Bowers & Wilkins 600 Series 3 - Manual (Page 3)

B&W is a rarity among loudspeaker manufactur-
ers. Our products meet the needs of all parts
of the market, from high street customers to
the world’s most demanding recording studios.
When we accomplish something extraordinary
at the top end – such as Nautilus ™ – there is
a ‘trickle-down’ of knowledge, insight and
technological innovation into the development
of our mainstream products, which ultimately
means they rise above their more ordinary rivals.
The same challenges of acoustic control
arise wherever the reproduction of sound takes
place. And those challenges can only be solved
by ingenuity and intelligence. The same team
of engineering perfectionists involved in the
five-year development of Nautilus ™ and its
spin-off Nautilus ™ 800 Series is behind the
600 Series 3. The range continues the evolution
of B&W’s leading-edge drive unit technologies
into popular applications.
Our latest set of drive unit refinements
includes an improved tweeter response at very
high frequencies, reduced distortion from the
midrange drivers and a crisper ‘slam’ from the
bass units. All round, it’s a sound that’s hard
to beat.
Driven by invention
Tweeter
Within every 600 Series 3 cabinet is one of
these: a Nautilus ™ -derived, tube-loaded tweeter.
One of many breakthroughs made by Nautilus ™ ,
it soaks up unwanted sonic radiation from the
back of the diaphragm by trapping it in a tube
until its energy has been absorbed. What
emerges from the front is the purest high
frequency output.
To push the unit’s response even higher,
the 600 Series 3 features a stiffened bond
between the tweeter dome and the voice coil
bobbin. The strengthened assembly allows the
ultrasonic frequencies of new digital formats
such as DVD-A and SACD to be delivered
with diamond precision.
Nautilus ™
Nautilus ™ emerged from B&W’s University
of Sound R&D facility after five years’
painstaking development. Briefed to stop at
nothing in the quest for a perfect loudspeaker,
our engineers arrived at a set of drive units
whose tapering, tubular forms spirited away
every trace of internal resonance.
For the bass unit, the natural form of
a seashell – a coiled tube – delivered the most
natural and untainted sound. A host of
advanced audio technologies lay inside the
speaker, which was selected by the Design
Council as a Millennium Product and hailed
by reviewers as ‘possibly the best loudspeaker
that money can buy’.
Chassis
Controlling the movement of air and transfer
of energy behind the bass driver is a science
in itself. The object is to reduce the volume of
solid material in the supporting structure while
trying to maintain or improve its rigidity.
Following the example of the FST ™
midrange driver of the Nautilus ™ 800 Series,
our new bass/midrange drivers reduce
coloration by adopting a more ‘open’ chassis
structure, with slender ‘legs’ that are contoured
to a rounded, aerofoil-like profile. Reducing the
reflective area reduces echo from behind the
cone which would otherwise time-smear the
sound. The two-layer baffle, designed to add
stiffness to the cabinet, is also cut away around
the rear of the driver, allowing air to move freely
from the back of the cone. The result? The
cone reacts more to the music, and less to
what’s inside the speaker.
Kevlar ®
It’s round... but it’s square. B&W patented its
distinctive yellow woven Kevlar ® cones in the
seventies when it was noticed how the fabric
– used in bulletproof vests – reduced sound
coloration. Using lasers to detect the tiniest
of cone vibrations, our engineers revealed
how the tight, square weave of the material
dissipates the concentric standing waves
that build up in conventional homogeneous
materials. Of course, Kevlar ® itself is only part
of the story – as subsequent imitators have
discovered – and our years of experience have
enabled us to refine what is still unique to B&W:
that optimum blend of Kevlar ® with selected
resins, damping materials and cone geometry.
In the 600 Series 3 midrange and
bass/midrange drivers, we have improved
their response in the upper frequencies by
better matching the stiffness of the voice
coil bobbin to the neck of the cone. A minor
refinement perhaps, but it gives a smoother
transition to the tweeter and improves the
sense of openness.
Aluminium
It’s definitely not heavy metal. Even so,
the new lightweight aluminium bass driver
(on the 2 1 ⁄
2
-way DM603 and 3-way DM604
loudspeakers) helps to deliver the high
quality ‘slam’ that is so vital to music
with fast, tight bass lines and drum kicks.
Aluminium is relatively stiff compared to
alternative materials, and allows the cone to
withstand deformation from the high internal
air pressures generated behind it as bass
frequencies are pumped out .