Super Eclipse Series III
On
Jan.15/ 03, Coincident Speaker Technology began shipping The Super
Eclipse III. The Series III represents a significant sonic advance. The
new Super Eclipse is smoother in the midrange, more delicate and
detailed in the highs and the bass is tighter and more coherently
integrated as well as being 1.5 db more sensitive. The end result is a
speaker that now sounds like a smaller scale Total Eclipse. (This
description did not apply to the previous versions of the Supers.)
Design Goal:
To
create a loudspeaker with the sonic attributes of the ground breaking
Total Eclipse, but in a more compact, affordable package. This
loudspeaker would be state of the art on both micro and macro levels
and could be driven by the finest amplifiers without compromise. While
not inexpensive, the speaker still had to be affordable to the serious
music lover. The speaker had to possess the holographic imaging
qualities of the best point source transducers, reveal low level detail
of the finest electrostatics, and provide the explosive impact dynamics
of the largest cone based speakers. This loudspeaker would utilize only
the very best drivers, a completely, non-resonant, enclosure and the
most transparent crossover components. No detail, no matter how
seemingly minor, would be deemed insignificant if sonic quality could
be compromised. In order to be driven by state of the art triode and
OTL tube amplifiers, speaker sensitivity had to be at least 92db and
equally important, the impedance modules had to be nominally 14 ohms,
never dropping below 10.

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Tweeter:
The
Super Eclipse III incorporates the identical tweeter as used in our
reference speaker, the Total Eclipse. This silk dome, specialized
version of the state of the art Scanspeak Revelator is a no
holds-barred quest to offer the finest high frequency reproduction
currently available.
It uses a powerful double
magnet assembly for high power handling capability and very low
resonant frequency of 550hz. A vented pole piece and special cavity
damping techniques reduces spurious resonances to insignificance. While
most other tweeters use flimsy, high resonant front plates made of thin
plastic, the Super Eclipse tweeter's front plate is manufactured from
thick aluminum.
The dispersion characteristic of this tweeter is so wide that even flat
frequency response is maintained to beyond 20khz at 30 degrees off
axis. Truly incredible performance! The Super Eclipse tweeter is highly
detailed, refined, and pure sounding, while at the same time is smooth
as silk.
The new tweeter's design goals were: - Maximum dynamic linearity.
- Ultra low coloration.
- State of the art retrieval of outer AND low level detail.
- High sensitivity AND high power handling capability.
A
daunting task to be sure, but the critical and commercial success of
our Total Eclipse loudspeakers was reflective of our success in
achieving these lofty goals.
To quote from a noted and respected audio reviewer on this new tweeter:
"...
and that treble ...mahhhhvelous, darling- more open, more extended,
more revealing, yet not even the slightest hint of fatigue, brightness
or glare even with bad recordings. The titanium tweeter (previously
used) would reveal the flaws in a recording in a less, um, merciful
manner."
The development of the new tweeter incorporated some very novel ideas:
- To
achieve this new level of resolution required a totally new coating
process on the silk dome. It is a highly complex procedure, done by
hand and involves multiple coats of a specially formulated compound
which not only increases dynamic linearity but critically damps
virtually all cone resonances at the same time.
- Furthermore, the double magnet assembly is housed in a uniquely developed chamber that is devoid of any resonances.
- A completely new magnet system eliminates electrical phase shift.
- The high gauge, aluminum front plate has exceptional linear directivity controlled down to lower than 2khz.
The
end result is a tweeter capable of high frequency reproduction that
sets new sonic standards. Harmonically complete, astounding retrieval
of detail, precise transient response, maximum dynamic linearity with
absolutely no compression or resonances.
Midrange/woofers: (Super Eclipse III)
Only
the finest 5.25" carbon fiber cone units were deemed appropriate and
were therefore selected. Only the most skilled craftsman makes them by
hand and only after carefully inspecting each part to ensure the
highest quality and absolute consistency. The goal: A loudspeaker
without compromise.
Indeed, these drivers are
the most expensive units of their type because quite simply, they are
the best. The extremely stiff, yet light, cone, (only 9.6 grams), give
tremendous bass precision and midrange detail.
To ensure high power handling capability, high sensitivity and a high
impedance modulus, holographic imaging, vanishingly low distortion and
unrivaled detail retrieval, dual 5" units arranged in a D'Appolito
configuration was decided upon.
The D'Appolito arrangement was chosen due to the many inherent
advantages of the design (i.e. greater sensitivity and enhanced dynamic
performance and power handling capability due to the coupling of the
midrange/woofers). However, the endemic drawbacks of this design as
previously configured, were formidable and had to be, at the very least
ameliorated, better still vanquished. Here is where six months of
research and development ensued.

The textbook D'Appolito alignment was plagued by small degrees of
lobing in the vertical plane, but severe lobing in the horizontal.
After thorough analysis of the mathematical relationships of the driver
spacing, it was ascertained that not only is the distance between the
midrange/woofers to the tweeter critical, the distances between the
midrange/woofers themselves are of fundamental importance. Furthermore,
these distances are dependant upon the crossover slope and frequency.
Therefore, what developed was the acknowledgement of the
interdependency of the driver size; driver spacing, and front baffles
area, crossover frequency/slope. A change of one variable mandates an
alteration of another. From myriad computer simulations, mathematical
calculations, prototype testing and aural evaluations, what emerged was
a totally new approach to the D'Appolito configuration that is
responsible in large measure for the sonic breakthrough of the Super
Eclipse. (Indeed, this novel methodology is presently the subject
matter of a pending patent application).
