MartinLogan PASSAGE TM - Manual (Page 11)

ATF Operation
The MartinLogan ATF transducer (based on RADIA planar
technology) consists of a micro-thin, low-mass Kaladex
diaphragm with an ultra-light, etched conductive alumi-
num surface suspended between two high field strength
neodymium super magnet arrays (see figure 17). When an
electrical current (music signal) passes through the etched
aluminum on the diaphragm's surface it is simultaneously
pulled towards one of the neodymium arrays and pushed
away from the opposing array. When the direction of current
is reversed the diaphragm is simultaneously pushed and
pulled in the opposite direction, thus producing sound.
Extremely Low-Mass Diaphragm
—Blazing Speed and Inner Detail
Low-mass diaphragms are crucial to a loudspeaker's ability
to accurately reproduce sound. As the mass of a transducer's
diaphragm decreases, its ability to resolve detail increases.
With extremely low-mass characteristics, the ATF transducer
tracks the audio signal with almost perfect accuracy.
MartinLogan ATF diaphragms are constructed of extremely low
mass Dupont Kaladex® PEN (polyethylene naphthalate)—a
material chemically similar to the low-mass PET (polyethylene
terathylate) film used in MartinLogan's generation 2 electro-
static transducers, yet capable of handling the high thermal
requirements required for stable magnetic thin film operation.
High Field Strength
—Superb Control and Efficiency
With a field strength almost 2000% more powerful than
traditional systems, Neodymium iron boron (NIB) rare-earth
super magnets are one of the world's strongest commer-
cially available magnetic materials. This incredible field
strength proves ideal for maintaining perfect control over
the low-mass Kaladex diaphragm. Super-low distortion
levels, high-resolution, and crystal-clear transparency are
just a few of the benefits resulting from this superb combi-
nation of low-mass diaphragm and high field strength.
Push-Pull Operation = Ideal Linearity
Linearity is another factor contributing to a loudspeaker's
ability to achieve ultimate clarity, detail and resolution. By
positioning neodymium magnet arrays in a push-pull con-
figuration, MartinLogan ATF transducer technology maintains
uniform diaphragm control, regardless of position as it
traverses the entire audio signal. The push-pull concept is
a major contributor to the linearity and sonic superiority of
ATF transducers.
Direct Full-Surface Drive
Provides Outstanding Clarity
Unlike traditional voice coil driven systems, ATF diaphragms
are directly and uniformly driven throughout their entire
surface. This full-surface drive system results in ultra-fast
transient response with no cone break up and the ability
to accurately reproduce sound with great delicacy, nuance
and clarity.
Figure 17. Cut away view of an ATF transducer. Note the simplicity due
to minimal part usage.
ATF (Advanced Thin Film) 11
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