David W. Gunness (born November 7, 1960) is an American
audio engineer
An audio engineer (also known as a sound engineer or recording engineer) helps to produce a recording or a live performance, balancing and adjusting sound sources using equalization, dynamics processing and audio effects, mixing, reproduction, ...
,
electrical engineer and
inventor
An invention is a unique or novel device, method, composition, idea or process. An invention may be an improvement upon a machine, product, or process for increasing efficiency or lowering cost. It may also be an entirely new concept. If an ...
. He is known for his work on
loudspeaker
A loudspeaker (commonly referred to as a speaker or speaker driver) 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 " ...
design, especially high-output
professional
A professional is a member of a profession or any person who works in a specified professional activity. The term also describes the standards of education and training that prepare members of the profession with the particular knowledge and skil ...
horn loudspeaker
A horn loudspeaker is a loudspeaker or loudspeaker element which uses an horn (acoustic), acoustic horn to increase the overall efficiency of the driving element(s). A common form ''(right)'' consists of a compression driver which produces sound w ...
s for
public address, studio, theater, nightclub, concert and touring uses.
Gunness worked with
Electro-Voice in Michigan for 11 years, filing three patents related to horn technology. He worked at
Eastern Acoustic Works
Eastern Acoustic Works (EAW) is an American manufacturer of mainly professional audio reinforcement tools, such as loudspeaker systems and processors.
From 1978-1988 it was located at 59 Fountain Street in Framingham, Massachusetts, and subsequent ...
(EAW) in Massachusetts for 12 years, filing three patents in the process of creating a wide variety of loudspeaker products. For EAW, Gunness developed "Gunness Focusing"—a system for decreasing temporal response distortion in loudspeakers, involving the processing of the
audio signal
An audio signal is a representation of sound, typically using either a changing level of electrical voltage for analog signals, or a series of binary numbers for digital signals. Audio signals have frequencies in the audio frequency range of r ...
before it reaches the loudspeaker drivers, applying a reverse image of the expected distortion to cancel out the loudspeaker's idiosyncrasies. Gunness co-founded
Fulcrum Acoustic in 2008: a loudspeaker company with the aim of designing loudspeakers based on
digital signal processing
Digital signal processing (DSP) is the use of digital processing, such as by computers or more specialized digital signal processors, to perform a wide variety of signal processing operations. The digital signals processed in this manner are ...
(DSP), innovative components and high quality construction.
Early life
Gunness was born November 7, 1960; he grew up in
Janesville, Wisconsin
Janesville is a city in Rock County, Wisconsin, United States. It is the county seat and largest city in the county. It is a principal municipality of the Janesville, Wisconsin, Metropolitan Statistical Area and is included in the Madison–Jan ...
, enjoying outdoor activities such as bicycling, camping, hunting and fishing. At
Joseph A. Craig High School
Joseph A. Craig High School is a public high school located in the city of Janesville, Wisconsin. Craig, a part of the School District of Janesville, has a student enrollment of approximately 1,800. Located on the east side of Janesville, it is n ...
he participated in gymnastics and played guitar.
Two of his sisters entered the
University of Wisconsin–Madison
A university () is an educational institution, institution of higher education, higher (or Tertiary education, tertiary) education and research which awards academic degrees in several Discipline (academia), academic disciplines. Universities ty ...
(UW-Madison), but Gunness chose
Purdue University
Purdue University is a public land-grant research university in West Lafayette, Indiana, and the flagship campus of the Purdue University system. The university was founded in 1869 after Lafayette businessman John Purdue donated land and money ...
in
Indiana
Indiana () is a U.S. state in the Midwestern United States. It is the 38th-largest by area and the 17th-most populous of the 50 States. Its capital and largest city is Indianapolis. Indiana was admitted to the United States as the 19th s ...
. After one year there, he returned to Wisconsin to enroll at UW-Madison as an
electrical engineering
Electrical engineering is an engineering discipline concerned with the study, design, and application of equipment, devices, and systems which use electricity, electronics, and electromagnetism. It emerged as an identifiable occupation in the l ...
major. During his college years he made extra money as a musician; singing and playing acoustic guitar.
