ISOBARIC DRIVE SYSTEM

On the underside of the Discovery II, two Tactic II drive units combine to create an Isobaric Drive System. The Isobaric Drive is responsible for reproducing incredibly tight and controlled bass response that integrates perfectly with the midrange Tactic II drive unit.

The Isobaric Drive System results in two lightning fast, highly dynamic bass woofers which create the full range of bass notes up to 25Hz. Although the Isobaric Drive System operates at a much higher load than the midrange units, the load is shared by two drive units working together, allowing the Isobaric Drive System to remain perfectly integrated with the midrange units. This degree of speed and dynamics cannot be achieved with conventional large woofer designs.

TACTIC II DRIVE UNIT

There are no transient delays in nature – when a singer sings, or a drummer strikes you hear the sound almost instantly. But when a drive unit tries to replicate this sound from a recording, the transient response time, although minute, is easily detected by the ear and the brain. When designing a drive unit, it is critical to reduce the transient response time as much as possible. Any delay, informs the brain that what is being listened to is in fact a recording and not a real human voice or instrument.

Wilson Benesch developed the original Tactic drive unit and subsequent Tactic II drive unit around this philosophy. We employed a light cone material, with phenomenally powerful NdFeB Rare Earth Magnets, with a highly evolved motor geometry to optimise flux. The result was a dynamic drive unit that could excurse through the in and out range of its movement during use very quickly and under a high degree of control. The original Tactic design was described as “lightning fast” in the first test reviews.

PORT TUBES

The Discovery II is a bass reflex ported enclosure. Two ports enhance the bass and midrange frequency output, with one port feeding the bass enclosure and the second feeding the midrange enclosure.

Each port has been tuned optimally through adjustments to their length in accordance with the specific characteristics of the Tactic II Drive Units.

SEMISPHERE TWEETER

Designed and manufactured in house, the Semisphere has been developed to match the Tactic II Drive Unit, creating seamless integration across the mid-high frequency band. At the heart of the Semisphere is the Silk-Carbon Hybrid Dome. The hybrid dome tweeter, retains the natural sound of a soft dome tweeter, remaining free from sibilance. However the addition of carbon fibre through a proprietary technique, allows the Semisphere to remain flat through the frequency range to 30kHz.

Built around the dome is a combination of highly engineered components, which have been precision machined in house at Wilson Benesch. At the front a curved front plate creates the ideal launch surface for high frequency sound. To the rear of this is a complex motor front and rear plate that hold a ring of six powerful rare earth magnets. The design allows optimal venting and allows the Semisphere to remain cool during extended use.

A.C.T. MONOCOQUE

A sophisticated three-layer composite structure comprised of carbon fibre, high compression blast core and glass fibre. In terms of energy damping and therefore signal-to-noise ratio, the A.C.T. Monocoque exceeds with consummate ease the materials traditionally used in loudspeaker design.

Wilson Benesch have optimised the A.C.T. Monocoque by creating a curved form. The geometric form of the cabinet negates standing waves by reducing the number of flat surfaces on the loudspeaker surface. Thus any sound waves interacting with the surface of the A.C.T. Monocoque are diffracted across a wide angle and thus diminished. As a result such distortions are impossible for the ear to detect, allowing the loudspeaker to disappear within the listening space; stealth like the loudspeaker creates a wide open and life like soundstage.

CABINET CONSTRUCTION

The Discovery II makes considerable advances on the original design in every aspect. In terms of the fit and finish, perhaps the most tangible element visually that sets the two designs apart are the beautifully engineered top and base boards and the Geometry Series styled foot.

These components are each machined from large aluminium billets in house at Wilson Benesch to create a phenomenally stiff and perfectly crafted structure.

Much like the Endeavour, the precision CNC machined base board is an impressive structure designed to house the powerful Isobaric Drive providing unyielding structural integrity and housing other critical elements such as the port tubes, A.C.T. Monocoque, side cheeks and spine. Total engineering.

KINEMATIC LOCATION

First introduced in the kinematic bearing design in the Wilson Benesch A.C.T. One Tonearm in 1991, the bearing was designed on the principles of kinematic coupling. The fundamental of kinematic coupling is to selectively eliminate each one or all of the six degrees of mechanical freedom that any physical body has.

In the Discovery II, three 14mm steel threads, each tipped with a 6.75mm steel ball, meet with three 6.75mm steel balls, held captive inside the floor protector. This creates a triangulated structure, with a contact point of less than 1mm Sq. This provides high-integrity, stable location of the loudspeaker.