October 2012

Atlantic Technology AT-2 H-Pas Speakers
Impressive sounding monitor at a very affordable price.
Review By Ron Nagle

  Atlantic Technology is a relatively small American manufacturer not widely known by many audiophiles. They produce affordable high quality audio speakers and are based in Massachusetts with operation overseen by President and CEO Peter Tribemann. They manufacturer a complete line of surround sound systems for audio/video installations. Indeed, they offer a mix and match line up of speakers including center channel sound bars and subwoofers for a Home Theater system. That may be the reason why they might be overlooked as a source for home stereo systems for audiophiles. Atlantic Technology also manufactures impressive two channel speakers and earlier this year they added two new models of interest.

The first is a floor-standing three-driver speaker called the AT-1. In Addition there is our review subject the AT-2 a stand mounted two-way speaker. Both models use an innovative computer aided acoustic design algorithm. The AT-2 measures 8 7/8" x 15 5/8" x 12 5/8" (HxWxD). It uses a 1 1/8" (28 mm) soft dome tweeter in combination with a 5.25" (128 mm) mid-woofer. The mid woofer cone is constructed with a Graphite Loaded Homopolymer (GLH) material.

Both of these stereo speakers feature an innovative cabinet construction Atlantic Technology refers to as, H-PAS. H-PAS is a Trade Marked term for "Hybrid Pressure Acceleration System". At the front panel just below the drivers, there is a rectangular shaped port. At first sight you might think that this is a classic Bass Reflex enclosure. However, the patented H-PAS system combines elements of several speaker construction concepts. There are in fact elements of acoustic suspension, bass reflex, inverse horn, and transmission line techniques used in the design. It is in fact a very extensive rethink variation of what looks like a Bass Reflex design. It is in fact a complex purely acoustic approach using tuned chambers in the cabinet that enable bass response down to the manufacturer specified, 44 Hz.

Fine Fiddly Finish
At first sight the speaker's construction and finish is way beyond what I had expected. The curved MDF side panels are real cool high gloss black with metal flake highlights. The top, rear, and front surfaces have a very nice black vinyl looking leatherette covering. The perforated black metal grill offers full front coverage and is held in place with neodymium magnets. The back panel has recessed gold plated dual binding posts strapped together with gold plated jumpers. These two sets of binding posts will allow bi-amplification. Therefore, you have the option to drive the AT-2 with two separate power amplifiers.

You could use one amplifier to drive the tweeter for the high frequencies above 2.2 kHz. Then connect the second amplifier to drive the mid woofer and the lower frequencies. There remains one more option. You will find a small toggle switch positioned just above the speaker binding posts. The switch is formally called the "High Frequency Energy Control". This switch has three positions that alter the energy output of the dome tweeter. The center position is marked with a zero that denotes a flat setting. The twelve O'clock switch position is marked only with a plus symbol and at the six O'clock position there is a minus symbol. There is no specification given for the range of this switch adjustment but the effect is clearly audible.

Setup And First Impressions
After unpacking the AT-2 speakers, I placed them on my 24" stands in what would approximate an equilateral triangle eight feet from my listening position. Pointing them exactly straight ahead, for best sound the speaker were spaced 5.5 feet apart in my small room. They face in a parallel alignment to either side of my listening position. My basic imaging test is too gradually move the speakers farther apart until the center image just starts to fade away. One of my big wish list requirements is that I might sit directly in the center of a (hopefully) wide sound stage with the speakers off on either side.

Now with most any speakers this test is pushing things a bit. What I noticed almost immediately was the AT-2 was capable of imaging far off on either side of the center position. Another way to say it is, Lateral sound dispersion and therefore center stage imaging was unusually solid. A closer look at the tweeter provides part of the answer. The tweeter looks like a very standard style soft dome fabric construction. However, on closer inspection the soft dome is mounted at the center of a ring that forms a soft roll surround. The fabric surround increases the sensitivity and dispersion capabilities of the tweeter. In addition, the tweeters front mounting plate with its oval shape helps by providing a reflective surface.

In my humble abode, I had to do a bit of fiddling to get the unusually extended bass to Integrate into my room. The speakers were moved forward five feet away from the back wall. In addition, I used my home made absorptive baffles on either side of the stands to acoustically isolate the speakers from the sidewalls. The next set up adjustment is an option I wish every speaker manufacture would provide, it is the Hi-frequency tweeter control. Its intended purpose is to adjust tweeter to bass spectral balance over a very broad range of 2 kHz up to 20 kHz.

Apparently, it is not a frequency cut or boosts control as I first assumed.  Rather it pads down the tweeters total energy output within its crossover range.  And the effect it has is a wide ranging psychoacoustic phenomenon, in that it seems to reach down and alter the sound of the bass. After some trial and error, I left the switch in the center or flat position. The manufacturers blurb about flat response was spot on. The tweeter control somewhat to my surprise is exceedingly effective at altering overall frequency balance even down to the bass frequencies.

