AUDIO Verstärker und DACs (Vorschau)

standard. Who wants to swap these for
the massive supplied spikes, can do so
after the final position has been determined.
Once positioned, the Stella presents
a strikingly elegant and light appearance
due to its individual middle and high range
enclosures floating airily on top of each
other. And since Focal delivers all Utopia
models in all colours of the RAL chart at
no premium, the technology behemoth
turns into a sounding sculpture that can
be adjusted precisely to any domestic
style. Even extravagant special requests
are no obstacle and will be realised for an
adequate charge – on my recent visit to
the Focal company in Saint-Étienne, I saw
a pair of Stellas finished in some kind of
japan lacquer, with gold leaf decorations
shimmering through its dark red surface
– gorgeously beautiful. Focal owes the
extensive freedom of surface finish to it´s
own cabinet factory in the Burgundy, which
furnishes the woodwork for the Electra an
the Utopia series. So instead of importing
containers full of “piano lacquer“ cabinets
from overseas, one has deliberately chosen
the in house manufacturing, even
though it is far more expensive.
All drivers and crossovers are handbuilt
at the corporate headquarters on the edge
of the Massif Central. The great vertical
range of manufacture makes the Utopia
a “Made in France“ product even with a
narrow interpretation of the term and in
the first place allows the technological
tour de force which awaits us behind the
Stella’s beautiful facade.
The most important unique characteristic
and distinctive feature of the Stella
is its electromagnetic bass that Focal
otherwise uses only in its big sister and
which is pretty unique in the entire speaker
world. The EM woofer, represented
here in a 13“ version, solves a problem
which always occurs – and especially in
woofers – if a designer targets an extreme
Permanently
loaded: With its
power supply in
medium setting,
the magnet coil
consumes a constant
30 Watts.
When set to high,
this value rises
considerably.
bandwidth without sacrificing on efficiency.
The stronger and more efficient the
woofer drive is, the easier it will be to
solve this conflict of aims. Here the most
essential factor is the magnetic field
strength in the air gap, in which the voice
coil is moving. From the old ferrite to
cobalt and today’s rare earth materials
magnets have become ever stronger, but
at some point one hits a wall: still stronger
and at the same time more linear fields
require electromagnets. And thus you will
see no classical magnet ring on the rear
of the Utopia woofer’s mighty die-cast
basket, but a thick copper coil which alone
tips the scales at 5 kg. This magnet
coil is energised by DC delivered by an
external power supply and can create
gigantic field strengths when needed:
while the former Utopia 13“ woofer with
its “multiferrite“ engine had already hit
the limit of what is possible with conventional
drives, the field coil woofer simply
doubles the field strength in the air gap
from 0.85 to 1.7 tesla.
But the garantuan driving force is just
one of several benefits. A point nearly as
important is that the EM woofer is virtually
adaptable at will by changing the field
coil current to render the “Q factor“ of
the chassis variable. Focal lets the user
select between three driving forces which
can be switched during operation. However,
this must not be seen as a plain bass
level control. Its effect is much more subtle
and also slightly affects the bass level,
but primarily changes the attack and decay
parameters in the low range. Hence
the speaker can be adapted to the room
and the amplifiers used in a way that other
super speakers simply lack. Particularly as
there are other adjustment options waiting
for the fun-loving high end disciple behind
a hinged cover on the rear which is reminiscent
of a liquor cabinet. A most exciting
feature is the jumper which controls the
bass response at the lower end of the
frequency range: from a somewhat early
rolloff we’re passing in three steps to the
default setting with utmost linearity and
on to a little bass boost with a slightly
steeper rolloff way down. But the descriptive
pictographs on the jumper panel are
drastically exaggerated – as our lab measurements
show they also produce very