Clifford A. Henricksen

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Clifford A Henricksen
Clifford A Henricksen.jpg
Henricksen September 2014
Born (1943-07-12) July 12, 1943 (age 80)
Kew Gardens, Queens
NationalityUS Citizen
Education MSME
Alma mater Union College, Schenectady NY
Massachusetts Institute of Technology, Cambridge Massachusetts
Occupation(s)Inventor, musician
Known for Acoustical engineering
Spouse(s)Bonnie née Zimmermann
(1967–present)
Website cliffmics.com
Signature
Image of Cliff Henricksen's signature.png

Cliff Henricksen is a musician, inventor and audio technologist. He is self-taught as a musician with a graduate degree in mechanical engineering at Massachusetts Institute of Technology (MIT). Throughout his career Cliff has found innovative ways to apply engineering basics to electro acoustics and to audio technology as it applies to music and in particular to live music performance. He has invented and engineered a wide variety of technologies and products well known in the world of professional audio. Today he balances work in audio and work as a performing musician.

Contents

Cliff Henricksen was born on July 12, 1943, in Kew Gardens on Long Island NY, the son of Norwegian immigrant Birger ("Bill") and Alice (née Totland) Henricksen, and grew up in Elmont, New York. His father's early career was as first-engineer on ocean-going ships for the Moore McCormack Company. He subsequently took a land-based day job as a mechanic and welder in order to participate more actively in home and family life. He also became an accomplished musician, playing accordion, drums and fiddle, and performing as a well-known square dance caller with a country music band called "The Ranch Boys". He also played drums at nightclub gigs and was bandleader of his own "society orchestra" that played events in venues like New York City's Waldorf Astoria Hotel. It was his father's facility with all things mechanical, as well as his love of music and his fascination with the technology behind the music, which was the single most important influence in Cliff's formative years.

Microphones, PA systems, home hi-fi systems, and tape recorders were a constant and ever-evolving part of the Henricksen household and played a significant role in shaping Cliff's technical and artistic sensibilities. By the time he got to graduate school at MIT, Cliff was playing regularly with a Boston-based cover band while still managing to make it to his 8 a.m. engineering lectures. He also met his future wife, then Bonnie Zimmermann, and together they started a family that grew to include 9 children (5 boys and 4 girls). Today Cliff and his wife Bonnie make their home in Framingham MA.

Code of Work

Cliff began his career in professional audio by starting a research group at Altec Lansing in Anaheim CA in 1974. In the course of that work he met and became friends with Bill Putnam and Allen Sides, both of whom became important inspirations for achieving a balance between audio aesthetics and engineering excellence. Putnam's work on the UREI Time Align studio monitor loudspeaker, and Side's work through his Ocean Way studio business (then operating out of a garage in Santa Monica CA) were fundamental and profound influences in showing Cliff how to listen diagnostically to the audio qualities of speakers, microphones and music electronics generally. The importance of "audio aesthetics first" has been a guiding principle in all of Cliff's work since that time.

Because of this code of work and his experience as a performing musician, Cliff is one of the few audio professionals able to voice major arena sound systems by ear and to develop L1 and T1 "Tone Match" presets for Bose Corporation strictly by listening.

Experience

A lifelong musician, Cliff Henricksen is aware of the importance of the musical arts and their benefits to society that transcend technology. As an experienced player and composer, he knows this from a true artist's perspective. As an MIT-educated scientist and engineer he has also made it his life's work to bring innovation to the technology associated with the business of professional audio and musical performance.

He has held key senior technical positions at Altec Lansing (Anaheim CA), Community Professional Systems, Electro-Voice, US Sound and Bose Corporation, where he was a key contributor to the invention, development and commercial launch of breakthrough technologies and products that have advanced and inspired the art of live music and professional/engineered sound for over 40 years. In doing so, he was able to contribute directly to enhanced market presence and increased business for his employers.