Aural Aspects
Ok, let us listen to some music, for this story, let me source some of my go to reference CDs. Right now, I cannot think of a better recording to illustrate the strengths of the AT-2 than a wonderful version of You Were Always On My Mind by Willy Nelson. This recording is a copy of a copy of a compilation by many different artists circulating among local Audiophiles, the origin of which I know not. It is a wonderfully engineered and detailed studio mix with transient speed and studio ambience that highlights the resolving ability of any speakers. At two minutes and forty seconds into this cut, there is a brief faint sound of a person in the distant background whistling along with the melody. Meanwhile Willy's vocal resides front and center in all his nasal glory amidst the glisten of steel guitar strings. Backup vocals are etched and clearly delineated and recede in layers from the immediate left center stage. In a strange and unexpected way, the metallic reverberation of the guitar strings complements the country twang of Willy's voice.

If you want to test the AT-2 low frequency tonal integration than I can think of no better way than to play Adagio d' Albinoni as performed by Gary Karr and Harmon Lewis. This is my go to bass reference recording because the bass sound should convey the wooden overtones of the instrument. It was originally on a Japanese Firebird label but it may be available via the Cisco Music catalog [GCD8003]. Recorded in a cavernous Japanese cathedral it is a duo of a large sonorous pipe organ and Gary Karr's century's old Amati bass fiddle. The reverberations and echo of the low register organ pipes hold the woofer for a moment on a deep sustained rumble, and the sound is clean and controlled. The resinous wooden bass bowing sighs and breathes a mournful moan that tugs at your heart. The sound is absolutely organic and for a time you forget that it's not flesh and blood calling out to you.

I would like to mention one last recording even though it is not strictly a reference but rather a fun recording I enjoy very much. It is a gathering of famous artists brought together to celebrate the Queen of England on her Golden Jubilee. Recorded live out doors near Buckingham Palace the sound it is clean spacious and dynamic when played through the AT-2. You can find it on Virgin [7243 8 12833 25] and it is called Party At The Palace. Did you ever hope to hear Brian Wilson performing God Only Knows backed by The Royal Academy Of Music Symphony Orchestra? Of course there is much more to commend it, like Rod Stewart, Elton John, Paul McCartney and Eric Clapton to name only some of the talent on this disc, it is wonderful music that is wonder filled!

Conclusions
Let us couch this consideration by using a price to performance ratio; this is most always calculation number one.

First, the tweeter control switch removed almost all of my initial objections. The vast majority of the time the switch remained in the center or flat position. However, I found one or two CDs that caused me to increase the treble balance. If you evaluate the AT-2 retrieval of faint musical details, than it is most certainly excellent. However once again much of the micro-nuance you hear are affected by the setting of the tweeter. This is true because most location clues that arrive at our pinnae are carried by the higher frequencies. If another term could be used to describe the tweeter adjustments and its functionally, it would be as a Presence Control. All things considered, this added flexibility will have to be counted as a definite plus. Now moving down the musical scales to the midrange things can get a bit tricky. Remember the setting of the tweeter affects almost the entire range or more accurately the tonal voicing of the speaker. Listening with the switch in the center position the mid range carries the music and the sound is slightly warm. On voice recordings that is absolutely the way to go.

Consider that the extended low frequency response toward mid and deep bass could depend on your setup and your room. As a matter of fact, in my listening room frequencies below 55 Hz start to resonate in my room. Because of this I never push up the volume beyond what would be considered normal listening levels. Certainly they have deep bass, but I don't believe an audiophile should or would back these speakers flat up against a wall or listen with them in a corner placement. During this evaluation, I never listened with the tweeter set at the minus/cut position. If there was an overall characterization of the sound of the deep base it would have to include the words warm and round.

Bottom line, there came a time when I stopped listening for flaws and I just sat and listened to the music. There may be a better two-way speakers out there, but they would have to cost far more than the $1800 AT-2. Congratulations Atlantic Technology you have managed to tear down another long-standing barrier to affordable sound.

Semper Hi-Fi

Specifications
Type: Two-way monitor using H-PAS Hybrid Pressure Acceleration System
Drivers: 5" woofer long-excursion with GLH cone
           1 1⁄8" low-resonance soft dome tweeter with 4mm oversize long-throw surround
Frequency Response: 41 Hz to 20 kHz (+/-3dB)
Nominal Impedance: 6 Ohms
Crossover Frequency: 2.2 kHz
Crossover Type: Parallel, 2nd-order LP, 3rd-order HP
Sensitivity: 88dB/W/m
Recommended Amplifier Power: 20 to 150 Watts RMS
Dimensions: 8 7⁄8 x 15 5⁄8 x 12 5⁄8" (WxHxD)
Weight: 23 lbs each
Price: $1800

Company Information
Atlantic Technology U.S. A. 
343 Vanderbilt Avenue 
Norwood, MA 02062

Voice: (781) 762-6300
Website: www.AtlanticTechnology.com