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Reviewer: Paul Candy
Source: Rotel RCD-971 as transport, Audio Zone DAC-1, Zero One Mercury CD/HD Player [in for review], Pro-Ject RPM 5 turntable, Pro-Ject Speed Box, Ortofon Rondo Blue cartridge.
Preamp/Integrated: Manley Labs Shrimp, Audio Zone AMP-1, Blue Circle BmPH [in for review], Pro-Ject Tube Box phono stage.
Amp: Manley Labs Mahi monoblocks.
Speakers: Green Mountain Audio Callisto (on sand-filled Skylan stands), Hornshoppe Horns, (2) REL Q108 Mk II subwoofers.
Cables: Acoustic Zen, DH Labs, Audio Magic Clairvoyant 4D [on loan], SilverFi cable loom [in for review], Stereovox XV2 digital.
Power Cables: Audience, GutWire, Harmonic Technology, DH Labs.
Stands: Grand Prix Audio Monaco four-tier rack.
Powerline conditioning: BPT Pure Power Center w/Wattgate 381 outlets, Bybee Quantum Purifiers and ERS cloth, GutWire MaxCon, Blue Circle BC86, Blue Circle BC6000 [in for review].
Sundry accessories: Grand Prix Audio APEX footers, Herbie's Way Excellent Turntable Mat, Herbie's Black Hole CD Mat, Isoclean fuses, Walker Audio SST contact enhancer, Nanotech Intron 8500 CD fluid, Audio Magic/Quantum Physics Noise Disruptors, dedicated AC line with Wattgate 381 outlet, Echo Busters acoustic room treatments.
Room size: 11x18x8, long wall setup, hardwood floors with large area rug.
Review component retail: $9995/pr in cherry finish. Other hardwoods are available at additional cost.
Back in April 2005, I reviewed and subsequently purchased Green Mountain Audio's stand-mounted 2-way Callisto. Their naturalness of presentation, imaging and coherence was beyond reproach at their price and I haven't been tempted to part with them at all. Last summer I had the pleasure of a close encounter with Green Mountain Audio's upscale Calypso 3-way at the home of GMA retailer George Taylor of Entracte Audio. I was certainly intrigued and keen to obtain a pair for review. While it took some time for the planets to align, George was able to free up a fully run-in pair and deliver them in person. Tagging along was Blue Circle's Gilbert Yeung who also dropped off his BmPH integrated for review. I had heard this combination at George's and was impressed. There certainly seemed to be some synergy at work.


Like the Callisto, the Calypso is constructed of Q-stone; a composite concoction of fine marble dust suspended in a polymer that results in a speaker cabinet with a very low Q i.e. a material's tendency to vibrate. As with all GMA loudspeakers, the Calypso is a time-coherent design. In conjunction with a 1st order crossover, the unusual cabinet shape time-aligns the acoustic center of each driver to produce a coherent waveform i.e. the output of each driver will reach the listener's ear simultaneously and not staggered across time as with other multi-driver speaker designs.


GMA designer Roy Johnson fired me off a brief technical description: "The Calypso uses an 8-inch woofer with a cone made of non-woven Nomex fibers and a cast-aluminum frame having an aerodynamic profile. The woofer's suspension has unusually high compliance, using a thin synthetic SBR rubber surround and a fully-vented, large-diameter flat spider. For low distortion, shorting rings surround the vented 33mm-diameter Kapton voice coil.


