Naim OVATOR S-600 BROCHURE

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Ovator S-600: Design, engineering and technology

Southampton Road, Salisbury SP1 2LN, ENGLAND

Introduction

High-end hi-fi speaker design is a multidisciplinary
endeavour embracing elements of acoustics,
mechanics, materials, vibration, electronics and musical
psychology. And thanks both to the extraordinary
discrimination of our ears, and our hard-wired sensitivity
to ideas and emotions expressed through music,
success in speaker design requires that the elements of
each discipline be thoroughly optimised. A successful
high-end speaker is truly more than the sum of its parts.
So the story of the Ovator S-600 is not simply that of a
new drive unit technology, it is one of the optimisation of
a multitude of interdependent elements where even the
apparently mundane can have an influential role to play.

The Ovator S-600 builds on proven Naim speaker
design techniques while simultaneously introducing new
technologies, new ideas and new refinements; all
incorporated in a scheme that offers a striking yet subtle
aesthetic and provides great ease of installation.

Paul Neville

Naim Audio

Fig. 1 Plinth and Floor Spikes
The Ovator S-600 Plinth, Cabinet and Driver Chassis

The foundation of the Ovator S-600 is its plinth. An
extremely rigid high pressure aluminium die-casting, the
plinth provides location for the cabinet, floor spike
fittings, and mounting points for the passive crossover
module (or active loom interface) and terminal panel.
The floor spike fittings comprise conventional M8
tapped holes at the front, but at the rear the form of the
plinth and the detail design of the spikes enables them
to be conveniently adjusted and locked from above. The
spikes themselves are manufactured from hardened
stainless steel.

Connection Bosses

Fig. 2

Plinth Leaf Spring

Leaf Spring

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The Ovator S-600 cabinet is attached to the plinth at
two locations towards the front and via a leaf-spring at
the rear. The leaf spring is a 200mm stainless steel
bar that runs laterally underneath the cabinet and
attaches centrally to its underside. At each end the
leaf-spring is bolted, via tapped bosses, to the plinth.
The front locations comprise stand-off bosses through
which a bolt is inserted and screwed into the cabinet.
A slot feature either side of each boss introduces
some controlled compliance to the front cabinet
locations that in combination with the leaf-spring
results in the cabinet rotationally (forward and
backward) decoupling from the plinth above 12Hz.

The entire plinth and cabinet system was the subject
of Finite Element Analysis modelling to analyze,
predict and fine-tune its vibration characteristics with
the aim of ensuring that any resonant behaviour within
the audible band is minimised. Limited decoupling of
the system outside the audible band is inherent in
achieving this aim. The cabinet/plinth leaf-spring was
first introduced on the Naim Allae loudspeaker
although the leaf-sprung cabinet concept goes back to
the Intro and Credo.

Fig. 3 8” Drive Unit Basket

Contact Points

Fig. 4

BMR Sub-assembly

The Ovator S-600 BMR Drive Unit

The Ovator S-600 BMR (Balanced Mode Radiator) has
its own separate enclosure formed by a 12.7mm thick
aluminium alloy cylinder nested within the cabinet. A
unique suspension system comprising two, four
element, duralumin circumferential leaf-springs
decouples the BMR module from the rest of the cabinet.
The suspension system prevents low frequency
mechanical energy from the bass drivers interacting
with the BMR and stops mid/high frequency mechanical
energy being transmitted to the cabinet. The cylinder is
held by one leaf-spring at the front of the cabinet and
one at the back. The system was Finite Element
Analysis modelled and the design optimised to provide
a decoupling from 4Hz – more than six octaves below
the beginning of the BMR pass-band. The BMR
enclosure is gradient filled with a mix of wool felt and
reticulated foam and has a vent at the back so that
changes in temperature or atmospheric pressure do not
impact upon performance. A simple transit system
locks-up and protects the suspension system during
shipping.