Full Range Operation - MartinLogan Classic ESL 9 User Manual

Full Range Operation

Another significant advantage of MartinLogan's exclusive trans-
ducer technology reveals itself when you look at examples of
other loudspeaker products on the market today. MartinLogan
electrostats uses no crossover networks in critical frequency
ranges because they are not needed. The single, seamless
electrostatic membrane reproduces all frequencies above the
single crossover point. How is this possible?
First we must understand that music is not composed of separate
high, mid and low frequencies. In fact, music is comprised of a
single waveform with all frequencies interacting simultaneously.
The electrostatic transducer of the speaker essentially acts as
an exact opposite of the microphones used to record the origi-
nal event. A microphone, which is a single working element,
transforms acoustic energy into an electrical signal that can be
amplified or preserved by some type of storage media. The
speaker's electrostatic transducer transforms electrical energy
from your amplifier back into acoustical energy.
Due to the limitations of electromagnetic drivers, no single
unit can reproduce the full range of frequencies. Instead, these
MartinLogan Classic ESL 9
ESL
Panel
crossover point (400 Hz)
This diagram illustrates how a conventional speaker
Woofer
system must use multiple crossover networks that
have negative effects on the musical performance.
drivers must be designed to operate within a narrow, fixed
bandwidth of the frequency range, and then combined electri-
cally so that the sum of the parts equals the total signal. While
nice in theory, we must deal with real-world conditions.
In order to use multiple drivers, a crossover network is enlist-
ed to attempt a division of the complex musical signal into
the separate pieces (usually highs, mids, and lows) that each
specific driver was designed to handle. Unfortunately, due
to the phase relationships that occur within all crossover net-
works and during the acoustical recombination process,
nonlinearities and severe degradation of the music signal take
place in the ear's most critical zone.
The speaker's electrostatic transducer can single-handedly
reproduce all frequencies above the crossover point simulta-
neously. You have in one transducer the ability to handle in
elegant simplicity the critical frequencies.
The crossover phase aberrations that are associated with tradi-
tional tweeter, midrange, and woofer systems are eliminated.
The result is a dramatic improvement in imaging and staging
performance due to the minutely accurate phase relationship
of the full-range panel wave launch.
Conventional Loudspeaker
crossover point (2,000–5,000 Hz)
Critical Zone
crossover point (100–400 Hz)
Tweeter
Midrange
Woofer
13