For these gigs he fabricated his own
loudspeaker
A loudspeaker (commonly referred to as a speaker or speaker driver) 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 " ...
s, and he determined to continue in this field, shifting his studies to focus on
acoustics
Acoustics is a branch of physics that deals with the study of mechanical waves in gases, liquids, and solids including topics such as vibration, sound, ultrasound and infrasound. A scientist who works in the field of acoustics is an acoustician ...
and
electronics
The field of electronics is a branch of physics and electrical engineering that deals with the emission, behaviour and effects of electrons using electronic devices. Electronics uses active devices to control electron flow by amplification ...
. In June 1984, Gunness graduated UW-Madison with a degree in Electrical and Computer Engineering. He immediately accepted an engineering job in
Buchanan, Michigan
Buchanan is a city in Berrien County in the U.S. state of Michigan. The population was 4,456 at the 2010 census. The city is located at the southeast corner of Buchanan Township, about 5 miles (8 km) west of Niles.
History
The community ...
, and relocated there. On September 29, 1984, he married Kathryn A. Sessions, a nursing student who had finished one year ahead of him at UW-Madison.
[
]
Electro-Voice
Directly after graduating UW-Madison, Gunness obtained a research and development
Research and development (R&D or R+D), known in Europe as research and technological development (RTD), is the set of innovative activities undertaken by corporations or governments in developing new services or products, and improving existi ...
position in the engineering department at the Electro-Voice (EV) factory in Michigan. Under Chief Engineer Ray Newman, Gunness worked on loudspeaker design, combining traditional empirical R&D methodologies with the emerging capabilities of computer analysis.[ His first assignment was to help develop the Musicaster 100, an all-weather 2-way ]coaxial loudspeaker
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 ...
; an update of the classic 1959 Musicaster design.
In 1984, Gunness filed a patent for a better way to use a manifold to combine the outputs of multiple compression driver
A compression driver is a small specialized diaphragm loudspeaker which generates the sound in a horn loudspeaker. It is attached to an acoustic horn, a widening duct which serves to radiate the sound efficiently into the air. It works in a " ...
s for increased sound power level
Sound power or acoustic power is the rate at which sound energy is emitted, reflected, transmitted or received, per unit time. It is defined as "through a surface, the product of the sound pressure, and the component of the particle velocity, at ...
(SPL), using two to four flat reflecting surfaces in the throat of a horn to redirect sound waves for a more coherent summation. This low-distortion manifold design made it possible for EV to produce its first high-power concert and touring loudspeaker: the MT-4, with "MT" standing for "Manifold Technology". This was a 4-way system split between two enclosures
Enclosure or Inclosure is a term, used in English landownership, that refers to the appropriation of "waste" or "common land" enclosing it and by doing so depriving commoners of their rights of access and privilege. Agreements to enclose land ...
, with four speaker driver
An electrodynamic speaker driver, often called simply a speaker driver when the type is implicit, is an individual transducer that converts an electrical audio signal to sound waves. While the term is sometimes used interchangeably with the ...
s summed in each bandpass; a total of 16 drivers. The upper two bandpasses used the Gunness manifold design for compression drivers, each manifold formed of two zinc castings. The medium low frequencies were carried by four cone drivers summed using a larger embodiment of the Gunness manifold concept based on ray tracing and reflection.[ Hosted by fulcrum-acoustic.com] The MT-4 was a very heavy system at , but it put more power into a smaller package, and it was quicker to position and connect. The MT-4 proved popular, used on major tours and festivals such as the 1995 Monsters of Rock
Monsters of Rock was an annual hard rock and heavy metal music festival held in Castle Donington, England, from 1980 to 1996, taking place every year except 1989 and 1993. It later branched into other locations such as the Netherlands, Poland, ...
at Donington Park
Donington Park is a motorsport circuit located near Castle Donington in Leicestershire, England. The circuit business is now owned by Jonathan Palmer's MotorSport Vision organisation, and the surrounding Donington Park Estate, still owned b ...
in central England and the main stage of the 1996 Lollapalooza
Lollapalooza (Lolla) is an annual American four-day music festival held in Grant Park in Chicago. It originally started as a touring event in 1991 but several years later made Chicago the permanent location for the annual music festival. Musi ...
tour featuring Metallica
Metallica is an American heavy metal band. The band was formed in 1981 in Los Angeles by vocalist/guitarist James Hetfield and drummer Lars Ulrich, and has been based in San Francisco for most of its career. The band's fast tempos, instrume ...
and Soundgarden
Soundgarden was an American rock band formed in Seattle, Washington, in 1984 by singer and drummer Chris Cornell, lead guitarist Kim Thayil (both of whom are the only members to appear in every incarnation of the band), and bassist Hiro Yamamo ...
