CABASSE LA SPHERE - DATASHEET 2 User manual

La Sphère

La Sphère System,
The acoustic master piece
Cabasse achieved the acoustic Holy Grail with La Sphère, the rst full range system behaving like a true point source.
Made possible only through the combination of the unique Cabasse technologies and innovations in loudspeakers and
digital processing:
TC23 three-way co-axial driver
The three-way co-axial transducer forms a portion of a pulsating sphere and presents
a constant directivity index, as the smaller membranes are not affected directivity
wise by the larger ones.
This is obtained with no compromise on the linearity, efciency and power
handling parameters of each driver. Our engineers have used all their expertise
and experience in the exclusive use of high end technologies; like the in
house die-casting of Rohacell foam, or the most powerful rare earth magnets
available. Fitted in a lens made from a sandwich of composite materials with
high damping capacities, the TC23 operates over the 80 Hz to 35,000 Hz
bandwidth.
The production of the new polyether tweeter membrane is carried out by
computerised machines created by our team. The process is automatic but
very time consuming, preventing any alteration of the characteristics of the
material involved and ensuring accurate and identical parameters for every
item produced. Rigid, light and damped, this diaphragm brings a perfect linearity
to the response curve up to 35,000 Hz, with an excellent power handling and
reliability.
The new membrane material was also selected for its excellent rigidity/weight ratio
and the perfect mechanical homogeneity with the ring membranes of the midrange
and low-midrange units.
22’ honeycomb dome woofer
To achieve linear reproduction down to 20 Hz and under, our engineers
created a special version of the 22” unit 55ND46 designed for the Saturn 55
reference subwoofer. The basket of the woofer is designed to t a spherical
enclosure and the moving elements to work in a closed volume. Thanks to
the extra rigid, but light, Nomex honeycomb dome structure of the membrane,
the long throw powerful magnet gap and the double spider, the combination
provides high levels, speed and accelerations without the requirement of a
huge loading enclosure.
This is a key element because the sphere behind the three-way co-axial
TC23 has to be of a decent size, so as not to interfere with the quality and
directivity of the upper frequencies, while applying the Spatially Coherent
Source principles.

QC55 : the four-way coaxial unit
The design of the lens, holding the TC23 in front of
the 22” woofer on the same axis to form a four-way
point source, required very long theoretical and
experimental studies including tests of several versions
and numerous lter modules. The shape succeeds in
creating a portion of pulsating sphere with minimum
diffraction effects. The shape of the arms and of the
front panel of the lens contributes to the quality of the
high and mid frequencies, whereas the shape and the
damping of its rear side have been designed for the
low-midrange specications.
A spherical enclosure
The spherical shape of the cabinet loading the woofer presents numerous advantages:
- rigidity inherent to the shape.
This is essential to avoid any low frequency vibration that might create noises or a fuzzy sound scene. Thanks to the resulting
extremely good pressure resistance, the shape allows use of a very small volume for a 22” woofer and thus provides 96 dB efciency
and a linear response down to 20 Hz, in anechoic room conditions. Any other reference system specifying equivalent characteristics
in the low frequency range needs a minimum of four to six times more volume for the woofer(s).
- no standing waves.
There are no parallel surfaces, so it is not necessary to ll the enclosure with a lot of damping material and internal bracing. The use of
those items reduces the internal volume of air available to load the driver, thus requires the use of a larger volume, thus lager panels
that require more bracing and damping...
- perfect symmetry in every direction and no diffraction effects from 20 to 20,000 Hz:
The very essence of the spatial coherency.
There was a hitch when considering a full range spherical loudspeaker enclosure. A problem that required a long term collaboration
with a French designer, famous for his variations around spheres and circles, to answer the following question “which type of stand
will be able to position the tweeter from La Sphère at the optimal height, ensure a no compromise stability of the system even at very
high low frequency sound levels and will not create diffractions spoiling the response coherency out of axis?”
BASS L. MEDIUM H. MEDIUM
HIGH

Looking at La Sphere, the answer looks obvious, and even
beautiful. However, the impressive number of drawings, plans,
models and prototypes belies that rst impression. The purity
of the design masks the asymmetry of the shape avoiding
diffractions, the choice of materials for rigidity (die cast
aluminum for the stand) and damping (loaded composite for
the bottom plate, a combination of aluminum and elastomer
for the silent blocks and the cones). For a full coherency of
the system, the hull of the enclosure is a sandwich structure
in which two layers of composite are damped by a special
material originally designed to meet the vibration damping
requirements of air and space machines like Airbus, Ariane,
helicopters and jet ghters.
The hull is straightened with curved wooden bracings and
internally covered with a thick layer of acoustic felt. Finally,
the enclosure is tensed through compression when the QC55
is tightened from the back.
A specic digital ltering
For this system, Cabasse designed a specic ltering module and
digital sound processing software. Thanks to digital delays, the
four acoustic centres are not only on the same axis but on one
point; the cross-over areas are optimised with variable slopes up
to 70 dB per octave. The result is a steady 60° diffusion cone with
a full coherency at the listening spots between direct and reected
sounds.
Such digital processing was possible only with the recent launch
of hardware powerful enough to provide a better sound than the
analogue active lters which have been a Cabasse specialty for
decades. Three years and a team of eight people have been devoted
to the theoretical development of the lter module, its software and
the associated measurement protocol. The nal settings made
through a lot of listening tests and measurements in different rooms,
interspersed with anechoic room measurements and hardware and
software modications. This meticulous process led not only to software upgrades, but also, for instance, to reconsider the design of
the lens of the TC23, with modications to its spherical shape; depth and width; a new damping material on the side; additional waves
on the front side to break diffraction effects and a re-shaping arms of the arms holding the lens.
This mastery in digital sound processing, shared and developed by Cabasse with researchers and students of the E.N.T.B. (an
engineering school and international research centre in the eld of information technologies) turns the one and only four-way co-axial
loudspeaker into a true point source:
one acoustic centre•
optimum impulse response with no noticeable variation in a 60° cone•
absolute linear phase even when the parametric equalisers are being used for room adaptation.•
The spatial coherency is perfect.
A powerful but coherent amplication
The monoblock ampliers of the La Sphère system have also been designed using innovative
technologies offering power and renement in a very discrete size. The “Ice Power” modules
present 90% efciency, ten times more than conventional ampliers. Driven by a 1000 W
RMS amplier, the 22” woofer of La Sphère can be played up to its mechanical limits with no
amplier distortion. The same 1000 W monoblock is used for the low-midrange, with 300 W
versions feeding the midrange and tweeter units. Both versions share the same design and
there is no risk of delay between the ampliers that would kill the linear phase of the digital
processing. The use of ampliers far under their nominal power (never more than 5% for the
high frequencies for instance) for the three upper frequency units avoids any risk of amplier
distortion.
Other sets of ampliers can be chosen if there is no restriction regarding available space,
integration and specications.