He was co-owner of US Sound, a "super contractor" with a patented and proprietary sound system components and overall system concept of his creation. It was called "Coherent Zone Technology". Engineered systems were installed, first, in the OMNI Arena (Atlanta) and later at Madison Square Garden (New York City) and used for many years for normal MSG events of all kinds. A road system was developed for The Judds and for solo shows of Wynonna Judd, mixed by house engineer John Cooper, and for Bruce Springsteen in collaboration with Audio Analysts of Colorado Springs. US Sound was sold at its prime to Bose Corporation where its product line (renamed "Panaray LT") still is the mainstay of Bose's large-venue engineered sound business. At Bose, Cliff went on to invent the famous "L1" line array and co-developed technologies and methodologies used in current "Room Match" and "Show Match" systems.

After a long career working for well-known professional audio companies Cliff started Cliff Innovations LLC in Framingham MA, where he developed new electroacoustic technologies and new, advanced ribbon microphone concepts, for use in recording and broadcasting. Using the new concepts for ribbon microphones, he later started the "Cliff Mics" company and introduced the RM1 ribbon microphone to the professional market at the summer Audio Engineering Society's 2014 convention in Los Angeles. This microphone used large Neodymium magnets to achieve unprecedented raw transduction sensitivity. Also, a unique phantom-powered preamplifier with proprietary voicing gave the microphone a sound presentation similar to large-diaphragm condenser microphones but having the well-known dynamic qualities unique to ribbon microphones. At this show, he was reunited with old friend Allen Sides, Grammy-winning owner of famous Ocean Way recording studios and Ocean Way Audio. Allen listened to the mic at the show. Amazed at what he heard, he offered to help Cliff promote and distribute the microphone. Cliff in turn offered to help Allen with new original loudspeaker designs. And so, they formed a "strategic alliance" defined by a personal contract, which is in place as of this writing (8/4/2021)

Today, Cliff also remains active as a recording and performing musician/composer with his band Wachadoo (www.wachadoo.com). Current recordings including unique all-ribbon recordings using prototype microphpones for kick drum, snare and stereo/overhead.

Cliff's US patents include 7,936,891 B2; 7,260,235; 7,319,767; D249,509; 3,991,286; 4,050,541; 4,187,926; 4,130,023; 4,811,403; and UK 1,514,007.

Cliff is widely published in a range of well-known and respected technical papers, periodicals and books.

Cliff was honored as a Fellow of the Audio Engineering Society, [1] appointed a Kentucky colonel (by the Governor of Kentucky for his contributions to the amplified musical arts) [2] and included in the Electronic Musician's "Hall of Fame" for his basic invention of the Bose L1 line array for live performance. [3]

Education

Professional Appointments

Professional Milestones (Reverse Chronology)

Ocean Way Audio LCR AeroWave sound system for Granada Theater, Santa Barbara CA – Designer, mechanical engineer, acoustical engineer. 3: 90 x 90 degree fullrange high-fidelity high-efficiency directivity-control systems each cover the entire room/balcony for stereo everywhere (a first in large-venue sound) Basic acoustic design. System design, commissioning and voicing by Allen Sides and Bruce Marian.

Ocean Way Audio AeroWave large-venue sound system technology – Inventor, developer

Ocean Way Audio HR5 Studio Monitor– Smaller version of HR4, same wide stereo zone. Basic acoustic design. LF and overall system design and voicing by Allen Sides and Bruce Marian.

Ocean Way Audio HR3.5 Studio Monitor – Triamped variant of HR4 with dual 12” woofers for extended low end. Basic acoustic design. LF and overall system design and voicing by Allen Sides and Bruce Marian.

Ocean Way Audio HR4 Studio Monitor – 100x 40 degree system with extremely wide stereo listening zone (eliminates “sweet spot” present in all direct-radiator monitors). Basic acoustic design. System design and voicing by Allen Sides and Bruce Marian.

Ocean Way Audio RM1b Studio Microphone – Updated version of the RM1. “Ribbon Safe” and other improvements for shipping protection, improved grille, some aesthetic changes.