. Together, EV engineer David Carlson and Gunness presented a paper to the Audio Engineering Society
The Audio Engineering Society (AES) is a professional body for engineers, scientists, other individuals with an interest or involvement in the professional audio industry. The membership largely comprises engineers developing devices or products ...
(AES) in November 1986, describing the methods they used to sum four drivers in each bandpass.[
In 1986, Gunness developed the EV HP series of ]horn loudspeaker
A horn loudspeaker is a loudspeaker or loudspeaker element which uses an horn (acoustic), acoustic horn to increase the overall efficiency of the driving element(s). A common form ''(right)'' consists of a compression driver which produces sound w ...
s based on the constant directivity (CD) characteristics described by EV engineer Don Keele
D. Broadus Keele Jr., also known simply as Don Keele or D. B. Keele Jr., is an American audio engineer and inventor who has helped shape and influence the professional and consumer loudspeaker industries since the early seventies. He is one of the ...
in the mid-1970s. Gunness recognized that relatively large 2-inch (51 mm) horn throats, commonly used for greater SPL, produced an undesirable narrowing of the output pattern above 10 kHz. His patented design used two longitudinal ribs or vanes to form three "pseudo horns" within the horn flare.
In 1989, Gunness developed an asymmetric horn with an output pattern shaped to suit a typical small-to-mid-sized rectangular auditorium with people sitting near the enclosure hearing sound that was not too loud and others sitting farther away hearing sound that was loud enough. In both cases, the sound pattern was to minimize sound energy bouncing off of walls; reflections creating unwanted multi-path cancellations. The horn featured a vertical diffraction slot that was narrower at the bottom which reduced the output for people sitting below the enclosure in the nearfield, and increased the output for those sitting farther away. EV's sister company, Altec Lansing, marketed this product as the "Vari-Intense" horn.
Gunness researched automated methods for analyzing the performance of a loudspeaker. In 1990 he delivered a paper to the AES describing a system which used pink noise
Pink noise or noise is a signal or process with a frequency spectrum such that the power spectral density (power per frequency interval) is inversely proportional to the frequency of the signal. In pink noise, each octave interval (halving ...
and a filtered receiver to generate polar response curves plotting loudspeaker output patterns.
Eastern Acoustic Works
In September 1995, Gunness moved his family, now including a son and a daughter, from Michigan to Massachusetts in response to his taking a position as senior engineer at Eastern Acoustic Works
Eastern Acoustic Works (EAW) is an American manufacturer of mainly professional audio reinforcement tools, such as loudspeaker systems and processors.
From 1978-1988 it was located at 59 Fountain Street in Framingham, Massachusetts, and subsequent ...
(EAW) in Whitinsville
Whitinsville is an unincorporated village within the town of Northbridge in Worcester County, Massachusetts, United States. Whitinsville is a census-designated place (CDP) and its population was 6,750 at the 2020 census. Whitinsville is pronoun ...
.[ His first task was to set up a system for creating custom loudspeaker designs for specific clients and purposes, and he performed much field work, tuning and optimizing loudspeaker installations. He then began to research the concept of phased point source behavior with the goal of controlling the directional characteristics of a high-powered concert loudspeaker cluster.] This work led to the development of EAW's KF900 series concert touring system. In 1997 he filed two patents related to this research: one for a downfill loudspeaker that would direct sound downward without being rigged differently than its upper neighbors, and a method for creating a "common acoustical wavefront" of horizontally arrayed loudspeaker horns mounted in trapezoid enclosures which placed the acoustic center of the array very close to the rear of the enclosure. The horn mouths minimized diffraction between enclosures. The KF900 system incorporated digital signal processing
Digital signal processing (DSP) is the use of digital processing, such as by computers or more specialized digital signal processors, to perform a wide variety of signal processing operations. The digital signals processed in this manner are ...
