Avantgarde Acoustic UNO XD Loudspeaker

hfnoutstandingClassical horns do not come any more colourful, or compelling, than this 'entry-level' floorstander

Hi-fi can be such a confusing passion, with so many products to explore in the quest for better sound, but enthusiasts often start by upgrading their loudspeakers, as they're where the greatest subjective differences are typically to be found. Most will begin with conventional box speakers, but many then progress to more left-field approaches – the most striking being 'horns'.

German manufacturer Avantgarde Acoustic specialises in precisely this genre, offering a range of horn-loaded speakers that spans relatively compact and room-friendly products like the Zero TA XD to the huge, crazily-proportioned Trio Classico XD. Sitting towards the lower end of the company's range is the £21,500 UNO XD that you see here – effectively the brand's entry-level to its series of 'proper' horns.

No Tears
This loudspeaker, one might say, is 'a horn design without tears'. How so? Well the breed is often wilfully eccentric – whacky, even – but the UNO XD is quite conventional, in some respects at least, employing modern technology to make a hybrid of passive horn-loaded treble and midrange drivers with active bass units.

Given that the acoustic amplification of a horn greatly increases speaker sensitivity, Avantgarde ramps up the bass to match by using an active sub system featuring twin-powered woofers. In practice it's rather more than a 'sub' because these bass drivers work right up to the 290Hz crossover with the midrange horn.

This system obviates the need for the vast cabinets that would otherwise be required to accommodate huge bass units. This is a complex and potentially risky approach because successfully mating one 'style' of driver to any other isn't always easy, and that goes double for marrying horn-loaded passive treble and mids to non-horn-loaded active woofers. To help things along, the UNO XD's active bass system uses highly configurable DSP, not only to optimally pair the drivers themselves, but also to let owners tailor the bass response to particular room acoustics and/or tastes. Volume settings, delay time, high and low pass filters and up to ten parametric equalisation curves may be programmed via a connected Mac or PC.

Screw-Fit Horns
Unpacked but not assembled, this loudspeaker looks not unlike a conventional box design – it has no fancy radiused edges and the cabinetwork seems outwardly pretty standard, albeit reassuringly rugged. There's even a detachable front grille, just as you would see on a heavyweight floorstander. Look closer however, and you'll see threaded recesses for the two ABS pressure-moulded spherical horns, around the edges of both treble and midrange units.


Both the midrange and treble horns are shipped separately and screw into place atop the two dome drivers. The top horn is both supported and isolated from the front baffle via a thick, tubular rubber gasket, visible here

Boxed separately, the two horns take barely a minute to gently screw in, the larger mid horn sealed into the cabinet by a thick rubber gasket. As you would expect, both drivers are bespoke. The midrange is a 127mm soft mesh type and its partnering horn is a 500mm diameter, 280mm long affair. The tweeter is a 25mm mylar dome with a 130mm horn that's 65mm long. The bass units feature 250mm paper cones with ferrite magnets, each driven by a 500W Class D power amplifier, while the DSP takes care of the (active) crossover.


While the front is certainly eye-catching, the 'business end' is at the rear where the mid/treble drivers are hooked up via a single 4mm cable input and the active bass driven either via a line-level XLR input or, preferably, a second set of high-level 4mm speaker connections. The DSP options can then be configured via a small backlit LCD panel, or remotely via LAN or USB connections.

The main speaker cabinet sits on a special cast aluminium frame base with four very substantial, height-adjustable spikes. Avantgarde also makes great play of the UNO XD's multiple finish options: the 30mm-thick MDF cabinet comes in White Satin, Black Satin, Tiger Rosewood and Zebrano finishes while the polished and lacquered horns come in no fewer than 11 colours – including the striking 'Shiny Citrine Orange' you see here.

Avantgarde Acoustic Lautsprechersysteme GmbH
Supplied by: Padood Ltd, Cambridge, UK
01223 653199