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The Hartsfield has to be credited with establishing JBL's
reputation as builders of the finest loudspeaker available. This is not
hyperbole. In a 1955 article on the hi-fi industry, Life magazine called the
Hartsfield "the ultimate dream speaker". High Fidelity magazine stated in
another 1955 article, "of all of the Klipsch derived family, one speaker, in
my estimation, is noticeably superior - the Lansing Hartsfield."
Klipschorn Cross-Section
© Klipsch Audio Technologies
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The development of the Hartsfield was intrinsically tied to the success of
the previously introduced Klipschorn. Paul Klipsch had developed his
namesake speaker in 1949. It was an ingenious design that used a complex
folded horn to front load a 15" bass driver and then used a corner placement
that allowed the walls of a room to act as an extension of the horn. This
increased the effective horn length to allow bass extension to 35hz.
That speaker was a stunning success due to its combination of unparalleled
efficiency and full bandwidth response. Almost every home speaker
manufacturer rushed to develop a version of the corner horn. JBL was not
immune to this pressure. JBL's dealers were clamoring for a product to
compete in this market. Enter William L. Hartsfield.
Bill Hartsfield was an employee of the U.S. Bureau of Standards in
Washington D.C. He had belonged to the same chapter of the AES as Ray Pepe,
JBL's Vice President of Marketing when Pepe had lived on the eastern
seaboard. Ray was aware of Hartsfield's work in building his own home
variant of the Klipschorn as a personal avocation. It was a natural fit that
Bill Hartsfield would be called upon to develop JBL's version of a corner
horn. He was hired on retainer as a consultant to JBL to develop a corner
horn speaker.
The design of the Hartsfield was not terribly innovative. Instead, it was an
example of refining a proven concept with an uncompromised approach to
design and build quality. (Nonetheless, the Hartsfield design was considered
unique enough that a patent was issued in 1957) While there had been some
criticism of the Klipschorn in its use of mass market drive units and an
insufficiently rigid cabinet, there would be no such compromises with the
Hartsfield.
Patent for the Original
Design of the Hartsfield
Courtesy David Gamlowski
Hartsfield 085 Component Kit
© Stereo Sound Japan, Courtesy
Koji Onedera
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The Hartsfield would incorporate the highest quality drivers in JBL's
inventory - the 085 kit consisting of the 150-4C bass driver and the 375
high frequency compression driver. Both units had been originally designed
for professional use in theatre speakers. The 150-4C used the same magnet
and basket as the earlier D130 and 130A but added an extension to the outer
rim. This allowed the installation of a steep-angled, straight-sided cone
compared to the curvilinear cone in the earlier units. This cone design
provided added strength to accommodate horn loading of the driver.
The 375 had just been introduced and was developing a reputation as the
finest high frequency driver available. It was unique in its use of a 4"
diaphragm and 2" throat exit. The 4" diaphragm and voice coil allowed for
unparalleled output and the large throat resulted in minimal distortion.
This driver was combined with a brand new H-5039 exponential horn and
"Koustical Lens" developed by Bart Locanthi. It was crossed over at 500hz
using the N-500 dividing network.
The cabinet for the Hartsfield used inordinately heavy stock for its
construction. It was comprehensively braced to result in an extremely solid
and rigid enclosure. A single speaker weighed over 250 pounds. The final
system was a sonic and visual powerhouse.
The Hartsfield was introduced in 1954 to near universal acclaim that reached
a pinnacle with the publication of the previously mentioned Life magazine
article. The publicity generated by that article resulted in an immediate
jump in name recognition and sales for JBL. JBL's Los Angeles location, in
the center of the movie and recording industry, resulted in the sale of a
number of Hartsfield systems to local celebrities. This fact was played up
in subsequent marketing campaigns to great success.
Hartsfield
D208 Installation
© Harman International, Courtesy Mark
Gander and John Eargle
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A little known fact about the Hartsfield was that it was possible to
purchase a "starter" system in the early years that could later be upgraded
to the full D30085 system. That system used a single 8" D208 speaker
operating in full range. The speaker was mounted immediately behind the
"Koustical Lens" and used a duct to back load the driver into the bass horn.
The logic of stuffing a $25 driver into a $300 enclosure was questionable at
best and was never a marketing success. This option was dropped within two
years.
In 1959, there was a significant redesign of the bass horn in the
Hartsfield. The stated purpose was to simplify the horn path to result in a
smoother response. However, it was likely that the greater motivation was
monetary since the redesign resulted in a simplified construction that
significantly reduced manufacturing costs.
Original Hartsfield Horn Path
© Stereo Sound Japan, Courtesy
Koji Onedera
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In 1964, the driver configuration was changed to add the 075 ring radiator
to make a three-way system. This addressed a long standing limitation of the
Hartsfield -- a restricted high frequency bandwidth. The 375 driver never
did extend much beyond 10Khz. In the 1950's, this was not that significant
since most recordings were also restricted in high end response. However, by
the 1960's it was common for recordings to contain information that reached
into the highest octaves. The new 085 configuration, consisting of the
150-4C bass driver, 375 midrange, 537-509 horn, 075 tweeter, N400(or N500H)
and N7000 cross-overs, could now boast a bandwidth that would extend beyond
the limits of human hearing.
Unfortunately, 1964 was also the last year of production for the Hartsfield.
Its discontinuance was related to the success of stereo reproduction. The
requirement for a corner placement was not a significant issue when only one
speaker had to be located in a monaural system. However, a stereo system
required two, unobstructed, adjacent corners that were reasonably spaced.
Not every home could accommodate this requirement and thus the available
market was restricted.
Nonetheless, the success and impact of the Hartsfield to JBL cannot be
overstated. According to Margaret Thomas, the wife of Bill Thomas and a long
time JBL employee, the Hartsfield "made" JBL. It was that speaker that gave
the company national recognition. It was in large part responsible for sales
increases that would average over 50% a year for the next three years.
© 2000 Don McRitchie
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