|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.)
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.
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.
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.
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.
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.
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.