La Sphère, the smallest of the great systems
All the acoustic laws have been taken
into account in the development of La
Sphere. No fundamental parameters
have been sacriced in favour of a
technical or marketing option. La Sphère
offers unrivaled technical and musical
specications in a more compact volume
than other ultimate systems. Its placement
can thus be optimised with limited space
or aesthetic intrusion, in a recording studio
or in a living room. Thanks to the co-axial
technology and the application of the SCS
principles, the sweet spot is very wide
whatever the listening distance.
Stereoplay, Germany, January 2007: “Is La Sphère the best loudspeaker ever made? Among all the ones
Stereoplay has been listening to, in any case. It is by far.” (Ist La Sphère etwa die beste Box aller Zeiten? Von
denen, die stereoplay gehört hat, auf jeden Fall. Sogar mit Abstand)
Haute-Fidélité, France, December 2006: “This loudspeaker system constitutes a fantastic pleasure provider as well
as the most sophisticated working tool. Re-mar-ka-ble!” (Ces enceintes constituent un vecteur de plaisir fantastique
tout autant qu’un instrument de travail de la pus haute technicité. Re-mar-qua-ble!)
La Revue du Son, France, September 2007: “Thanks to La Sphère we experienced magnificent musical times…
softness, sensuality, extent and controlled force are reproduced with a stunning realism”. (La Sphère nous a fait
vivre des magniques moments musicaux…la douceur, la sensualité, l’ampleur et la force maîtrisée sont restituées
avec un réalisme stupéant).
Le Monde de la Musique, France, February 2007 : “An incredible technical achievement devoted to music” . (un
formidable exercice technique au service de la musique)
Stereophile, USA, June 2008:“La Sphère sets new standards, both for measurable and audible, for
accuracy in the reproduction of music.”

La Sphère System
LOUDSPEAKER SPECIFICATIONS
Type: 4-way co-axial
Driver: 1 x co-axial QC55 with:
- tweeter: 1” dome diaphragm 4-25 kHz 93 dB (2.83V/1m) 30 W 108 dB SPL
- midrange: 5” P2C ring 0.8 - 4 kHz 93 dB (2.83V/1m) 80 W 112 dB SPL
- low-mid.: 8” Duocell ring 150 - 800 Hz 94 dB (2.83V/1m) 170 W 116 dB SPL
- bass: 22” honeycomb dome 20 - 150 Hz 96 dB (2.83V/1m) 1,000 W 126 dB SPL
Frequency response: 20 - 35 000 Hz ± 3 dB on axis
Frequency range: -6 dB at 16 Hz (open space conditions)
Dispersion within 2 dB of reference response: over 60° arc for any plan,
forming a perfect 60° cone
Standard nish: Glossy Pearl – Glossy Black Pearl
Speaker Dimensions: 140 x 70 x 70 cm – 55.1” x 27.6” x 27.6”
Weight: 100 kg – 220 lbs
4-WAY ACTIVE PROCESSOR SPECIFICATIONS
Cross-over points: 150 – 800 – 4,000 Hz
Variable slopes: 24-70 dB/Octave
Phase linear time alignment of the 4 acoustic centres
Digital parametric lters for room adaptation by Cabasse
Voltage: 100 / 240 V AC – 50/60 Hz
Maximum power consumption: 12 W
Power consumption when off: 0 W @ 230 VAC & 115 VAC
Dimensions (H x W x D): 9 x 44.4 x 31.6 cm – 3.5” x 17.5” x 12.4”
Weight: 8.9 kg – 16 lbs
AMPLIFIERS SPECIFICATIONS
Cabasse BC M300 Cabasse BC REF1000
RMS power (4Ω): 300 W 1,000 W
Peak power (4Ω): 600 W 2,000 W
Voltage: 100-240 VAC 50/60 Hz
Maximum power consumption: 450 W 1,500 W
Power consumption when off: 0 W @ 230 VAC & 115 VAC
Stanby power consumption: 5 W 15 W
Dimensions (H x W x D): 8.8 x 21.6 x 30.5 cm – 3.5” x 8.5” x 12”
Weight: 4 kg – 9 lbs 6 kg – 13 lbs

Cabasse SA - 210 rue René Descartes - BP10 - 29280 Plouzané - Tél [phone]
Fax [phone]
www.cabasse.com
Photos : GPO Morlaix, Alcide Rioche Rennes - Julian Bauer, Cabasse - Because of technical improvements already under way
in our constant search for optimum quality, Cabasse reserves the right to modify all the models presented in specification sheets,
advertising materials and manuals without prior notice.