D. Broadus Keele, Jr., was born in Los Angeles, California, on Nov. 2, 1940. After serving in the U.S. Air Force for four years as an aircraft electronics navigation equipment technician, he attended California State Polytechnic University at Pomona, where he graduated with honors and B.S. degrees in both electrical engineering and physics.
Mountain Home Air Force Base
Boise, Idaho
Mr. Keele worked as an audio systems engineer for Brigham Young University in Provo, Utah from 1969 to 1972, where he received his M.S. degree in electrical engineering in 1975 with a minor in acoustics.
Eyring Science Center at Brigham Young University
Harvey Fletcher and Ted Crowther working in the Anechoic chamber beneath the Eyring Science Center.
Photo: Mark A. Philbrick (Brigham Young University)
From 1972 to 1976, Mr. Keele was with Electro-Voice, Inc. in Buchanan, Michigan, as a senior design engineer in loudspeakers, concentrating on high-frequency horns and low-frequency vented-box loudspeaker systems. He is the primary designer of their “HR” series of constant directivity horns on which he holds the patent.
Electrovoice 1974
For one year, starting in 1976, he worked for Klipsch and Associates in Hope, Arkansas, as chief engineer involved in the company’s commercial line of loudspeakers.
Klipsch Museum of Audio History
Photo: Stacey Svendsen
From 1977 to 1984, he was with JBL, Inc, in Northridge, California, as a senior transducer engineer working on horn and monitor loudspeaker system design. He also holds two patents on JBL’s “Bi-Radial” series of constant directivity horns.
AES 1983 Demo Booth
Mr. Keele was employed by the Techron Division, Crown International, Elkhart, Indiana from 1984 to 1989, where he was Manager of Software Development and responsible for the TEF System 12 Time Delay Spectrometry Analyzer software. While at Techron, he was the designer/programmer for two software packages for the TEF System: EasyTEF, a program for doing general-purpose TDS measurements; and TEF-STI, a program for measuring speech intelligibility.
Crown TEF System 10 (1984)
From 1989 to 2000, he operated his own consulting company, DBK Associates, working primarily for Audio Magazine, Hachette-Filipacchi Magazines, Inc., as their Senior Editor in charge of loudspeaker reviews where he wrote over 80 loudspeaker review articles.
Don Keele with First CBT Prototype 2003 Harman/Becker Automotive Systems
In 1996, he rejoined Electro-Voice, Div. of Telex Communications, as a Senior Research Engineer. In 2000, he joined Harman/Becker Automotive Systems, Martinsville, Indiana, as a Principal engineer in the advanced technology development group where he shared an office with Richard Small (of Thiele-Small loudspeaker parameters fame). At Harman/Becker he added three more patents to his portfolio with two more pending.
In November 2008 he lost his job with Harman-Becker when the plant was closed. Since then, he has resurrected his consulting company, now called DBK Associates and Labs, where he is the principal consultant specializing in loudspeaker horn design, loudspeaker array design, scientific programming, and simulations.
For the last twenty-five years, Don —the inventor of CBT arrays—has been a passionate advocate and evangelist for the technology. He believes that integrating CBT know-how can vastly improve the sound field uniformity across all existing line arrays and loudspeaker systems. See his thorough page on CBTs!
Don’s extensive collection of over sixty technical papers and preprints represents a profound contribution to the field of loudspeaker engineering, spanning topics from fundamental acoustic measurement to groundbreaking loudspeaker array technology. A significant portion of his work focuses on achieving constant directivity and uniform coverage, notably through his pioneering development and patenting of Constant Directivity (CD) loudspeaker horns and, more recently, his comprehensive research into Constant Beamwidth Transducer (CBT) loudspeaker arrays. Keele’s papers also provide critical insights into areas such as low-frequency vented-box loudspeaker systems (including his AES Publication Award-winning work on nearfield sound-pressure measurement), loudspeaker maximum efficiency, and the use of computer-aided design and measurement systems like the TEF analyzer, all aimed at optimizing sound reproduction and system performance across various audio applications. He is a frequent speaker at AES section meetings and workshops, has chaired several AES technical paper sessions, and is a member of the AES review board. Mr. Keele is a past member of the AES Board of Governors and is past Vice President, Central Region USA/Canada of the AES. He is a fellow of the Audio Engineering Society (AES) and a member of the Acoustical Society of America (ASA).
The 74th Scientific & Technical Awards
Friday, March 1, 2002
Mr. Keele received the 2001 TEF Richard C. Heyser Award for contributions to loudspeaker measurements. In 2002 he received a Scientific and Technical Academy Award from the Academy of Motion Picture Arts and Sciences for work he did on Cinema constant-directivity loudspeaker systems and is listed in the AES Audio Timeline where he pioneered the design of constant-directivity high-frequency horns in 1974. Mr. Keele has been married for 41 years, has four children, six grand children, and resides in Bloomington, Indiana, USA (as of July 2010).