(DSP) for each horizontal row of drivers in the loudspeaker cluster. Gunness said that bringing the DSP to fruition by way of rigorous mathematical performance analysis was a "massive undertaking" which gave him a broad foundation of computer analysis techniques he would draw from in later inventions.[ The KF900 was deployed in mid-1998 for 11 ]Promise Keepers
Promise Keepers is an Evangelical Christian parachurch organization for men. It originated in the United States, but independent branches have also been established in Canada and New Zealand.
Promise Keepers describes its goal as "to bring abo ...
tour dates, and its response was measured during the shows as part of an iterative product optimization plan. In 2001, Eric Clapton
Eric Patrick Clapton (born 1945) is an English rock and blues guitarist, singer, and songwriter. He is often regarded as one of the most successful and influential guitarists in rock music. Clapton ranked second in ''Rolling Stone''s list of ...
used the KF900 system while touring in support of his ''Reptile'' album. In his work to predict the performance of various KF900 loudspeaker configurations, Gunness used acoustical measurement and modeling software called FChart that he started developing while still at Electro-Voice.[ ]Heinz Field
Acrisure Stadium is a football stadium located in the North Shore neighborhood of Pittsburgh, Pennsylvania, United States. It primarily serves as the home of the Pittsburgh Steelers of the National Football League (NFL) and the Pittsburgh Panth ...
, home of the Pittsburgh Steelers
The Pittsburgh Steelers are a professional American football team based in Pittsburgh. The Steelers compete in the National Football League (NFL) as a member club of the American Football Conference (AFC) North division. Founded in , the Steel ...
football team received an installed KF900 system, as did Fenway Park
Fenway Park is a baseball stadium located in Boston, Massachusetts, United States, near Kenmore Square. Since 1912, it has been the home of the Boston Red Sox, the city's American League baseball team, and since 1953, its only Major League Base ...
, home of the Boston Red Sox
The Boston Red Sox are an American professional baseball team based in Boston. The Red Sox compete in Major League Baseball (MLB) as a member club of the American League (AL) East division. Founded in as one of the American League's eight ...
baseball team. The final system tuning at Fenway was performed using Smaart
Smaart (System Measurement Acoustical Analysis in Real Time) is a suite of audio and acoustical measurements and instrumentation software tools introduced in 1996 by JBL's professional audio division. It is designed to help the live sound engin ...
software.
Gunness also designed the following EAW loudspeaker models: the long-throw MH433 trapezoid with rigging points, the install-only BH822 twin 12-inch "super" subwoofer
A subwoofer (or sub) is a loudspeaker designed to reproduce low-pitched audio frequencies known as bass and sub-bass, lower in frequency than those which can be (optimally) generated by a woofer. The typical frequency range for a subwoofer i ...
, the LA400 touring subwoofer, and the large format arrayable MQ series.
Gunness Focusing
For years, Gunness had been looking for various electronic solutions to the undesirable characteristics of horns. At EV in 1985, Gunness noticed the performance differences between various shapes of horns, and theorized that an electronic filter might allow optimization. In early 1995, EV gained access to Altec Lansing's 1987 Acousta-CADD acoustic modeling software which revealed more loudspeaker performance characteristics than had previously been observed, but DSP programming tools were still inadequate for audio signal correction. In 2000, Greek electroacousticians John Mourjopoulos and Panagiotis 'Panos' Hatziantoniou described a method for smoothing precise audio analysis filters. Building on this work, Gunness led a team of EAW engineers to develop a proprietary wavelet transform spectrogram
A spectrogram is a visual representation of the spectrum of frequencies of a signal as it varies with time.
When applied to an audio signal, spectrograms are sometimes called sonographs, voiceprints, or voicegrams. When the data are represen ...
for internal research. The EAW spectrogram reduced visual complexity by applying a zero-phase-shift low-pass filter
A low-pass filter is a filter that passes signals with a frequency lower than a selected cutoff frequency and attenuates signals with frequencies higher than the cutoff frequency. The exact frequency response of the filter depends on the filter des ...
to the audio signal under test using mirror-image infinite impulse response
Infinite impulse response (IIR) is a property applying to many linear time-invariant systems that are distinguished by having an impulse response h(t) which does not become exactly zero past a certain point, but continues indefinitely. This is in ...
