Atlantic Technology 3.1 HSB Soundbase Review

PRICE $799

Impressive bass without external sub
Smooth, unfussy top end
Suitable for TVs up to 100 pounds
Passive design requires use of an AV receiver

Atlantic Technology’s 3.1 HSB uses H-PAS bass technology to deliver real bass response along with enviable smoothness and dynamics.

Visualize, if you will, a home theater system with a flat-panel TV and 5.1-channel surround sound. For many readers, this is nirvana. For others, it’s too much stuff—a TV, three speakers in front, two surrounds, and a subwoofer. How do you reduce the intrusion into the room? Wall-mounting the TV is a no-brainer. Now imagine that the three front speakers have disappeared, along with that pesky sub. What’s left, you’re probably thinking, is some kind of typical soundbase or bar. It offers bass hardly worthy of the name, fake surround, and a fraction of the features of a receiver-based system. For this Atlantic Technology model, you got the first part right—the 3.1 HSB is a soundbase—but the rest is wrong.

What you’re looking at are the basic elements for a true 5.1-channel surround system, with the 3.1 HSB handling the three front channels and the subwoofer’s duties. Yes, this system still relies on external surround speakers (if such things matter to you; I’d suggest on-wall or high-performance in-wall/in-ceiling models to keep them off the floor and nearly invisible). And yes, this hybrid passive soundbase requires an AV receiver for the front channels; only the sub section is self-powered. But along with a dozen growing pains, having a full-featured AVR will ultimately bring a thousand joys not normally associated with a soundbar: network audio, wireless fun, app control, lossless surround, room correction, the works.

The pièce de résistance is the 3.1 HSB’s ingenious H-PAS cabinet design, which enables it to produce enough bass to make a separate subwoofer unnecessary in many rooms (mine included). Now that you’ve eliminated the last large, heavy box, you can practically hear the floor breathing a sigh of relief. More room for rampaging toddlers and dogs.

Three Point One
Nearly 3 feet wide, the HSB can hold TV weights up to 100 pounds and is suitable for screens up to 65 inches. (Its top panel measures in at a generous 35.75 x 16.75 inches, making an ample platform for the TV’s pedestal or legs, though it’s always a good idea to measure.) On the back are a rectangular port and three pair of extremely sturdy all-metal spring-loaded binding posts. I appreciated that the holes were large enough for my speaker cable’s banana plugs, though that’s probably just a reviewer thing. There’s an RCA input for the built-in subwoofer; you also get the controls usually associated with a sub, including level, crossover, and phase.

On the front is a cloth grille. It’s detachable, which is unusual for a soundbase, and the frame is impressively sturdy, with relatively little flexing as you pull it off. That enables you to inspect the three 0.75-inch soft-dome tweeters and six 3.5-inch composite paper cone woofers, arranged in a horizontal array of woofer/tweeter/woofer for each of the three front channels. While I’d usually worry about uneven off-axis response caused by sum-and-cancellation effects in drivers so arranged, they’re physically close enough to one another to minimize the deleterious aspects of this interaction.

All of that is visible, at least to the curious. So is the 6.5-inch bass-driver grille on the bottom of the enclosure, with the driver firing downward into the 0.75-inch space created by the vibration-damping rubber feet. But what makes the 3.1 HSB special is what you can’t see: an elaborate system of chambers inside the enclosure that enables the bass driver to create, with less distortion, more bass than the cabinet’s size would naturally allow. Atlantic calls it H-PAS, which stands for hybrid pressure acceleration system. As described on Atlantic’s Website: “Employing a unique cabinet design, the elements of the different speaker technologies are cascaded one to another in such a manner as to pressurize and accelerate the very lowest-frequency back waves as they travel through the cabinet.”

The result is what Atlantic claims to be frequency response down to 35 hertz –3 decibels. If our measurements confirm it, that would be some serious bass extension. The six front woofers’ high-pass crossover to the bottom-firing bass driver is handled by the crossover in your receiver or surround processor. The manual recommends a setting of 125 Hz. The 3.1 HSB has a nominal impedance of 6 ohms and a fairly average sensitivity rating of 89 dB. Recommended amp power is 10 to 150 watts RMS, well within the range of most receivers, even less expensive ones. But if you bought a step-up receiver for improved dynamics, you’ll get your money’s worth.

H-PAS is the brainchild of speaker designer Phil Clements (of Solus/Clements) in collaboration with Atlantic Technology personnel. It was Clements who dreamed up an elaborate blend of bass reflex, inverted horn, and transmission line designs. Since then, Atlantic has spun out H-PAS to license the technology to other manufacturers and speaker brands. Boaz Shalev, Atlantic’s chief technology officer, applies a massive amount of computer finite element analysis to fine-tune and customize every H-PAS speaker design. For a detailed look at how H-PAS works, I defer to my colleague Daniel Kumin, who explains it all in his review of the AT-1 tower speakers. In the five years since H-PAS made its debut with the AT-1 ($1,500/pair on AT’s online store), also reviewed by Tom Norton in February 2011, it has been joined by only three additional products: the AT-2 monitor ($900/each), which I reviewed in April 2012; the PB-235 active soundbar (now $799 at AT’s store) reviewed by Darryl Wilkinson in October 2012; and now the hybrid passive 3.1 HSB soundbase.

Associated equipment for this review included a Pioneer Elite VSX-53 AV receiver, Oppo BDP-83SE universal disc player, Panasonic DMP-BD87 Blu-ray player (for streaming), and Paradigm Reference Studio 20 v.4s used as surrounds. All movies were on Blu-ray Disc with DTS-HD Master Audio soundtracks.

Chip Off the Old Block
The 3.1 HSB is a smooth operator. Its highs and upper mids steadfastly avoid brightness, glare, and grit. While not especially airy, it can be counted on not to emphasize irritants in content or source components. That might be merciful in rooms with a lot of hard reflective surfaces, though I got good results in a room with heavy carpeting and side-wall clutter.

Atlantic Technology
(781) 762-6300