Atlantic Technology System 250 home theater loudspeaker system
When something called "high fidelity" assumed fad status during the 1950s, many manufacturers climbed on board by the simple expedient of adorning their last year's product with a high fidelity label. The Home Theater bandwagon is a little harder to jump on, because loudspeakers for use with television sets require something "ordinary" stereo speakers don't: magnetic shielding (or, more accurately, magnetic cancellation). Without it, placing the speakers within a few feet of a large-screen set does psychedelic-type things to the color (footnote 1). However, adding magnetic shielding, usually in the form of a second magnet glued to the rear of each loudspeaker's motor magnet, is the only thing that some loudspeaker manufacturers change before slapping a Home Theater label on last year's stereo speakers.
Atlantic Technology's 250 system, on the other hand, actually looks as if it was designed from the ground up to address all the requirements of a system intended for listening to movie soundtracks, while retaining as many as possible of the things deemed important by high-end audiophiles. That's a tough order. (In fact, there are many who claim that the two are inimicalthat the best soundtrack reproduction can only be obtained to the detriment of music reproduction, and vice versa. I think I disagree, but I won't go into that now.) So, how close does the System 250 come to those lofty goals? Read on.
The 250 System
The six-piece 250 system consists of a pair of satellite front left and right speakers, a compact, low-profile center speaker, two surround arrays, and a powered-subwoofer module that does double duty as a stereo power amplifier for the whole system and as a dedicated subwoofer driver.
The 251LR left and right speakers are slim two-way units with a dome tweeter centered between a vertical pair of 4" polypropylene-cone woofers. This arrangement delivers wide dispersion through the tweeter's range, a narrower vertical pattern through the woofer's upper range, and an increasingly omnidirectional pattern toward the low end. The effect sort of resembles the controlled vertical-dispersion pattern called for by the THX standard.
The 253C center channel is a similar array, but arranged horizontally for unobtrusive placement on top of or in front of a video monitor. It features two "timbre-adjusting" controls, which are essentially midrange and treble tone controls. Because the center speaker will be placed in close proximity to the monitoreven on top of itit's much more susceptible to unpredictable cancellation effects than the stand-mounted left and right speakers, which operate essentially in a free field. The difference is conspicuously audible when you listen to the circulating pink-noise test signal generated by Dolby Pro Logic surround decoders, because you get side-by-side A/B comparisons between the sides and center with each circle. The 253C's controls don't completely eliminate the difference, but I found they were able to reduce it to quite an astonishing degree. A unique feature, I believe, and a very useful one.
The surround speakers, like the lefts and rights, are also sort-of-THX; but this time it's the midrange and higher frequencies that are bidirectional and the woofer that's not. The idea of a dipolar surround is that, when it's placed to the side of the listening area, it directs the surround signal along the side walls of the room, but places the listener in the dipole's cancellation "null" zone, so that he hears the surround in the room more loudly than he heard the speaker directly. The effect is that the speaker seems to vanish. (The first time I heard this system, in a darkened room at Hi-Fi '94, last year's Stereophile High-End Hi-Fi Show in Miami, I was completely unable to locate where the surrounds were. They were about 5' from where I was sitting.)
The 252PBM powered bass module is a neat idea. Its three built-in 40W amplifiers can be used separately to drive two surrounds and the subwoofer, with an external amplifier or receiver driving the front speakers; or you can use external amps for all the upper-range speakers (including the center speaker). This offers a really painless way to upgrade from an existing, modestly priced stereo system to basic surround, and then to a full-blown Home Theater surround system, in two steps. I opted to skip the first step.
I put the satellite left and right speakers on their optional stands, about 2' in front and slightly flanking the edges of a 31" monitor screenso as to yield an included angle from the listening seat of about 70°. I placed the center channel on the midpoint of the arc between them, right on top of the monitor, and the surrounds directly at the sides of the listening area, as recommendedeach was about 7' from the center of the listening area. The subwoofer was a couple of feet from the front wall, offset by roughly one-third the width of the listening room, to minimize standing-wave response irregularities.