Ocean Way Audio, Director, New Technology: heading up the new products development team, building on the platform established with the No Limits HR series.

Cliff Mics , a DBA division of Cliff Innovations LLC: Developed the RM1 advanced-technology ribbon microphone.

Bose Corporation “Room Match” engineered sound system: Many in-development/patents-pending (confidential). Co-inventor of the basic electroacoustic technology and means of creating flexible, scalable sound systems using parametric n/c machining and related business-system techniques and unique assembly methods.

Bose Corporation L1® family: Builder/first-live-music-user of first L1 prototypes and inventor of core L1 technologies and methodology [7] [8] , collaborating with Ken Jacob of Bose. Creator of and naming of "Tone Match" instrument/delivery system integration used on all L1 and T1 products, creator of most "ToneMatch" voicing filters by ear, often in collaboration with major instrument makers and microphone manufacturers. Creator of a large volume of support copy, used in advertising of all kinds. Responsible for engineering development and personal use of the first prototype systems. (This overall concept is changing the entire culture of live amplified music.) Held keyboard/vocal chair for the duration of the "Linemen" L1-demo band, this band actually being built around the L1 with local "A-list" players. Many concerts stunned audiences with superb musicianship, arrangements and sound quality in the US, Canada and Europe. Countless concerts were performed in Bose Corporation's own auditorium and live-music theater, where Cliff also performed solo during these shows, playing piano and singing, often performing his own compositions.

Bose Corporation MA12 and MB4: Early spin-offs of the L1 program, before it became such. These components are still mainstays of the engineered sound product line.

Bose Corporation Panaray LT family: Design of core arraying loudspeaker family for high-end large-venue sound including invention and engineering of “V4” manifolded midrange driver.

Bose Corporation sound system for the Holy Mosque, Mecca : Designed a unique horn-waveguide system for this acoustically-challenging, aesthetically-demanding all-marble facility.

Bose Corporation arena sound systems (GM Place/Vancouver BC, Staples Arena/Los Angeles CA, Air Canada Centre/Toronto ON): Internal design consultant and final in-situ system voicing/commissioning by ear.

Universal Islands of Adventure, Orlando FL (for Bose) : Inspired dock-piling-themed line array systems and voiced all sound zones by ear, with Bruce Myers, on startup of this facility.

Fender Musical Instruments Passport PD150 and PD250 systems: Basic electroacoustic concept invention and development of first working prototypes (Part of a Bose/Fender collaboration)

Audio Analysts/Bruce Springsteen Systems – Collaboration with co-owner Albert Leccesse on a very high acoustic output, exceptionally clear monitor speaker for the artist, based on the US Sound CZ44 (now Bose LT4402). Also, design and use of a wide-angle end cluster for shows at the unusually-long Wembley Arena in the UK.

US Sound Coherent Zone Loudspeaker family: Invention, component and system design, production engineering, technical support.

US Sound Arena Sound Systems (The OMNI/Atlanta GA, Madison Square Garden/NYC NY): System concept, design (first “exploded-cluster” arena system in America), installation engineering and supervision, final system voicing by ear. Systems sold directly to the arenas.

US Sound Touring Sound System for The Judds/Wynonna Judd : First “Coherent Zone” sound system design including first high-directivity mid/high, 18” bass system and very low-profile stage monitor for improved visual qualities.

Electro Voice MT™ Manifold Technology sound reinforcement system: Basic research and invention leading to this breakthrough, multiple manifolded-driver product design. This work and product concept inspired a number of new ideas (throughout the industry) in systems concepts and designs.

Electro Voice HP horns, DL woofer family, DH1 compression driver: Engineering management of the team to produce these component series, contributed many innovations.

Community M4™ midrange driver: Developed basic equations of operation including the phase plug and motor design, co-developed the product, authored several technical and technical/marketing papers and articles.

Altec Lansing Manta Ray Horn family: Invention, patenting, co-development and design of large- and small-format horns for various coverage patterns and uses, including consumer hifi.

