Wonder Wall

I am quite confident that surround sound has prompted many a domestic dispute. One partner, keen on the home theatre experience, wants speakers that deliver performance. The other, keen on keeping the home at least moderately stylish, demands restraint. Who can win?

Maybe both, with this extraordinary new – well – sound delivery system from VAF Research.

WHAT’S IN THE BOX

Why not just come clean and call VAF Research’s SoundWall yet another loudspeaker system? Well, because that would be misleading. First, because it is more than just loudspeakers. Second, because it doesn’t look at all like loudspeakers.

The challenge facing VAF Research was to develop loudspeakers that carry ‘invisible’ not as a trademark, but as a legitimate description. Rather than following the usual way of doing this – creating the smallest possible satellite speakers and coupling them with a discreet subwoofer – VAF has effectively turned them into part of the wall. Or, rather, a feature wall.

The feature wall is assembled by attaching a simple wooden frame to the wall, then hanging or clipping to it, your chosen arrangement of thickish panels. Each of these is 120mm thick, and square in shape with 600mm per edge. That 600mm dimension conforms nicely to the size of the ceiling tiles in suspended ceilings, but let us stick with wall mounting.

The SoundWall consists of three elements: an active element, an absorptive element, and a diffusive element. A mix of the three is used to make the result come out right.

ACTIVE ELEMENT

The active element is the part of the SoundWall that actually produces the sound. This has a driver bang in the middle of its face, wtih a coupling of small bass-reflex ports pointing forwards. Like the rest of the SoundWall components, the sides of the panel are beveled inwards at 45 degrees. This makes natural hidden channels behind components that may be used for routing cables.

The driver itself is the well-regarded one that is used by VAF in its Signature I-91 and Icon|195 speakers. It is a 170mm unit, with a 25mm tweeter mounted coaxially at the centre of the larger driver, behind where the dust cap would normally be. A proper crossover network is used to deliver the appropriate frequencies to each driver.

It is magnetically shielded – an essential feature given that it will be effectively forming part of the wall. VAF rates the impedance of the active element at 6 ohms, its sensitivity at 89dB (2.83 volts, one metre) and its frequency response at 52-18kHz, ± 3dB, with a –dB point at 32Hz. Of course, VAF has carefully tuned the bass performance of the enclosure to take account of, and to take advantage of, the fact that it will be placed hard against a wall.

Normally, despite such tuning, speakers near a wall suffer from limited stereo sound staging, and often coloration, thanks to the very close proximity of a room boundary. This is where the other two elements come in. the diffusive element uses what’s called a ‘quadratic residue diffuser array’. This consists of the panel being divided into six long rectangular sections of differing depths so as to provide the best diffusion of specific frequency bands to best effect. It’s job is to scatter sound, to kill the coherent reflections that cause interference with primary sound source (that is, directly from the driver) by sending bits and pieces of audio reflections in all directoins.

The absorber helps achieve a similar end, but by trapping and killing sound rather than reflecting it. This is the same enclosure as the active element, minus the front baffle, and filled with multigraded foam to provide the best effect.

A typical installation will have two, five or seven of the active elements, depending upon whether the listener wants stereo, five-channel or seven channel sound. But the number of absorbers and diffusers can be artfully chosen to deal with unfortuante aspects of room acoustics. Potential purchasers should discuss their situations with VAF Research.

The pricing of the system depends upon how many of the different types of panels will do the job, both in terms of decor and acoustic delivery. A five-channel system providing a 3 metre wide by 1.2 metre tall section at the front of the room, accompanied by three panel surround sections, would cost around $10,500. a simple stereo system consisting of five panels (two of them active) would come to $3,500.

LISTEN UP

Has VAF Research been successful in making its loudspeakers invisible? Look again at the front cover of this issue and judge for yourself. Those panels behind the plasma display constitute a SoundWall. What you can’t see in the picture is a horizontal row of panels at the other end of the room, providing surround sound and a further taming of room acoustics. Yet still looking like a room feature, rather than a device to serve the utilitarian purpose of providing home entertainment.

I should note that VAF has made provision for the grilles to be screen printed according to customer order – even to the point of several panels together constituting one picture – so the SoundWall can also be an active artwork.

As pictured on the front cover, the SoundWall arrangement has blank panels behind the plasma display, but i could see these being omitted, aside from some filler panels on the edges to allow the display to be set back so that its face is level with the rest of the panels. Most plasma displays are around 100mm thick, so with their wall brackets they should come out even. And the beveled edges of the panels ought to allow ample airflow.

But all that’s just decoration. How does it sound?

That was the surprising thing. I went into that room pictured on the cover with a set of preconceptions about how the sound would be. I didn’t know anything about the diffusers and absorbers at that point, nor even the drivers that were employed. Just that these things were square slabs attached to a wall, and all my experience and theoretical knowledge told me that they would sound two dimensional, coloured, and possibly have a boomy bass end.

That it was so pleasant on the eye did nothing other than strengthen my low expectations.

So of course i was startled when the system was fired up. Driven by Denon’s new AVR-3804 receiver, it delivered in a way it had no right to.

My expectations were quite confounded. The SoundWall sounded – on an absolute scale – excellent. When the location was considered – speaker panels hard up against a wall – it sounded unbelievable!

This SoundWall, when playing back stereo, sounded like decently sized floorstanding loudspeakers, or high-quality largish compact loudspeakers, stand-mounted and sited well clear of room boundaries.

The tonal balance was very good indeed, with clean and crisp cymbals, clear and well-articulated vocals, and an extraordinarily well-extended bottom end. VAF had the view that people seeking this kind of sound system invisibility would probably not want a subwoofer lodged somewhere in a corner, so it designed the speakers to deliver that deep bass. With the program material i listened to, i have no reason to quibble with VAF’s bottom-end specification of 32Hz at -6dB.

The small ports, forward facing as they are, could have been problematic with chuffing, but despite advancing the volume control with bass heavy material, i could detect nothing of the kind. There was a slight forwardness in the mid-bass, perhaps around 80 to 100Hz, but that seemed well controlled and didn’t detract significantly from performance.

All that attests to good bass tuning and driver selection for the location. But what about the other significant problem for close-to-wall speakers placement: imaging?

It must have been the acoustic control panels that did the trick here, because once again the speakers sounded more akin to high-quality freestanding speakers. There was a discernible depth in imaging, and good focus across the sound stage in stereo mode.

The particular installation should have been a problem for surround sound because the rear speakers really were to the rear, rather than to the sides, far away on the back wall. Yet despite this an enveloping surround was produced, with no gaps down the sides of the room.

VERDICT

VAF Research has to be congratulated. It has taken two apparantly irreconcilable design objectives – invisibility and high performance – and not only reconciled them, but produced a result that’s better than many freestanding speaker systems.