11
In the late 1800’s, any loudspeaker was considered
exotic. Today, most of us take the wonders of sound
reproduction for granted.
It was 1880 before Thomas Edison had invented
the first phonograph. This was a horn-loaded
diaphragm that was excited by a playback
stylus. In 1898, Sir Oliver Lodge invented a
cone loudspeaker, which he referred to as a
“bellowing telephone”, that was very similar to
the conventional cone loudspeaker drivers that we
know today. However, Lodge had no intention for
his device to reproduce music because in 1898
there was no way to amplify an electrical signal!
As a result, his speaker had nothing to offer over
the acoustical gramophones of the period. It was
not until 1906 that Dr. Lee DeForrest invented the
triode vacuum tube. Before this, an electrical signal
could not be amplified. The loudspeaker, as we
know it today, should have ensued then, but it did
not. Amazingly, it was almost twenty years before
this would occur.
In 1921, the electrically cut phonograph record
became a reality. This method of recording was
far superior to the mechanically cut record and
possessed almost 30 dB of dynamic range.
The acoustical gramophone couldn’t begin to
reproduce all of the information on this new disc.
As a result, further developments in loudspeakers
were needed to cope with this amazing new
recording medium.
By 1923, the decision to develop a complete
musical playback system consisting of an electronic
phonograph and a loudspeaker to take advantage
of the new recording medium – the project of two
young engineers, C. W. Rice and E. W. Kellogg.
Rice and Kellogg had a well equipped laboratory
at their disposal. This lab possessed a vacuum
tube amplifier with an unheard of 200 watts,
a large selection of the new electrically cut
phonograph records and a variety of loudspeaker
prototypes collecting over the past decade.
Among these were Lodge’s cone, a speaker that
used compressed air, a corona discharge (plasma)
speaker, and an electrostatic speaker.
After a short time, Rice and Kellogg had narrowed
the field of “contestants” down to the cone
and the electrostat. The outcome would dictate
the way that future generations would refer to
loudspeakers as being either “conventional”
or “exotic”.
Rice and Kellogg’s electrostat was something
to behold. This enormous bipolar speaker was
as big as a door. The diaphragm, which was
beginning to rot, was made of a pig intestine that
was covered with fine gold leaf to conduct the
audio signal.
When Rice and Kellogg began playing the new
electrically cut records through the electrostat,
they were stunned and impressed. The electrostat
e
lectrostatIc
H
Istory
FOLDED MOTION™ TWEETER
The Folded Motion Tweeter works by moving air
(which creates sound) perpendicular to the folded
ridges of the diaphragm, similar to how an accor-
dion works. This extremely low mass diaphragm
“squeezes” air and requires almost 90% less
excursion than the typical 1” dome tweeter, which
drastically minimizes distortion while providing a
lightning fast response time. The increased surface
area also provides a wide, yet controlled sound
dispersion to create a realistic and carefully etched
sound stage.
Содержание EM-ESL C
Страница 1: ...u s e r s m a n u a l...
Страница 21: ...g u i d e d e l u t i l i s a t e u r...