Altec Lansing Tangerine Phase plug family : Invention, patenting, design, prototype building and production engineering of 3 phaseplugs for 2.83”, 1.75” and 1.75” piezo-driven diaphragms (“LZT” driver for consumer systems). Developed original equations of operation and co-authored patent and technical articles. Also gave it the name, earning a distinct market awareness.

Altec Lansing Auto-Q automatic directivity measurement technology : Inventor, patented.

Altec Lansing Voice of the Highway system for automotive sound systems: Gave it the name, based on the iconic “Voice of the Theater”.

Patents

Clifford A. Henricksen

  1. US Patent 11,058,394 "Stethoscope" (novel passive medical stethoscope including self-sterelizing variant, with MD's Peter and Carla Faulkner/Innovative Medecine Partners, Mobile Alabama)
  2. US Patents D830342 D837183 D871370 (Ocean Way Audio studio monitor loudspeaker systems)
  3. US Patent 7,936,891 B2 (Bose L1 Model2 “articulated array”) [9]
  4. US Patent 7,260,235 (Line electroacoustical transducing – Bose L1 line array for live music) [10]
  5. US Patent 7,319,767 (Line array electroacoustical transducing – Overall mechanical arrangement of Bose L1 model 1) [11]
  6. US Patent D249,509 (Acoustical transformer for coupling sound waves from the diaphragm to the throat of a horn-type loudspeaker ) [12]
  7. US Patent 3,991,286 (Heat dissipating device for loudspeaker voice coil ) [13]
  8. US Patent 4,050,541 (Acoustical transformer for horn-type loudspeaker Altec "Tangerine " phase plug) [14]
  9. US Patent 4,187,926 (Loudspeaker horn Altec "Manta-Ray" diffraction-slot constant-directivity horn) [15]
  10. US Patent 4,130,023 (Method and apparatus for testing and evaluating loudspeaker performance Auto-Q directivity measurement method) discussed in above paper [16]
  11. US Patent 4,811,403 (Ultralight loudspeaker enclosures US Sound/Bose Corporation lightweight loudspeaker systems construction method) 3/7/89 [17]
  12. Other patents pending

Technical Publications

Clifford A. Henricksen

  1. "Loudspeakers Enclosures and Headphones", Handbook for Sound Engineers-The New Audio Cyclopedia, Howard W. Sams Co. 1987 [18]
  2. "Sound Reinforcement in the Year 2000" [19]
    • a) Invited paper, presented at the 6th International Audio Engineering Society (AES) Conference on Sound Reinforcement, May 5–8, Nashville TN, Proceedings published March 1989
    • b) Presented at the Altec Lansing All-Technical Engineered Sound Conference October 16–17, 1988, Montreal Quebec Canada (Invited paper)
  3. "Heat Transfer Mechanisms in Loudspeakers; Analysis Measurement and Design" Journal of the Audio Engineering Society, vol 35, no.10, October 1987 [20]
  4. "Directivity Response of Single Direct-Radiator Loudspeakers in Enclosures" Altec Technical Letter 227 [21]
  5. "Phase Plug Modelling and Analysis: Circumferential Versus Radial Types" Presented at the 59th Convention of the AES,Hamburg, Germany, March 1978, AES preprint 1328(F5) [22]
  6. "The Manta-Ray Horns" (co-authored with Mark Ureda), Journal of the Audio Engineering Society, vol 26 no. 9, September 1978 [23]
  7. "Auto Q: A New Directivity Measurement System" Presented at 60th AES Convention, May 1978, Los Angeles, AES preprint 1360(F6) [24]
  8. "Vented Box Design Method for Altec Low-Frequency Loudspeakers" Altec Technical Letter 245
  9. "Ultimate Performance of Wide-Range High Frequency Compression Drivers" Journal of the Audio Engineering Society vol 24, no. 8, October 1976 [25]
  10. "Engineering Justifications for Selected Portions of the AES Recommended Practice for Specification of Loudspeaker Components" Presented as the 72nd Convention, October 1982, Anaheim CA, AES reprint 32(G10) [26]
  11. "Sound System Design Using Mechanical Specifications of Drivers" Syn-Aud-Con Tech Topics vol 11 no.2
  12. "A High-Efficiency One-Decade Midrange Loudspeaker" (co-author with Bruce Howze) Paper on the Community M4 driver-Presented at the 70th convention, New York, October 1981, AES preprint 1848(D8) [27]

