Whitepaper

DALI A/S [phone] www.dali-speakers.com
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For optimum control of the cone
excursion, the woofer features dual
spiders, situated 12 mm apart. In this
way the voice coil maintains a 100%
piston-like behaviour, even at very high
sound pressure level.
Altogether DALI’s low-loss approach
is implemented to the maximum. This
goes for the surround as well. Made
from wide, natural rubber, this part
of the suspension also guarantees
linearity across the entire 25 mm
cone excursion. Even the oversized
litz wires are made from solid silver
clad 99.999% oxygen free cupper for
optimum signal feed.
The chassis is made from aluminium to
prevent any magnetic loss. And lots of
research has gone into optimizing the
entire construction for lowest possible
mechanical and magnetic loss, and to
ensure a free airflow.
The chassis features 10 slim legs which is more than the typical amount. Instead these legs are sleek and
optimized for a free airflow. This reduces over- and underpressure behind the spiders, resulting in the lowest
possible mechanical loss and better cooling.
PASSIVE RADIATOR
The two side-mounted woofers share
much of the technology from the active
driver. Cone geometry is identical to
the down-firing woofer, and the cone
material is also carbon fibre. The
‘upper’ part of the chassis is the same
– 10 legs and identical suspension.
However, there is only one spider,
and of course no voice coil or magnet
system behind it.
None of this is due to the visual
appearance, however. The whole
purpose of the passive radiator is to
follow the movements of the active
woofer. Though it looks simpler
than the active woofer the passive
radiator has been through hundreds
of hours of careful designing to
achieve the exact same tonal
balance as in the active version.
An example: Embedded in the cone of
the passive radiator is just the right
amount of zinc alloy to achieve the
desired weight. Only with the correct
weight and distribution of weight you
will get the excursion characteristics
you are looking for. Zinc alloy was
chosen due to its density and non-
magnetic properties.