(IIR) filters.[ Hosted by EAW.com] The spectrogram revealed loudspeaker performance anomalies, allowing the engineering team to identify mechanisms they characterized as "two-port systems"; i.e. mechanisms demonstrating a single input, a single transfer function
In engineering, a transfer function (also known as system function or network function) of a system, sub-system, or component is a function (mathematics), mathematical function that mathematical model, theoretically models the system's output for ...
, and a single output. Such two-port systems were of interest because they could possibly be corrected with electronic filtering. Because of their variability the methodology would not be used on any of the mechanisms which appeared to be non-linear relative to signal level, spatial distribution ("coverage"), or over time, such as cone stiffness or surround compliance. This left several substantial "linear, time-invariant" (LTI) mechanisms that would yield to correction by digital filter
In signal processing, a digital filter is a system that performs mathematical operations on a sampled, discrete-time signal to reduce or enhance certain aspects of that signal. This is in contrast to the other major type of electronic filter, t ...
ing. These included 1) time-smear from the compression driver/phase plug
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 th ...
interface, 2) horn resonance, 3) cone resonance, and 4) crossover phase linearity between adjacent bandpasses. In April 2005, EAW announced the NT Series, a line of 2-way bi-amplified self-powered loudspeakers incorporating the "new technology" which was initially called "Digital Transduction Correction" (DTC). ''Mix'' magazine quoted Gunness identifying compression driver "time smear" as a longstanding loudspeaker problem that was countered by preconditioning in the audio signal.[ Later that year, EAW dropped the DTC acronym and began promoting the technology as "Gunness Focusing".]
At the AES convention in October 2005 in New York City, EAW project engineer William "Bill" Hoy and Gunness presented a paper describing the mathematics of the spectrogram.[ Hosted by fulcrum-acoustic.com] At the same convention, Gunness spoke about the research and development which culminated in the new technology. He described how the spectrogram allowed the EAW engineering team to observe the mechanism of time smear occurring in the small space between the compression driver diaphragm and the phase plug. He discovered that only half of the compression driver's energy, at best, goes directly from the diaphragm through a phase plug slot or port and into the horn throat. The rest of the sound waves either reflect back to the compression driver surface or travel to another phase plug slot or port; in both cases the result is wave energy leaving the phase plug after the initial impulse. Gunness modeled this behavior mathematically and applied an inverted signal to cancel out the later wave energy. Gunness filed a patent for the technology in March 2006. Later that year, EAW introduced the UX8800, a DSP-based loudspeaker management system with four inputs and eight outputs. The UX8800 was offered to allow Gunness Focusing to be applied to selected pre-existing EAW products such as the KF700 line array series. Gunness Focusing was nominated for but did not win a TEC Award The TEC Awards is an annual program recognizing the achievements of audio professionals. The awards are given to honor technically innovative products as well as companies and individuals who have excelled in sound for television, film, recordings, ...
in 2006.
Line arrays
Gunness joined with EAW co-founder Kenton Forsythe and engineer Jeff Rocha to design the KF760 and KF730 series line array systems. The KF760 was a full-size 3-way system and the KF730 was a compact 3-way system. Either system could be augmented with ground-stacked or flown subwoofers. Common to the two different sizes of KF700 series products was the principal of "divergence shading" rather than the more usual intensity shading. The vertical output pattern of the individual line array elements was adjusted to optimize SPL received by near- and far-field audience areas. This method avoided what Gunness said was a discontinuity between adjacent loudspeaker enclosures driven at different signal levels; he observed smeared transients and frequency response problems. Gunness wrote about divergence shading and general line array issues in August 2000. The KF760 product was revealed in May 2001. The major concerts using the KF760s included ''The Boston Globe
''The Boston Globe'' is an American daily newspaper founded and based in Boston, Massachusetts. The newspaper has won a total of 27 Pulitzer Prizes, and has a total circulation of close to 300,000 print and digital subscribers. ''The Boston Glob ...
''s Jazz and Blues Festival in 2001, Usher's 2002 ''Evolution'' tour, Pearl Jam
Pearl Jam is an American rock band formed in Seattle, Washington, in 1990. The band's lineup consists of founding members Jeff Ament (bass guitar), Stone Gossard (rhythm guitar), Mike McCready (lead guitar), and Eddie Vedder (lead vocals, guita ...
's 2003 Riot Act Tour
The Riot Act Tour was a concert tour by the American rock band Pearl Jam to support its seventh album, ''Riot Act''.