Periodical Publications

  1. "State-of-the-Art Specs,Finally!" Sound and Video Contractor, September 1984
  2. "Low-Frequency Driver Performance" Sound and Video Contractor, June 1986 [28]
  3. "Unearthing the Mysteries of the Leslie Cabinet" Recording Engineer/Producer, April 1981 [29]
  4. "Designing a Conical Bass-Horn Control Room" Recording Engineer/Producer, March 1987 [30]
  5. Guest Editorial-"No Sweat, No Music – A Player Laments the Spread of Computer Dependency" Keyboard Magazine, August 1985 [31]
  6. "Jammin' in the Rockies – Rediscovery of the Ancient Roller Playground" Skateboard Magazine, October 1976
  7. Book Review of "Loudspeakers" edited by John Borwick, Sound and Communications Magazine, March 1989.

Books

Related Research Articles

<span class="mw-page-title-main">Subwoofer</span> Loudspeaker for low-pitched audio frequencies

A subwoofer is a loudspeaker designed to reproduce low-pitched audio frequencies, known as bass and sub-bass, that are lower in frequency than those which can be (optimally) generated by a woofer. The typical frequency range that is covered by a subwoofer is about 20–200 Hz for consumer products, below 100 Hz for professional live sound, and below 80 Hz in THX-certified systems. Thus, one or more subwoofers are important for high-quality sound reproduction as they are responsible for the lowest two to three octaves of the ten octaves that are audible. This very low-frequency (VLF) range reproduces the natural fundamental tones of the bass drum, electric bass, double bass, grand piano, contrabassoon, tuba, in addition to thunder, gunshots, explosions, etc.

<span class="mw-page-title-main">Loudspeaker</span> Converts an electrical audio signal into a corresponding sound

A loudspeaker is an electroacoustic transducer that converts an electrical audio signal into a corresponding sound. A speaker system, also often simply referred to as a speaker or loudspeaker, comprises one or more such speaker drivers, an enclosure, and electrical connections possibly including a crossover network. The speaker driver can be viewed as a linear motor attached to a diaphragm which couples that motor's movement to motion of air, that is, sound. An audio signal, typically from a microphone, recording, or radio broadcast, is amplified electronically to a power level capable of driving that motor in order to reproduce the sound corresponding to the original unamplified electronic signal. This is thus the opposite function to the microphone; indeed the dynamic speaker driver, by far the most common type, is a linear motor in the same basic configuration as the dynamic microphone which uses such a motor in reverse, as a generator.

Bose Corporation is an American manufacturing company that predominantly sells audio equipment. The company was established by Amar Bose in 1964 and is based in Framingham, Massachusetts. It is best known for its home audio systems and speakers, noise cancelling headphones, professional audio products and automobile sound systems. Bose has a reputation for being particularly protective of its patents, trademarks, and brands.

<span class="mw-page-title-main">Sound reinforcement system</span> Amplified sound system for public events

A sound reinforcement system is the combination of microphones, signal processors, amplifiers, and loudspeakers in enclosures all controlled by a mixing console that makes live or pre-recorded sounds louder and may also distribute those sounds to a larger or more distant audience. In many situations, a sound reinforcement system is also used to enhance or alter the sound of the sources on the stage, typically by using electronic effects, such as reverb, as opposed to simply amplifying the sources unaltered.

