Atlantic Technology says the AT-1s use a breakthrough acoustic technology that allows speaker designers to achieve targeted bass performance with smaller drivers, smaller cabinets and lower cost. Called ‘H-PAS’, it’s in the company’s AT-1.
 

After first demonstrating its ‘Hybrid Pressure Acceleration System’ (H-PAS™) speaker technology in 2009 (at CEDIA), US company Atlantic Technology followed up by releasing its AT-1 loudspeakers at the Las Vegas Consumer Electronics Show in January 2010. The CES press release announcing the speakers boasted: ‘H-PAS is a breakthrough acoustic technology that allows speaker designers to achieve targeted bass performance with 50 per cent smaller cabinets, smaller drivers, and lower costs.’ Well, the AT-1 speakers have finally arrived in Australia, and Claver Harper, from local distributor Network Audio Visual, was quick off the mark to send us one of the first pairs for review.

Atlantic-AT-1 LoudspeakersThe Equipment

Having read the press release prior to the speakers arriving, I was a little surprised when they did arrive, because the two cardboard shipping boxes were hardly what I’d call ‘small’! And, when I’d finally unpacked the speakers, screwed on their outrigger feet and conical ‘spikes’, and stood them upright in my listening room, they still weren’t exactly small… though to give them their due, they were the smallest of five pairs of floor-standers currently in the process of being reviewed. In fact, the AT-1 cabinet is 1,041mm high, 227mm wide and 348 mm deep. Given these external dimensions, and the fact that the cabinet is mostly constructed from 19mm MDF, my ‘back of the envelope’ calculation put the internal volume of the AT-1 cabinet at 89-litres, or almost double the 1.6 cubic feet (50-litres) claimed by Atlantic Technology.

However, I think I would have been disappointed if the cabinets had been smaller, because their impressive size means there’s more to admire in the curved side walls, which are finished in a superb, high-gloss ‘metal-flake’ black lacquer paint, the artfully-curved (and magnetically attached) punched black metal speaker grilles, the outwardly curved lower section of the front baffle and the classy glass top plates that finish off the speakers. Make no mistake; Atlantic Technology’s AT-1s are very, very good-looking loudspeakers!

Detaching the metal grilles reveals the driver complement, which is a pair of 133mm (nominal) diameter bass/midrange drivers, mounted above and below a single 28mm tweeter in classic MTM geometry. The bass/midrange drivers are identical, with cones made from graphite-loaded homopolymer (GLH). At the centre of each cone is a black, stiffened fabric dustcap with a conventional ‘dome’ profile, while at the periphery there’s a rubber suspension, again with a conventional profile. Atlantic Technology rates the diameter of these bass/midrange drivers at 133mm. Despite appearances, the driver chassis itself not circular, so my measurements of it returned an overall dimension of 150mm (widest) and 133mm (narrowest), with a mounting hole figure of 139mm and a Thiele/Small diameter of 109mm. This last (most important!) dimension puts the Sd at 94cm² per driver, or 188cm² for the system, meaning that if Atlantic Technology had used just a single driver to deliver bass, instead of two, its ‘nominal’ diameter would have to have been in the order of 170mm to displace the same amount of air. The driver chassis is made from pressed steel and supports a standard-sized, non-vented magnet that’s 28mm deep and 88m in diameter. The design of the soft parts is conventional, with the volume of air underneath the spider being unvented. The drivers are attached to the baffle using cross-head bolts and captive threaded retainers, so they can be easily removed.