"The woofer is mounted into our Q-Stone cast composite shaped for minimum diffraction. This Q-Stone casting is mounted onto the top of an MDF column, featuring what we call a 'Golden-Ratio Baffle' inside. Three chambers are created, with the upper one being the Q-Stone shape behind the woofer. The arrangement and proportion of these chambers prevents the midbass resonances common to long, slender columns but with no effect on the ability of both the woofer and port to drive the entire air volume without resistive loss for the lowest bass. The woofer column is 'twisted' at a 45-degree angle relative to the plane of the woofer. This reduces reflections off the front (as there is no 'front') sent to listeners and scatters others that normally occur between the room walls and the cabinet sides. The large, 3-inch diameter bass port is aerodynamically shaped and tuned to 42Hz. It's located at a golden-ratio position, partway up the black column, on the inboard-rear panel of each cabinet. We recommend the speakers be L-R swapped for a large room, placing the ports on the outboard rear sides.
"The midrange driver is a 4.5-inch unit with a sandwich-cone of epoxy-laminated Kevlar skins over a honeycomb core of Nomex, and has a carbon-fiber/ABS chassis with a vented, high-power voice coil. This driver is mounted into a Q-Stone enclosure of multiple layers, inside of which lies an 18-inch long, felt-and-fiberglass labyrinth.


This attenuates mid and high frequencies while passing the lowest range tones out the back through a two-stage resistive vent. This resistive vent, also used in our Continuum 3, prevents the mid driver from developing its natural low-frequency resonance that would otherwise affect the simple, first-order crossover's operation.

"The tweeter is a compact double-neodymium-magnet design made in the USA. It has a 28mm linen dome, hand-coated with polymer and backed with a large rear chamber. The voice coil is wound with hex-profile copper-clad aluminum wire onto a high-strength aluminum-alloy former. It is ferrofluid-cooled with a moving mass of just 0.46 grams. The unit is encased in a cast marble chamber and mechanically damped. Under the grille foam, small strips of wool felt are embedded in the Q-Stone to prevent diffraction from the edges of its enclosure and to cast an acoustic shadow down onto the mid driver and woofer.

"The crossovers are, of course, 1st-order designs electrically and acoustically, at 350 and 3000Hz. Sensitivity is 89dB and impedance is 4.75 Ohms, +/- 0.75 Ohms, from 150Hz to 20 kHz. Phase shift is +/- 2 degrees from 200Hz to 8 kHz. The Calypso is 51 inches high and 11.25 inches square on the column. The base itself is 13.5 inches square. Due to Q-Stone's density, a Calypso weighs in at 110 lbs. The outer finish is a black Texture-Kote with solid-hardwood panels providing additional damping. Several types of hardwood are available; hand-dyed lacquered cherry is standard. Bubinga, Cocobolo, quilted Maple, American Walnut and Bolivian rosewood are also available. Speaker cable connection is via a pair of direct-gold-plated, oxygen-free copper binding posts on the bottom of the cabinet. Four adjustable point cone feet are included."

The tweeter and midrange modules are shipped separately and require assembly. This is where you'll need a second pair of hands. While one person holds a module, the other connects the color-coded signal wires and then the module attaches to a pair of felt-lined metal tracks on the driver module below via a pair of long Allen bolts. Due to the height of the Calypso and the variability in listening positions, the tweeter and midrange modules are adjustable to achieve driver time alignment. Loosen the bolts on each module and slide them back and forth. The excellent manual offers detailed instructions on optimal setup.

While the Calypso ships with a neat tool called EarSticks to ensure the drivers are properly aligned to the listening position, I tried this by ear first. I played some simple acoustic music and moved each driver back and forth slightly until I was satisfied that the sound was correct. If I moved the tweeter modules too far forward, the treble became a little too bright and the leading edges of notes became too sharp and forward. Pushing it too far back, the reverse was evident. It was easy to notice when the drivers were not optimally aligned. When I checked my final driver positions with a tape measure and the enclosed EarSticks, I found that I was off by about 1/8" on the tweeter modules. I was rather pleased with myself at that result. When I shifted the tweeter modules back 1/8", I noted a slight improvement in image focus. This procedure only took a few minutes and is a lot easier than it looks. Just trust your ears.

The build quality and attention to detail of the Calypsos was excellent. Frankly, I was astonished considering the price. Consider that each cabinet component requires a separate mold for the marble dust/polymer mix. This is not a design that can be easily mass-produced on an assembly line in a few hours.