<span class="mw-page-title-main">Horn loudspeaker</span> Loudspeaker using an acoustic horn

A horn loudspeaker is a loudspeaker or loudspeaker element which uses an acoustic horn to increase the overall efficiency of the driving element(s). A common form (right) consists of a compression driver which produces sound waves with a small metal diaphragm vibrated by an electromagnet, attached to a horn, a flaring duct to conduct the sound waves to the open air. Another type is a woofer driver mounted in a loudspeaker enclosure which is divided by internal partitions to form a zigzag flaring duct which functions as a horn; this type is called a folded horn speaker. The horn serves to improve the coupling efficiency between the speaker driver and the air. The horn can be thought of as an "acoustic transformer" that provides impedance matching between the relatively dense diaphragm material and the less-dense air. The result is greater acoustic output power from a given driver.

<span class="mw-page-title-main">JBL</span> American audio hardware manufacturer

JBL is an American audio equipment manufacturer headquartered in Los Angeles, California, United States. JBL serves the customer home and professional market. The professional market includes studios, installed/tour/portable sound, music production, DJ, cinema markets. The home market includes high-end home amplification/speakers/headphones as well as high-end car audio. JBL is owned by Harman International, itself a subsidiary of Samsung Electronics.

Altec Lansing, Inc. is an American audio electronics company founded in 1927. Their primary products are loudspeakers and associated audio electronics for professional, home, automotive and multimedia applications.

Henry Kloss was a prominent American audio engineer and entrepreneur who helped advance high fidelity loudspeaker and radio receiver technology beginning in the 1950s. Kloss was an undergraduate student in physics at the Massachusetts Institute of Technology, but never received a degree. He was responsible for a number of innovations, including, in part, the acoustic suspension loudspeaker and the high fidelity cassette deck. In 2000, Kloss was one of the first inductees into the Consumer Electronics Association's Hall of Fame. He earned an Emmy Award for his development of a projection television system, the Advent VideoBeam 1000.

Electro-Voice (EV) is an American manufacturer of audio equipment, including microphones, amplifiers, and loudspeakers, focused on pro audio applications such as sound reinforcement. As a subdivision of Bosch Communications Systems Inc. since 2006, Electro-Voice markets products for use by consumers as well as small or large concert venues, broadcasting, houses of worship, and in retail situations.

<span class="mw-page-title-main">Studio monitor</span> Speaker designed to reproduce sound accurately

Studio monitors are loudspeakers in speaker enclosures specifically designed for professional audio production applications, such as recording studios, filmmaking, television studios, radio studios and project or home studios, where accurate audio reproduction is crucial. Among audio engineers, the term monitor implies that the speaker is designed to produce relatively flat (linear) phase and frequency responses. In other words, it exhibits minimal emphasis or de-emphasis of particular frequencies, the loudspeaker gives an accurate reproduction of the tonal qualities of the source audio, and there will be no relative phase shift of particular frequencies—meaning no distortion in sound-stage perspective for stereo recordings. Beyond stereo sound-stage requirements, a linear phase response helps impulse response remain true to source without encountering "smearing". An unqualified reference to a monitor often refers to a near-field design. This is a speaker small enough to sit on a stand or desk in proximity to the listener, so that most of the sound that the listener hears is coming directly from the speaker, rather than reflecting off walls and ceilings. Monitor speakers may include more than one type of driver or, for monitoring low-frequency sounds, such as bass drum, additional subwoofer cabinets may be used.

<span class="mw-page-title-main">Meyer Sound Laboratories</span> American audio equipment manufacturer

Meyer Sound Laboratories is an American company based in Berkeley, California that manufactures self-powered loudspeakers, multichannel audio show control systems, electroacoustic architecture, and audio analysis tools for the professional sound reinforcement, fixed installation, and sound recording industries.

