Aurousal is a relatively new operation.

It started out with a smart-looking standmount speaker called the A1, based on a solitary port-loaded 'full range' Jordan drive unit with a 90mm metal foil diaphragm (that's claimed to flex progressively towards higher frequencies).

As is usually the way with such systems, this crossover-less system had fine coherence, but delivered limited performance as one moved towards the top and bottom extremes of the audio band.

Added sensitivity

The £1,650 per pair VS floorstander is intended to counter both these areas of criticism, while adding some extra sensitivity and loudness capability.

Instead of a single metal-diaphragm driver, it uses two in parallel (effectively rather more than doubling the radiating area) and uses its much larger floorstanding enclosure to load them with a variation on the transmission line theme.

There is also a tweeter, included as a 'variable' option: it only augments (rather than replaces) the main drivers and a little knob tucked next to the input terminal pair allows its output level to be adjusted (upwards from zero) according to personal taste – a neat example of having one's cake, yet also being allowed to eat as much or as little of it as one likes.

Sturdy build

The enclosures (on our samples) came in a particularly handsome real wood veneer. The standard choice available here is between light and dark cherry veneers, or piano black lacquer at an additional price premium of £200.

Built from veneered 20mm panels, this substantial enclosure comes fitted with a little black chamfered plinth, which accommodates the well-founded, though rather blunt spikes and just slightly extends the footprint and stability margin.

The enclosure is reinforced by an internal vertical partition and is said to load the main drive units by a variation on a quarter-wave transmission line theme, where the line is terminated by the mass of air in a reflex port.

It's difficult to say exactly how this operates or is implemented, but that's always been true of transmission lines in general, as their impedance traces look just like a much simpler reflex-ported arrangement. The design is apparently based on work by Dr Martin J. King, and further details may be found at www.quarter-wave.com.

Improved imaging

Ted Jordan was one of the earliest pioneers of metal diaphragm drive units and has been refining his designs for more than thirty years to create the controlled flexure that enables practical full-range operation.

Although the cones used here are just 90mm in diameter, the combined area of the pair is rather more than the cone area of a nominal 165mm unit and the effective area of the two drivers is actually rather larger still, because of the way they couple acoustically. At the same time, because the width is just 90mm, good lateral dispersion will be maintained to a reasonably high frequency.

By using a twin driver arrangement, as here, the sound radiation pattern is modified from a point source to something moving towards a line source. Whereas a point source effectively radiates sound in a spherical pattern, the pattern generated by a line source tends towards cylindrical, increasing the 'throw' into the horizontal far field and reducing the relative quantity of sound radiated upwards and downwards, which should improve stereo imaging.

Sound performance

Full-range-driver speakers rarely generate sufficient output towards the top and bottom ends of the audio band, but the VS, with its port tuned to around 33hz, turns out to have more than ample sub-55hz bass output.