History
Pearl Jam promoted ''Riot Act'' with tours in Australia, Japan, and North America in 2003. The tours were the band's fi ...
, the North American dates of Iron Maiden
Iron Maiden are an English heavy metal band formed in Leyton, East London, in 1975 by bassist and primary songwriter Steve Harris. While fluid in the early years of the band, the lineup for most of the band's history has consisted of Harri ...
's 2003 Give Me Ed... 'Til I'm Dead Tour, and Sir Paul McCartney
Sir James Paul McCartney (born 18 June 1942) is an English singer, songwriter and musician who gained worldwide fame with the Beatles, for whom he played bass guitar and shared primary songwriting and lead vocal duties with John Lennon. One ...
playing in Moscow's Red Square in 2003. Usher also used flown KF761 boxes for his vocal stage monitoring system; monitor engineer Maceo Price and sound company owner Tim Cain sat down with Gunness and Rocha, looking at prediction software results to determine which EAW product line would best suit the purpose of loud monitors that would not be in the way of Usher's dancing and set changes. By late 2006, the KF760 and KF730 line array products had been augmented with optional Gunness Focusing by way of the UX8800 loudspeaker management system. THC Audio in Sofia
Sofia ( ; bg, София, Sofiya, ) is the capital and largest city of Bulgaria. It is situated in the Sofia Valley at the foot of the Vitosha mountain in the western parts of the country. The city is built west of the Iskar river, and ha ...
used the UX8800/KF760 combination for Snoop Dogg
Calvin Cordozar Broadus Jr. (born October 20, 1971), known professionally as Snoop Dogg (previously Snoop Doggy Dogg and briefly Snoop Lion), is an American rapper. His fame dates back to 1992 when he featured on Dr. Dre's debut solo single, " ...
's Bulgarian performance in 2008.
Gunness appeared as a panelist at an AES line array tutorial and workshop in October 2002, held in Los Angeles. Don Keele, whose 1970s CD horn discoveries formed a basis for Gunness's later research, shared the panel. In October 2003, Gunness wrote an article about "Digitally Steerable Array" (DSA) technology for ''Live Sound International'' magazine. He expanded on the DSA concept the next month for the British Institute of Acoustics (IOA). DSA allowed for adjustments to the vertical output width and vertical direction of a column of mid- to high-frequency loudspeaker drivers, in a frequency range from about 500 Hz to 16 kHz; a range critical to voice intelligibility. Gunness wrote that his research into DSA began in the 1990s and was largely based on the observations gained in developing the KF900 series. The proprietary FChart software was leveraged to create "DSA Pilot" to supply prediction and adjustment software for DSA installations. DSA Pilot allowed the installer to change the vertical pattern of a DSA product from 15 to 120 degrees high, and to change the main direction up or down by 30 degrees, without changing the position of the enclosure. Gunness told the IOA that each transducer in the vertical column must have its own DSP and amplifier for proper steering of the output pattern. For high frequency control, physically small drivers are required. One of the benefits of DSA was that the loudspeaker enclosure could be mounted flat against a vertical wall rather than tilted. The flat position eliminated the problem of acoustic energy radiating from the back of the enclosure, smearing the forward output with multi-path arrival times.[
In February 2000, Mackie Designs bought EAW but retained the EAW brand. In 2003, Mackie Designs changed its name to ]LOUD Technologies
LOUD Audio, LLC is a professional audio company based in the United States, operating in the U.S., Canada, and Shenzhen, China. Originally founded as Mackie Designs, Inc., the name was changed to Loud Technologies Inc in 2003 to differentiate its ...
and moved previously Seattle-based Mackie
Mackie is an American professional audio products brand. Founded in Seattle in 1988 by Greg Mackie as a manufacturer of affordable and versatile compact pro audio mixers, Mackie is the primary product line of LOUD Technologies.
History
Mackie ...
manufacturing to Asia. In late 2006, LOUD moved EAW's loudspeaker production to China; the Massachusetts factory which had employed 100 assembly and woodshop workers was greatly reduced. EAW's plant retained the ability to fill some custom loudspeaker orders, they kept a number of management and clerical positions, and also the design team of Kenton Forsythe, David Gunness and Jeff Rocha. Gunness continued to research and prototype loudspeakers, and he checked Chinese production examples for quality of workmanship. In January 2007, EAW co-founder Kenneth Berger, a senior vice president of LOUD, left the company.