The summary of these conclusions is as follows:
1.The D'Appolito alignment is optimally applied to midrange/woofer
drivers no larger than 5.25" in diameter. Any larger mitigates against
the optimum spacing between the midrange/woofers and the tweeter, (as
measured from the driver centers).
2.First order crossovers are essential to maintain perfect phase relationships and time constants.
3.The crossover frequency does not have to be as low as previously believed, (typically 2khz).
4.The spacing between the midrange/woofers and the tweeter must be asymmetrical by an amount measured in mm.
5.Flat off axis frequency response requires absolutely no front baffle diffraction effects.
When the design is optimized, as is the case with the Super Eclipse,
all lobing in the vertical plane is virtually eliminated and horizontal
lobing is minimized to the point where flat to 20khz response is
achieved up to 3- degrees off axis. Sonically this translates to a
vertical sweet spot that extends essentially from floor to ceiling.
Indeed, listen to the Super Eclipses while standing or seated and very
little difference will be observed with regard to imaging or tonality.
In the horizontal plane, listening while moving from side to side will
still provide the listener with superb focus and dimensionality.
Special Features of the Midrange/Woofer Drivers:
-Precision
cast and surface treated carbon fiber cone coupled to a natural rubber
surround prevents any sign of midrange resonance.
-Very large magnet structure for improved sensitivity and transient response.
-Heavy copper rings mounted above and below the T-shaped pole piece
greatly reduces non-linear and modulation distortion and increases
overload margins.
-Very rigid injection molded chassis made from high purity magnesium,
keeps the critical driver components in perfect alignment.
The net result is midrange/woofer performance that sets a new standard
for detail delineation and imaging precision combines with dynamic
realism.
Woofer:
To accomplish the goals of high sensitivity and high impedance, coupled
with low frequency performance that is dynamically unrestrained,
weighty, impactful, and a seamless blend with the sonic characteristics
of the mids and highs, required the use of a pair of the finest 8"
woofers money can buy. The woofer chosen for the Super Eclipse uses a
huge magnet assembly with a 2" voice coil. A very stiff, specially
treated paper cone is almost impervious to cone break up or flexing. It
uses a novel long stroke, low reflexion magnesium basket that is so
rigid that unwanted movement is totally prevented. The thick yet
flexible natural rubber surround effectively dampens the cone and
reduces distortion to vanishingly low levels.
The dual woofers are specifically tuned to provide very tight and
articulate bass with tremendous impact and dynamic explosiveness.
Enclosure:
To
create a loudspeaker with the imaging qualities of a mini monitor while
simultaneously providing realistic weight, impact and dynamics of a
large speaker mandated the use of two enclosures per channel.
Therefore, the tweeter and midrange/woofer drivers are housed in a
sealed sub enclosure. This sub enclosure's internal volume has been
computer modeled to provide a perfect "Q" of .707. Furthermore, the
internal volume of the sealed enclosure provides for the midranges' low
frequency roll off point, thereby eliminating the need for a large
value capacitor to be inserted into the signal path. The end result is
greater signal purity.
The front of this
enclosure has beveled edges leading to the drivers to eliminate
diffraction effects so that imaging and high frequency purity will not
be adversely affected.
The dual 8" woofers are mirror imaged side mounted in a separate
enclosure that has an internal volume 8 times that of the top
enclosure. The very narrow profile of the system, (a mere 8" wide,
chosen to maximize spatial reproduction), is maintained by extending
the depth of the woofer enclosure to 16". The side mounting of the
woofers also proves highly advantageous in providing flexibility in
room loading thus helping to avoid standing wave problems. Furthermore,
due to the side firing nature of the woofers, interference effects
between the mid and high frequencies and bass are dramatically reduced.
This prevents the low frequencies from impinging upon the purity of the
mids and highs.
All
Coincident enclosures are constructed form the most rigid, non-resonant
material we have tested: 1" MDF hardwood. Additionally, all Coincident
enclosures are tuned to a sonically benign fundamental resonant
frequency of 350hz.
Unique to the enclosure
built for the Super Eclipse III is the use of an elaborate bracing
scheme to create an enclosure with virtually no sonic signature. The
combination of 1" MDF hardwood, sealed sub enclosure for the mids and
the tweeter, plus a highly sophisticated internal bracing system puts
the Super Eclipse into a category of loudspeaker unique at its price.
Furthermore, internal standing waves have been effectively banished due
to the computer designed enclosure dimensions.
In
short, Coincident enclosures have virtually no sound of their own.
Therefore, the Super Eclipse III' reproduction takes on an open,
spacious quality only previously heard in boxless speakers.
Crossover:
All Coincident crossovers are first order designs, (for reasons of
sonic purity and phase coherency), utilizing the finest polypropylene
capacitors, large gauge air core inductors and metal oxide resistors
and are matched to within a 1% tolerance range. The entire crossover is
hardwired, eschewing circuit boards or terminal connectors because they
degrade sonics and deteriorate over time. All Coincident crossovers are
computer designed and then fine tuned by scrupulous aural evaluation.
First order crossovers can only be used with drivers possessing the following qualities:
1.High power handling capability.
2.Smooth roll off characteristics.
3.Wide bandwidth.
The
Super Eclipse III drivers are quintessential examples of the above
noted characteristics. All the drivers can handle in excess of 200
watts continuous, have no resonances within the audible range and are
capable of flat frequency response greater than 2 octaves beyond their
crossover points. Additionally, all drivers used in the Super Eclipse
are matched to within .1db to ensure absolute unit-to-unit consistency
and precision performance.
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