<span class="mw-page-title-main">John Kenneth Hilliard</span> American engineer

John Kenneth Hilliard was an American acoustical and electrical engineer who pioneered a number of important loudspeaker concepts and designs. He helped develop the practical use of recording sound for film and won an Academy Award in 1935. He designed movie theater sound systems, and he worked on radar as well as submarine detection equipment during World War II. Hilliard collaborated with James B. "Jim" Lansing in creating the long-lived Altec Voice of the Theatre speaker system. Hilliard researched high-intensity acoustics, vibration, miniaturization and long-line communications for NASA and the Air Force. Near the end of his career, he standardized noise-control criteria for home construction in California, a pattern since applied to new homes throughout the U.S.

LARES is an electronic sound enhancement system that uses microprocessors to control multiple loudspeakers and microphones placed around a performance space for the purpose of providing active acoustic treatment. LARES was invented in Massachusetts in 1988, by Dr David Griesinger and Steve Barbar who were working at Lexicon, Inc. LARES was given its own company division in 1990, and LARES Associates was formed in 1995 as a separate corporation. Since then, hundreds of LARES systems have been used in concert halls, opera houses performance venues, and houses of worship from outdoor music festivals to permanent indoor symphony halls.

<span class="mw-page-title-main">Audio engineer</span> Engineer involved in the recording, reproduction, or reinforcement of sound

An audio engineer helps to produce a recording or a live performance, balancing and adjusting sound sources using equalization, dynamics processing and audio effects, mixing, reproduction, and reinforcement of sound. Audio engineers work on the "technical aspect of recording—the placing of microphones, pre-amp knobs, the setting of levels. The physical recording of any project is done by an engineer…"

A coaxial loudspeaker is a loudspeaker system in which the individual driver units radiate sound from the same point or axis. Two general types exist: one is a compact design using two or three speaker drivers, usually in car audio, and the other is a two-way high-power design for professional audio, also known as single-source or dual-concentric loudspeakers. The design is favored for its compactness and behavior as an audio point source.

<span class="mw-page-title-main">Altec Lansing Duplex</span> Line of loudspeakers

DUPLEX was the trade name given by Altec Lansing to its line of coaxial loudspeakers, beginning with the first model 601 in 1943. However, the name was most commonly associated with the subsequent model 604 which was a seminal loudspeaker that became a milestone in loudspeaker development. Well over a dozen different models carried the Duplex name over a near 50-year period. The vast majority consisted of a high frequency (HF) compression driver mounted to the back of a large diameter paper cone low frequency (LF) driver. However, there were also a few models with small diameter LF cones and direct radiator tweeters.

<span class="mw-page-title-main">David Gunness</span> American audio engineer

David W. Gunness is an American audio engineer, electrical engineer and inventor. He is known for his work on loudspeaker design, especially high-output professional horn loudspeakers for public address, studio, theater, nightclub, concert and touring uses.

<span class="mw-page-title-main">Phase plug</span>

In a loudspeaker, a phase plug, phasing plug or acoustical transformer is a mechanical interface between a speaker driver and the audience. The phase plug extends high frequency response because it guides waves outward toward the listener rather than allowing them to interact destructively near the driver.

Clair Global, or simply Clair, is a professional sound reinforcement and live touring production support company. It was founded by brothers Roy and Gene Clair, who went into business in 1966 after they were asked to bring their sound system on tour with Frankie Valli and the Four Seasons. It is believed they were the first professional sound company to tour with a band. The company formally incorporated in 1970 as Clair Bros. Audio Enterprises, Inc.

<span class="mw-page-title-main">Charlie Hughes (audio engineer)</span> American inventor and audio engineer (born 1965)

Charles Emory Hughes II is an American inventor and audio engineer. He is known for his work on loudspeaker design, and the measurement of professional audio sound systems. Hughes first worked for Peavey Electronics designing loudspeakers and horns where he was granted a patent for the Quadratic-Throat Waveguide horn used in concert loudspeakers. He worked for Altec Lansing for two years as chief engineer for the pro audio division and was granted two more patents. In 2021, Hughes was hired by Biamp as principal engineer.