Fulcrum Acoustic
Gunness left EAW in January 2008 to join with partners Stephen Siegel and Chris Alfiero in the establishment of Fulcrum Acoustic, a loudspeaker design and manufacturing company. Gunness became Vice President of R&D, and Lead Product Designer.[ The goal of Fulcrum Acoustic was to produce loudspeakers with "advanced DSP algorithms as integral to their designs" which had become Gunness's signature style. Gunness soon noticed that the time from initial concept to product launch was much faster at a small company.][ Most of the employees of Fulcrum Acoustic are former EAW coworkers.
]
Temporal Equalization
Gunness and Siegel turned their attention to coaxial loudspeaker
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 ...
s, known for their desired single-point-source characteristics but also for various problems associated with intermodulation
Intermodulation (IM) or intermodulation distortion (IMD) is the amplitude modulation of signals containing two or more different frequencies, caused by nonlinearities or time variance in a system. The intermodulation between frequency comp ...
distortion—the low frequencies modulating the highs—and undesirable sonic variations in off-axis frequency response. Other negative aspects of traditional coaxial designs were their bulky weight and their lengthy axis requiring deep enclosures. Gunness and Siegel set about designing a coaxial with a common magnet for both low and high frequency drivers for weight savings and for reduced axial length, and a horn was developed to direct as much high frequency energy as possible away from the low frequency cone. A DSP solution called "Temporal Equalization" (TQ) was used to cancel out any remaining high frequency energy arriving at the moving cone. TQ was also used to cancel out high frequency horn reflections that returned to the compression driver. Gunness further developed his proprietary FChart software, renamed "Rayliegh" in honor of Lord Rayleigh
John William Strutt, 3rd Baron Rayleigh, (; 12 November 1842 – 30 June 1919) was an English mathematician and physicist who made extensive contributions to science. He spent all of his academic career at the University of Cambridge. Am ...
, to enhance its capabilities for developing these and future products.
Gunness helped specify and design a 16-zone, 100-loudspeaker installation at the Haze nightclub at Aria Resort and Casino
Aria Resort and Casino is a luxury resort and casino, part of the CityCenter complex on the Las Vegas Strip in Paradise, Nevada. Aria consists of two curved glass and steel highrise towers adjoined at the center. It opened on December 16, 2009 a ...
in Las Vegas, and he joined with Jamie Anderson of Rational Acoustics to discuss the loudspeaker performance targets and system tuning process via Smaart software, the talk given at a technical tour held in June 2010 during the Infocomm convention. Gunness said that system designer John Lyons asked for a subwoofer that would "crush" at all locations on the dance floor. Gunness responded by creating the US221 subwoofer with two drivers. After hearing Haze's 130 dB SPL results, with a reported 10 dB of extra headroom because ten US221s were used, Lyons quipped that the system surpassed "crush" to establish "punish" as a benchmark. The same month, the Surrender nightclub at Encore Las Vegas
Encore Las Vegas (also called Encore at Wynn Las Vegas or simply Encore) is a luxury resort, casino and hotel located on the Las Vegas Strip in Paradise, Nevada. The resort is connected to its sister resort, Wynn Las Vegas, located directly sout ...
opened with a Fulcrum Acoustic installation combining outdoor and indoor areas. Gunness aided in setting up and tuning the system. He noted that three US221 subwoofers supplied sufficiently high energy sound for the small dance floor. In December 2012, ''Wired
''Wired'' (stylized as ''WIRED'') is a monthly American magazine, published in print and online editions, that focuses on how emerging technologies affect culture, the economy, and politics. Owned by Condé Nast, it is headquartered in San Fra ...
'' magazine wrote about how temporal corrections developed by Gunness cleaned up "the smear of sound" present in normal nightclub loudspeakers.
References
External links
List of white papers
at Fulcrum Acoustic
*
{{DEFAULTSORT:Gunness, Dave
1960 births
American audio engineers
American electrical engineers
Living people
People from Buchanan, Michigan
People from Janesville, Wisconsin
People from Worcester, Massachusetts
American sound designers
University of Wisconsin–Madison College of Engineering alumni
21st-century American inventors
Joseph A. Craig High School alumni