The Calypso's unique appearance will be controversial. I liked the rounded edges, Bolivian Rosewood side panels and overall shape which I thought gave the speaker a pleasing organic appearance. My wife also found them attractive and a welcome alternative to the usual rectangular shape of most speakers. The Calypsos are certainly more attractive than some of Roy's early designs. The discontinued Continuum 1 was so eye hostile, it surely must have fallen out of the ugly tree and hit every branch on the way down. Only the visually challenged could appreciate that speaker.

The theory behind time and phase coherence can be difficult to grasp and I admit to not fully understanding the complex math behind it myself. I'll leave the number crunching for folks like Roy and instead offer this simple explanation. Phase coherence means that the peaks and valleys of the same sine wave from two drivers all line up at your ear. Make those two sine waves start and stop at the same instant and you'll have time coherence. Since all the peaks and valleys are now in phase, this time coherent loudspeaker is also phase coherent. Why is this important? Because everything in music is about beginnings and endings, sudden transitions, quick subtle inflections and rhythmic pulses. These occur because of the passage of time and according to Roy, "when timing is preserved instead of letting drivers smear over each other i.e. coming on too soon or lagging behind, you will hear more, feel more and play more music". My experience over the last couple of years suggests that Roy is right on the money.


For further discourse on the subject, point your browser to Roy Johnson's extensive comments at the end of my original Callisto review plus Srajan's review of the now discontinued Continuum 3 and this lively thread and thread on Audiogon. Perform a little online research, track down a pair of time-coherent speakers for audition and decide for yourself.

Partnering components during the review period included Zero One's Mercury HD/CD player, my Pro-Ject/Ortofon analog front end, Manley Labs amplification and Blue Circle's BmPH integrated. Since the Calypso's binding posts are underneath the cabinet, banana terminated speaker cables are a no-no. Use spades or bare wire. While I achieved fine results with Silver Fi's excellent cabling and even the wallet-friendly DH Labs Q10, Audio Magic's Clairvoyant 4D cables were pure sex. Since Roy is a fan of Audio Magic, he asked Jerry Ramsey to send up a set of his Clairvoyant 4D speaker cables and two pairs of matching interconnects. Oh my. Talk about opening the flood gates. The speed and dynamics these cables imparted were awesome. They somehow helped the system fill my room with considerable presence and energy. And while I'd be the last person to suggest you fire up your credit card to the tune of $9,500 for cables, this match sure worked wonders. Usually when I see $4,500 speaker cables and $2,500 interconnects, I feel the urge to call a rape crisis center as my audiobud Jim is fond of saying. Frankly, I'd never spend that much on cables no matter how good they might be. But I'm not you so feel free to fill your boots. I did try the Clairvoyants with my Manley gear and the AV123 Strata Mini I also have in for review and the resultant sound was less than stellar - bright, edgy and fatiguing. The Clairvoyants are clearly not for every system and as with anything else, try before you buy. But with the Callisto or Calypso, they were - ahem, magic.

I also auditioned the Calypso with my REL Q-108 subs for a spell. The speakers certainly don't require a sub to sound full and robust down low but as with every speaker I've tried, a properly integrated sub or two consistently improved performance. I experienced no difficulty in obtaining a seamless match with the Calypsos. Don't believe the nonsense about subs having no place in an audio system. It's all a matter of finding a decent sub and experimenting with proper placement, crossover, phase and level settings. GMA offers their own subs but also recommends Dayton's keenly priced Titanic sub kits available at www.parts-express.com.


Calling the Calypso's presentation natural smacks a tad of reviewer cliché but once you hear these speakers, the term seems an ideal descriptor. It didn't matter how long I listened or to what genre of music, I did not experience the slightest inkling of fatigue or boredom. Instrumental and vocal timbre was spot on. Beats, rhythmic flow plus the sense of drama and excitement were all there. There was plenty of grip, speed and dynamically, they would turn on a dime.