High frequencies were accurately portrayed, so that the harmonics were correctly structured, but the sound was pleasantly ‘rounded’ which I initially put down to the use of a soft fabric dome, rather than a metallic one. However, in the end I decided that it was more likely that I was hearing a very slight attenuation of the extreme highs—not enough to lose the lovely ‘air’ around the high frequencies that was always apparent, but just enough to give that rounded sound. Then I remembered that I had completely forgotten about the tweeter level switches and when I checked, both were in the –1dB position. A few hours of playing with various settings revealed that I was happiest with the 0dB setting, though on some CDs +1dB was definitely the go. I would, however, rule out the –1dB setting entirely unless your room is supremely acoustically bright!

Bass response was very good, with various of my deep bass CDs proving that it extended down to at least 31Hz at almost reference level. However, my CD of single piano notes showed that B0 (30.8Hz) is really as low as it goes, because the A# underneath it was ‘way lower in level, and then the A natural even lower in level again. However, although bass extension was excellent, and the detailing of solo bass lines was outstanding, I found the ‘impact’ level of the transient bass notes—while it was OK at lower listening levels—was somewhat less satisfying at higher sound pressure levels, and most noticeably if there was also a dense layer of additional musical information going on at the same time, particularly at low frequencies, but also in the upper bass and lower midrange. In practical terms, this mostly meant that it was only large-scale orchestral works that had me reducing the volume to retain clarity and balance but, though rarely, it also sometimes arose with jazz and rock CDs. And although the AT-1s can certainly be played loud—very loud, in fact!—sustained high-volume operation saw some loss in dynamics after a few hours.

Conclusion

After hearing the AT-1s at CES, Stereophile Editor John Atkinson told Peter Tribeman, who was demoing them, that if he could get them onto the North American market at less than US$2,500/pair, he’d ‘have a hit on your hands.’ As it happens, Tribeman did manage to get them onto the US market at less than that price (a greenback less, to be specific). Here in Australia, their recommended retail price sees them competing head-to-head with a large number of similarly-sized, equally highly-credentialed floor-standing speakers that can deliver as much—or more—deep bass, thanks to the use of more and/or larger drivers. All of which will make your buying decision considerably more difficult, but when push comes to shove, I would not be at all surprised if the excellent sound quality, impressive bass and good looks of Atlantic Technologies’ AT-1 get them across the line in your listening sessions… and most particularly if your friendly local dealer has sweetened the pot by shaving some dollars off the RRP! # greg borrowman

Who’s Behind Atlantic Technology?

Atlantic Technology is owned and operated by Peter Tribeman, who has an impressive track record in audio. After founding a company called Audio Pulse in 1975 (the company developed one of the first consumer-oriented time delay systems) he moved on to become president of NAD (USA) in 1980, in which position he famously arranged what is widely regarded as the first public demonstration of a Dolby multi-channel home theatre system at the 1982 Chicago CES. He left NAD in 1989 to found Atlantic Technology, though it was not officially incorporated as a company until 1992. Despite still owning and operating Atlantic Technology, Tribeman and six other principals formed a consortium to found another company, Outlaw Audio, in 1989, in order to manufacture electronics products for direct sale to consumers via the Internet. Two years after the company was founded, GoodSound’s Srajan Ebaen asked Tribeman why he thought Outlaw Audio’s business model would be successful. Tribeman told him: ‘Our seven Outlaw principals, myself included, are experts in failure. We all have worked in this industry for decades. We’ve designed, manufactured and sold every product in the book. We’ve learned what works and what doesn’t. We know about engineering and manufacturing. During our combined 120 years of experience, we’ve enjoyed some successes, but we’ve also committed many mistakes—hopefully we’ve learned a bit from those. We feel that we now have the right template to offer really successful products.’ In the almost two decades Tribeman has owned Atlantic Technology, he has certainly demonstrated a knack for hiring talented people to work for him. So far, Atlantic Technology has used the services of a number of famous loudspeaker designers, including Vance Dickason (author of the Loudspeaker Design Cookbook), Martin J. King (the world’s foremost authority on quarter-wave transmission lines) and Phil Clements (founder of Solus/Clements Loudspeakers). The company is headquartered at 343 Vanderbilt Avenue, Norwood, Massachusetts and has recently been granted trademark protection for the use of the letters ‘H-PAS’ in relation to loudspeaker sales, hence the ‘TM’ appearing after them whenever the letters H-PAS appear in Atlantic Technology’s literature. G.B.

Behind H-PAS Technology

While I have no doubt at all that the particular enclosure design that is used in Atlantic Technology’s AT-1 is very effective at delivering good bass, I do harbour doubts as to whether the cabinet design is either new or innovative. Indeed the internal layout of the cabinet looked to me to be practically identical to one shown in a long-expired patent granted to Philip R. Clements and Donald R Smith more than 30 years ago (US Patent #4373606). And although one US-based reviewer (Daniel Kumin) says the technology in the AT-1 was described to him by Atlantic Technology’s team as ‘combining elements of acoustic suspension, inverse horn and transmission line designs’ (SoundandVision October 2010), the AT-1’s cabinet would seem to me to be just a small-volume bass reflex cabinet containing two small bass/midrange drivers. Such a small volume enclosure would require a long vent to tune down near its claimed low-frequency limit, and such a vent is indeed provided inside the AT-1 enclosure, running down the inside of the rear wall. Using such a long vent has several well-documented disadvantages, which include that it magnifies driver distortions, can result in port noise and, perhaps most significantly, that it puts a ‘suck-out’ in the direct frequency response radiated forward by the bass driver(s). So what would be the ‘classic’ acoustical engineering solution to these problems, using existing knowledge? According to the expert acoustician I consulted, these effects could be eliminated, in his words: ‘…by another pipe, or stub, acoustically coupled to the vent e.g. by placing its opening close to the opening of the first one. This second organ pipe, stopped this time at one end, is a quarter wavelength stub tuned to the frequency of the first and is thus approximately (not exactly, due to end effects) half the length of the vent. This chamber need not, of course, be a λ/4 stopped pipe. It could be a Helmholz resonator, another small vented box, tuned to the vent’s λ/2 frequency.’

And, looking inside the cabinet of our review sample of the AT-1, this is exactly what I found—a separate vented chamber, with its opening close to that of the main vent that runs down the inside of the rear wall and exits on the front baffle at the base.G.B.

Readers interested in a full technical appraisal of the performance of the Atlantic Technology AT-1 Loudspeakers should download the laboratory report. Readers should note that the results mentioned in the report, tabulated in performance charts and/or displayed using graphs and/or photographs should be construed as applying only to the specific sample tested.

Atlantic Technology AT-1 Loudspeakers

Brand: Atlantic Technology
Model: AT-1
Category: Floorstanding Loudspeakers
RRP: $4,500
Warranty: Five Years
Distributor: Network Audio Visual Pty Ltd
Address: Unit 6B, 3–9 Kenneth Road