I used the CP-3's Dolby Pro Logic test signal to set the output levels of all channels to 75dB SPL at the listening position. (Radio Shack's el cheapo sound-pressurelevel meter is ideal for this.) Much to my surprise, the CP-3's output levels needed hardly any tweaking at allthe front channels were precisely at 75dB level with my Parasound amplifier's input level controls wide open.
Sound When I first fired this system up, I had just concluded a long love affair with Fosgate/Audionics's pricey home-THX system (footnote 2). I was quite prepared to be singularly unimpressed with the Atlantic Technology.
I was definitely not unimpressed. This puny-looking system made such a big sound in my room that it was almost laughable. As usual, it was necessary to tweak the surround level to a few dB over what the measurement indicated, and the bass also needed some lifting (see below); but after I did that, I spent weeks almost dizzy with astonishment at what this system could do.
For example, it occasionally shook the floor with bass from noisy film soundtracks, yet it never boomed or sounded as if the low end was getting away from it. It had remarkable speech intelligibility, yet it didn't squawk, spit, or sizzle on vocal sibilants. It had more than passable definition and inner detail, an amazing degree of invisibility (with the lights off, I could not localize any of the speakers, except from memory), and a surprising degree of freedom from midrange colorations.
And it could play well into the 90dBs without pooping out on heavy bass. That's not THX-loud, but it's more than enough to impel your neighbors to pound on your apartment walls.
Unfortunately, the Atlantic Technology system wasn't perfect. (Perfection costs more!) Its most serious shortcoming, as far as I'm concerned, was its lack ofif you'll excuse the languageballs. Because of a weakness through the lower midrange, it lacked the stentorian authority and power that symphonic music, rock, and soundtracks need to make you sit up and take notice. Bass trombone, for instance, sounded emasculated and blat-free, and the delicious dirtiness of a rock guitar sounded more like a spinster trying to talk naughty. It didn't quite come off. Then there's a little matter of the midbass.
I mentioned the need to raise the subwoofer level a few dB over its calibration setting. This, it turned out, was because it was second-guessing the subwoofer output from the Lexicon. The processor's sub-out has an 80Hz crossover, which is the de facto (and THX) standard for Home Theater. But the 252PBM also has a low-pass input filter, and it's undefeatable. As a result, the range of frequencies around 80Hz was being attenuated by about 3dB too much.
During system calibration, the SPL meter was measuring the subwoofer's maximum output across its passband, not its average level in each frequency band. A depression in the 80Hz region would not register, therefore, but as a lot of musical bass information lies in this range, the subwoofer sounded as if it wasn't set high enough. Jacking it up by 1.5dB added the necessary midbass body without making the 40Hz range too prominent. But it would be nice if you could switch out the 252's crossover and not have to compromise the bass. [Either that, or Atlantic Technology should make it more clear that the system's owners should not use their Home Theater receiver's or processor's dedicated subwoofer outputs.Ed.]
What did the Atlantic Technology 250 system do best? Music or soundtracks? This was, as always, a difficult call, because it's so hard to know what most recordings really sound like. I will say that it didn't sound as gorgeously sumptuous on music as some audiophiles demand, and its deficiencies were exacerbated by listening without the distraction of any accompanying picture. But the Atlantic Technology system's reproduction of my own recordings elicited a strong recognition response, suggesting that this system is more "accurate" than "musical."
Everything considered, I find the Atlantic Technology 250 system's price to be almost beyond belief. The 250 system delivered a lot more than $1500 worth of surround-sound quality. A fabulous buy.
Footnote 1: For the technically curious, what it does is redirect the picture-tube's electron beams, causing them to strike the wrong phosphor dots. Thus, the green gun hits the red and blue dots, the red gun hits the green and blue dots, and so on. [If extreme, the tube's shadow mask could become magnetized, rendering the discoloration permanent, even though a turn-on degaussing sweep is supposed to eliminate this problem.Ed.]
Footnote 2: Harman has discontinued its Fosgate/Audionics brand, replacing the products with ones branded "Citation."Ed.