[Editor’s Note: A version of this story appeared originally in the August 2025 issue of Mix.]

Tom Hidley. A storied name in the professional audio industry. A giant who kept a low profile. He was always mannered and soft-spoken, allowing his amazing legacy of work—from technology development to studio design—to speak for itself. In early May 2025, just shy of his 94th birthday, Hidley passed away quietly at home in Bangkok, Thailand.

Born in Los Angeles, Calif., in 1931, Hidley’s first passion was music. An accomplished saxophone player while still a teenager, he quickly picked up the clarinet and flute, pursuing his passion for playing with such intensity that it ultimately affected his health. His new passion became the technology of sound recording and reproduction.

After a few early years working at loudspeaker and tape machine companies, while recording remotely at night in area clubs, Hidley began a six-year stint at JBL in 1956, tackling product performance evaluation as well as installing high-end consumer playback systems for the likes of Frank Sinatra and Lucille Ball.

When Val Valentine, chief engineer at MGM/ Verve, relocated from L.A. to New York, he invited Hidley along, introducing him to the world of recording studios and record labels. There, Hidley assisted in four rooms on Broadway in 1962, staying on to serve as an engineering tech and as head mixer for MGM/Verve house producers.

The legendary Phil Ramone hired Hidley in 1964 as audio technical manager of A&R Recording in Manhattan. Speaking with Chris Stone, a fellow Record Plant alum, Hidley recalled that his quest to extend the low-end of studio monitors, at a time when standard speakers of the day only went down to 63 Hz, began with Ramone.

“Phil kept saying that something wasn’t right on the bottom end, and he was right,” Hidley recalled. “Acoustic instruments require 40 Hertz at the bottom end for monitoring.”

In 1965, Hidley and Amnon “Ami” Hadani, a co-worker at both MGM/Verve and A&R, left New York for Los Angeles to found TTG Studios. Expanding on the speaker designs he’d experimented with while at A&R, Hidley soon built a series of large, custom two-way monitors with dual woofers that extended down to 40 Hz.

During that time, Hidley noticed the space stressing as big band sessions reached 107 dB SPL. Soon, rock ‘n’ roll bands with just five players would take it up to 120 dB SPL. To help tame the untreated space, Hidley came up with a number of acoustic innovations, including the addition of drum kit and bass platforms floated on coil springs above the diaphragmatic studio floor.

Meanwhile, in 1967, Hidley also developed the world’s first 16-track, 2-inch tape machine, again creating a buzz and driving artists to the studio.

RECORD PLANT TO WESTLAKE

Hidley’s studio design career truly began with the 1969 opening of The Record Plant Los Angeles. He would later become Director of Technical Operations for all Record Plant facilities, but most of his acoustic innovations came out of L.A., including the first three-angle control room front wall and window system; flush-mounted control room monitors; the development of membrane bass traps and coining of the terms “trap” or “bass trap”; an “open” studio drum cage to enhance track separation; and sliding glass doors between studio and iso rooms to accommodate isolation or provide main studio extension.

He answered the demand for more tracks by building the first 24-track, 2-inch tape recorder in commercial operation. The linear 38Hz monitors he designed for the studio became popular worldwide, with more than 2500 eventually sold.

In 1969, while still at The Record Plant, Hidley formed Westlake Audio to sell packaged electronics—the entire mic-to-monitor recording chain—out of his Westlake Village home. After he left The Record Plant in 1971, he and his partners set up Westlake as a one-stop shop on Wilshire Boulevard, where Hidley designed rooms, sales people packaged the gear, and dedicated construction teams built the clients’ studios.

After completing three European studios in 1974 and ’75, Hidley sold back his share and moved to Switzerland to form Eastlake Audio, continuing his design work and monitor sales, but by 1980, convinced that he could not progress his designs any further, he retired to Hawaii.

It didn’t last. Gleaning insights from beach meditations, he developed an acoustic room design concept that he called “the non-environment room.” In 1986, inspired by results from a prototype studio built in Tokyo, Hidley returned to Switzerland and set up as Hidley Design.

THE NON-ENVIRONMENT ROOM

The non-environment room was conceived to remove the impact of the room by presenting a nearly anechoic space to the loudspeakers. “Diffusion equals confusion,” Hidley would often say. The solution began with analysis of the interaction between the physics of the space and the performance of the speaker.

Hidley developed a relationship with Pioneer design engineer Shozo Kinoshita, who had developed a new vertical monitor with a TAD compression driver and a wide, bespoke hardwood horn between a pair of TAD 15-inch woofers. The monitors would be surrounded by four inches of concrete, with concrete in-filled down to the base of the monitor wall’s wood frame, resulting in zero acoustic energy being wasted driving the walls.

Outside of Japan, the speakers were sold only as a package with a room designed to Hidley’s specifications by architect Thomas Rast, and acoustics and implementation by Hidley crews. Leading Hidley Design’s construction teams across three decades was builder Michael Cronin.

“Tom was a genius whose body of work is staggering,” Cronin says. “He was generous with his knowledge, and his standards and work ethic were inspirational. He became something of a father figure to me, far more than a boss and friend, though he was both of those as well.”

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For more than 30 years, Hidley continued to refine his non-environment designs and worked to push low-frequency performance of larger spaces down to 10 Hz. Concepts he developed continue to drive modern studio design, and his non-environment principles are taught academically.

Second retirement found Hidley and his wife and steadfast companion, Dawnette, in Thailand, where he passed May 2, 2025, nearing his 94th birthday. He is survived by his wife, a son, daughters, grandchildren and great-grandchildren.