fraud for embezzling US$34 million; she was sentenced to eleven years in federal prison and served six. Koss restated five years of financials and recouped over US$12 million. In 2020, Koss sued Apple, Bose, and others for patent infringement, settling with Apple in July 2022 for an undisclosed amount. During the 2021 GameStop short squeeze, Koss executives and directors earned US$40 million by selling company stock.

Reader's Guide

Koss Corporation holds a foundational place in consumer audio history as the company that introduced the first high-fidelity stereo headphones in 1958, transforming headphones from a niche communications tool into a device for personal music listening. The company's early success was driven by a combination of accidental innovation—the headphone was a byproduct of marketing a portable phonograph—and strong market reception at a Milwaukee trade show. Koss's electrostatic ES series in the 1970s set benchmarks for frequency response, and its durable, repairable designs helped it dominate the headphone market against competitors like Telex. The company's longevity is marked by both resilience and controversy: it survived a 1984 bankruptcy and a 2009 embezzlement scandal involving US$34 million, from which it recovered over US$12 million. Its 2020 patent infringement lawsuits against major audio companies, including Apple, underscore its ongoing assertion of intellectual property rights. Koss headphones have been sold under its own name and through retailers like RadioShack, and since 1989 all North American-manufactured models carry a limited lifetime warranty. The company remains majority-owned by the Koss family, with Michael J. Koss leading since 1991.