The
structure of the front baffle needs to reconcile
inertia and damping properties in order
to guarantee the dynamic range and the absence of
coloration in the bass.
A
loudspeaker is a transducer. Its role involves causing
molecules of air to vibrate under the influence
of a voice coil coupled with a membrane. A variation
in electrical current mirroring the musical message
stimulates the voice coil, which (submerged in the
magnetic field) moves “in rhythm” with
the musical signal. The electrical energy is converted
into acoustic energy. This is the principle. In
reality however, in order for this conversion to
be as faithful as possible to the original audio
signal, it is vital that the membrane moves in relation
to a perfectly fixed reference. When the membrane
moves, the chassis must not budge, and its acceleration
must be zero. It should comprise a totally inert
mechanical reference.
Inertia: it’s a mass thing!
The chassis of the loudspeaker is solidly attached
to the front baffle of the speaker system, the baffle.
The mass ratio between the mobile assembly (voice
coil plus membrane) and the frame (the chassis plus
the front panel) must be as high as possible. This
is an application of the fundamental principle of
dynamic range: F = m * gamma. The (gamma) acceleration
taken by the chassis subjected to the moving cone
force “F” must ideally be zero. Consequently,
the mass “m” must be as high as possible:
it must target infinity. Thus, regardless of the
material chosen to produce the front panel in terms
of rigidity, it would be a mistake to forget the
mass. One could easily imagine that a highly dampened
front panel would be the solution to avoid spurious
vibrations set up by the “kickback effect”
but this would be at the expense of dynamic output.
Only a high mass can guarantee the transients. Damping
can never substitute for mass.
New "Advanced “GAMMA” Structure"
The front baffle solution in the Electra 1000 Be
introduces a very high inertia to allow the bass
driver to reproduce the transitory information of
the low register with all its impact. The baffle
is a massive structure of 50mm thick MDF which gives
the front face a very high mass. The new version
is free from any distorting vibration. The new Advanced
GammaStructure keeps the basic principle still used
on the Utopia be series. However, this new development
comes as a follow-up to the performance established
by the Electra 1000 Be IAL tweeter right from 2000Hz.
At that frequency, the old Gamma structure generates
a strong side effect which precludes taking full
advantage of using an IAL tweeter. Side effect appears
when a sudden break in the speaker frame shape occurs,
in case of a sharp apex for example. Hence, a diffraction
problem takes place on the loudspeaker’s side
and the directivity diagram is then corrupted (flower
petal like parasite lobes), linearity is also seriously
altered, prompting an imperious need for new loudspeaker
structure development. Side effect cancellation
induces a more rounded speaker frame on a radius
at least equal to half the wavelength (8,6 cm at
2000 Hz) from both sides of the tweeter, in order
for the signal to spread out around the speaker
without any wave shape alteration or incoherence
caused by a salient angle.
As a result, the IAL tweeter is located in an upfront
position compare to the midrange driver and sticking
out on its aluminum alloy stand. That upfront position
takes into account the delays introduced by the
filter and its wedging has required numerous critical
listening comparative sessions in order to obtain
optimal tone cohesion between the drivers and the
sharpest stereophonic image possible. Also new on
Electra 1000 Be: the loudspeaker structure benefits
from non-parallel panels, which prevent stationary
waves development. Electra 1027 Be internal panels
marking off the midrange enclosure are sharply inclined
as well, in order to prevent internal resonance.
Enhanced listening quality
Every effort is made to remove the source of spurious
vibrations and to provide an outstanding dynamic
output from the bass. The sound image is enhanced
and the tone offers greater differentiation due
to the absence of the coloration from the cabinet.
The midrange and treble registers are consequently
better defined and more transparent as the micro-information
is
transmitted without any “masking effect”.
