Page7
Monolith III User's Manual
extremely accurate speaker, but
Janszen found that the cone speakers
of the period were too nonlinear in
phase and amplitude response to meet
his criteria. Janszen believed that
electrostats were inherently more linear
than cones, so he built a model using a
thin plastic diaphragm treated with a
conductive coating. This model
confirmed Janszen's beliefs, for it
exhibited remarkable phase and
amplitude linearity.
Janszen was so excited with the results
that he continued research on the
electrostatic speaker on his own time.
He soon thought of insulating the
stators to prevent the destructive effects
of arcing. By 1952 he had an electro-
static tweeter element ready for
commercial production. This new
tweeter soon created a sensation
among American audio hobbyists.
Since Janszen's tweeter element was
limited to high frequency reproduction, it
often found itself used in conjunction
with woofers, most notably, woofers
from Acoustic Research. These
systems were highly regarded by all
audio enthusiasts.
As good as these systems were, they
would soon be surpassed by another
electrostatic speaker.
In 1955, Peter Walker published three
articles on electrostatic loudspeaker
design in
Wireless World, a British
electronics magazine. In these articles
Walker demonstrated the benefits of the
electrostatic loudspeaker. He explained
that electrostatics permit the use of
diaphragms that are low in mass, large
in area, and uniformly driven over their
surfaces by electrostatic forces. Due to
these characteristics, electrostats have
the inherent ability to produce a wide
bandwidth, flat frequency response with
distortion products being no greater
than the electronics driving them.
By 1956 Walker backed up his articles
by introducing a consumer product, the
now famous Quad ESL. This speaker
immediately set a standard of perform-
ance for the audio industry due to its
incredible accuracy. However, in actual
use the Quad had a few problems. It
could not play very loud, it had poor
bass performance, it presented a
difficult load that some amplifiers did
not like, its dispersion was very
directional, and its power handling was
limited to around 70 watts. As a result,
many people continued to use box
speakers with cones.
In the early 1960's Arthur Janszen
joined forces with the KLH loudspeaker
company and together they introduced
the KLH 9. Due to the large size of the
KLH 9, it did not have as many limita-
tions as the Quad. The KLH 9 could
play markedly louder and lower in
frequency than the Quad ESL. Thus a
rivalry was born.
Janszen continued to develop electro-
static designs. He was instrumental in
the design of the Koss Model One, the
Acoustech, and the Dennesen speak-
ers. Roger West, the chief designer of
the JansZen Corporation became the
president of Sound Lab. When JansZen
Corporation was sold, the RTR
loudspeaker company bought half of
the production tooling. This tooling was
used to make the electrostatic panels
for the Servostatic, a hybrid electrostatic
system that was Infinity's first speaker
product. Other companies soon
followed; each with their own unique
applications of the technology. These
include Acoustat, Audiostatic, Beverage,
Dayton Wright, Sound Lab, and Stax to
name a few.
Electrostatic speakers have pro-
gressed and prospered because they
actually do what Peter Walker claimed
they would. The limitations and prob-
lems experienced in the past were not
inherent to the electrostatic concept.
They were related to the applications of
these concepts.
Today, these limitations have been
addressed. Advancements in materials
due to the U.S. space program give
designers the ability to harness the
superiority of the electrostatic principle.
Todays electrostats use advanced
insulation techniques or provide
protection circuitry. The poor dispersion
properties of early models have been
addressed by using delay lines,
acoustical lenses, multiple panel arrays
or, as in our own products, by curving
the diaphragm. Power handling and
sensitivity have been increased.
These developments allow the con-
sumer the opportunity to own the
highest performance loudspeaker
products ever built. It's too bad Rice and
Kellogg were never able to see just how
far the technology would be taken.