References

  1. ↑ Fellowship of the Audio Engineering Society 1982
  2. ↑ Cliff Henricksen Kentucky Colonel
  3. ↑ Electronic Musician Hall of Fame July 2012
  4. ↑ Ocean Way Audio - Cliff Henricksen
  5. ↑ Cliff Henricksen L1 Inventor
  6. ↑ Clifford Henricksen at Community Professional Systems
  7. ↑ Cliff Henricksen L1 Inventor
  8. ↑ Clifford Henricksen the inventor of the Personalized Amplification System™ family of products – Bose.com Archived February 15, 2013, at archive.today
  9. ↑ US Patent 7,936,891 B2 (Bose L1 Model2 “articulated array”)
  10. ↑ US Patent 7,260,235 (Line electroacoustical transducing Bose L1 line array for live music)
  11. ↑ US Patent 7,319,767 (Line array electroacoustical transducing Overall mechanical arrangement of Bose L1 model 1)
  12. ↑ US Patent D249,509 (Acoustical transformer for coupling sound waves from the diaphragm to the throat of a horn-type loudspeaker )
  13. ↑ US Patent 3,991,286 (Heat dissipating device for loudspeaker voice coil)
  14. ↑ US Patent 4,050,541 (Acoustical transformer for horn-type loudspeaker Altec "Tangerine " phase plug)
  15. ↑ US Patent 4,187,926 (Loudspeaker horn Altec “Manta-Ray” diffraction-slot constant-directivity horn)
  16. ↑ US Patent 4,130,023 (Method and apparatus for testing and evaluating loudspeaker performance Auto-Q directivity measurement method)
  17. ↑ US Patent 4,811,403 (Ultralight loudspeaker enclosures US Sound/Bose Corporation lightweight loudspeaker systems construction method)
  18. ↑ "Loudspeakers Enclosures and Headphones", Handbook for Sound Engineers-The New Audio Cyclopedia, Howard W. Sams Co. 1987
  19. ↑ "Sound Reinforcement in the Year 2000" 6th International Audio Engineering Society (AES) Conference on Sound Reinforcement 1989
  20. ↑ Journal of the Audio Engineering Society Volume 35 Number 10 1987 October
  21. ↑ "Directivity Response of Single Direct-Radiator Loudspeakers in Enclosures" Altec Technical Letter 227
  22. ↑ "Phase Plug Modelling and Analysis: Circumferential Versus Radial Types" Presented at the 59th Convention of the AES,Hamburg, Germany, March 1978, AES preprint 1328(F5)
  23. ↑ "The Manta-Ray Horns" (co-authored with Mark Ureda), Journal of the Audio Engineering Society, vol 26 no. 9, September 1978
  24. ↑ "Auto Q: A New Directivity Measurement System" Presented at 60th AES Convention, May 1978, Los Angeles, AES preprint 1360(F6)
  25. ↑ "Ultimate Performance of Wide-Range High Frequency Compression Drivers" Journal of the Audio Engineering Society vol 24, No 8, October 1976
  26. ↑ "Engineering Justifications for Selected Portions of the AES Recommended Practice for Specification of Loudspeaker Components" Presented as the 72nd Convention, October 1982, Anaheim CA, AES reprint 32(G10)
  27. ↑ "A High-Efficiency One-Decade Midrange Loudspeaker" (co-author with Bruce Howze) Paper on the Community M4 driver-Presented at the 70th convention, New York , October 1981, AES preprint 1848(D8)
  28. ↑ Sound and Video Contractor, June 1986 “Low-frequency driver performance,” Archived January 27, 2013, at the Wayback Machine
  29. ↑ "Unearthing the Mysteries of the Leslie Cabinet" Recording Engineer/Producer, April 1981 Archived March 2, 2013, at the Wayback Machine
  30. ↑ "Designing a Conical Bass-Horn Control Room" Recording Engineer/Producer, March 1987 [ permanent dead link ]
  31. ↑ "No Sweat, No Music-A Player Laments the Spread of Computer Dependency" Keyboard Magazine, August 1985
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