Thiel CS3.7 Product Support Bulletin page 4

3.7
CS Components
The Midrange Driver
precisely reproduce every musical nuance while introducing
not even a trace of its own colorations or distortions
caused by diaphragm resonances or electromagnetic
nonlinearity. The most exciting innovation in the CS3.7
is a new midrange diaphragm that advances midrange
performance much closer to this ideal.
The midrange driver's diaphragm is constructed with
an entirely new shape that provides far greater stiffness
than typical diaphragms, even those made from exotic
materials. The diaphragm is shaped with corrugations that
are oriented from the center outward (like spokes) and
act a little like small I-beams to provide enormous strength
in that direction. The large diameter voice coil attached to
the diaphragm gives it strength in the other direction – around
the circle. This design achieves such great stiffness that the diaphragm
continues to vibrate perfectly, as one unit, all the way up to 20 kHz, usually
considered the upper limit of human hearing. Such fabulous vibrational behavior is
unprecedented and allows the CS3.7 to achieve a purity and delicacy of the high frequencies that is truly extraordinary.
This new diaphragm geometry also has a second important benefit that derives from its shape. The diaphragm is basically flat and
therefore has virtually no detrimental effect on the tweeter's output, unlike a normal cone shaped diaphragm that alters the sound
of a tweeter mounted in its center.
Anatomy of a midrange driver
The die-cast chassis A copper sleeve around
rigidly holds the tweeter the center magnetic pole
and midrange in perfect stabilizes the strength of
alignment and virtually the magnetic field and
eliminates transient- reduces the voice coil's
robbing subtle vibrations inductance non-linearity.
of the motor system.
The Tweeter
provides much lower distortion
and higher output than any other tweeter we are aware
of. This is accomplished in spite of a size small enough to
mount coincidently with the midrange driver by a unique
long gap motor system that uses a set of four radial and one
axial neodymium magnets with a total weight six times that
of a typical neodymium powered tweeter. In addition, the
tweeter provides the complete absence of any coloration-
producing diaphragm resonances in the audible range,
a very wide operating bandwidth and very low power
compression. The result is high frequencies of utter neutrality
and effortless dynamics.
4
should, of course,
An extremely powerful The wide magnetic gap,
neodymium magnet in conjunction with the
powers a very large and short-winding voice
deep magnetic gap so coil provides much
the driver can achieve lower motor distortion
both very high efficiency compared with common
and high level, low short-gap designs.
distortion output.
A set of four radially-magnetized and one axially-magnetized
neodymium magnets have a total weight of 2.3 oz. (64 grams),
six times as much as usual neodymium powered tweeters.
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The very large The unique diaphragm
diameter voice coil shape provides
contributes exceptional unprecedented
circumferential strength to stiffness and therefore
the moving system while unprecedented,
providing high power resonance-free operation.
handling and very low
power compression.