Atlantic Technologies AT-1
I know this isn't a new speaker, but a very interesting design that hasn't received a lot of talk. It appears to be an MTM back-loaded horn, which is a popular design in the DIY world, but I can't find another example of it commercially. I bet they sound pretty good with a claimed usable bass range of 29Hz, all in a fairly small cabinet thanks to good speaker design and physics!
Would love to personally hear them as Stereophile gave them a good review, but just a heads up to anyone looking for something different.
http://www.atlantictechnology.com/default.asp?NodeId=159
Would love to personally hear them as Stereophile gave them a good review, but just a heads up to anyone looking for something different.
http://www.atlantictechnology.com/default.asp?NodeId=159
Post edited by zingo on
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Interesting driver and crossover design notes from a review in Stereophile:
A benefit of the H-PAS topology is that it allows the designer to use smaller, quicker woofers without sacrificing low-bass extension. The AT-1's –3dB bass-rolloff point is specified at a low 29Hz—pretty darned good for a pair of 5.25" cones. The speaker also boasts a sensitivity of 89dB, which is nearly unheard of for small drivers capable of such low bass.
The AT-1's woofers are crossed over to its 1.1" silk-dome tweeter at 2kHz, the tweeter seeing a third-order slope and the woofer a second-order handoff. While many two-way designs cross over at higher frequencies, the AT-1's 2kHz crossover ensures a more even dispersion pattern at the top of the woofers' passband and better integration with the tweeter. However, the lower the crossover frequency, the more energy a small tweeter is asked to produce, and the greater chance it has of overheating or running out of excursion capability.
To address these problems, Atlantic has modified the AT-1's tweeter in some important ways. Steve Feinstein: "The tweeter's diaphragm breathes into a rear chamber. This lowers the tweeter's resonance from around 1800Hz to about 900Hz. Next, the entire rear chamber is made from drawn aluminum, which acts as one huge heatsink with lots of surface area, to cool the tweeter really well. Finally, the tweeter's surround is a full 4mm [wide], which is akin to a small woofer having one of those really big surrounds. It lets the tweeter have good, long excursion for low distortion, with no danger of mechanical mishap." The tweeter is also connected to a three-way switch on the rear of the AT-1 that controls its output level through a simple resistive network. The "+" position raises the tweeter's entire range of operation (2–20kHz) 1.8dB from the center position; the "–" switch lowers it by 1.5dB.
