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Reviewer: Srajan Ebaen
Source: Zanden Audio Model 5000 MkIII DAC; Accustic Arts Drive-1; Audio Aero Prima [on review]; Einstein CDP [on review]
Preamp/Integrated: Bel Canto PRe2; Wyetech Labs Pearl [on loan]; Einstein integrated [on review]; Audiopax Model 5 [on review]
Amp: AUDIOPAX Model 88, Bel Canto eVo 4 Gen.II
Speakers: Avantgarde Duo; Gallo Acoustics Reference 3
Cables: Stealth Audio Varidig S/PDIF, Stealth Audio Indra (x2), Crystal Cable Reference speaker cable and power cords; ZCable Hurricane power cords on both conditioners
Stands: 2 x Grand Prix Audio Monaco four-tier
Powerline conditioning: BPT BP-3.5 Signature for source components; Walker Audio Velocitor
Sundry accessories: GPA Formula Carbon/Kevlar shelf for transport; GPA Apex footers underneath stand and speakers; Walker Audio SST on all connections; Walker Audio Vivid CD cleaner; Furutech RD-2 CD demagnetizer; WorldPower cryo'd Hubbell wall sockets; Musse Audio resonance dampers on DUO subs; Mapleshade 4" solid maple platform under BPT conditioner
Room size: 30' w x 18' d x 10' h [sloping ceiling] in long-wall setup in one half, with open adjoining living room for a total of ca.1000 squ.ft floor plan
Review Component Retail: $9,995/pr in all black, $11,995/pr in Cherry as shown, $13,995/pr in designer wood options [listed below]; $300/pr for biwire; $600/700/900/pr for black, Cherry or optional top grill cover to hide the sculpture; $150/pr for 200-hour high-volume factory break-in [recommended for all apartment dwellers or others who never listen loudly and thus fail to break in their speakers]

The Denver/Colorado Springs corridor of Colorado is home to some mighty famous audio firms: Jeff Rowland Design Group, Edge, Avalon, InnerSound, Boulder, Ayre Acoustics and Audio Magic. It's home also to Green Mountain Audio, a speaker design house that should be equally famous but -- outside of a certain underground of true cognoscenti -- isn't yet nor has it garnered the press coverage it deserves. Today's review of GMA's flagship model Continuum 3 will explain why designer Roy Johnson is one of speaker design's unsung heros and one you're bound to hear much more about in the next few years.

You see, once we venture beyond what despite commercial success or standing really aren't more than amateur applications refined over time through extensive trial'n'error, speaker design is dominated by electrical engineers. It is rare to find bona fide physicists or mathematicians or chemists involved. How does the saying go? If you're a hammer, all problems are reduced to nails? Considering the common challenges of speaker design exclusively from an electrical engineer's perspective is bound to nail down solutions that don't take into account insights that would require data generated from other scientific disciplines. Limited perspective equals limited solutions. Here's an example. Eduardo de Lima of Brazil's Audiopax had spent 6 years of mathematical modeling to lay the foundation for his revolutionary TimbreLock. It
accounts for THD interactions between components and is a truly novel approach to component design. His new preamp has recently demonstrated how to adapt TimbreLock to solid-state. It proves that the principles behind it aren't limited to valved peculiarities. A bevy of reviews confirms that TimbreLock is no gimmick. It works exactly as claimed. However, without advanced applied math, Timbre Lock wouldn't exist. To conceive of it in the first place and then work out the science behind it required a mathematician's understanding, period. Ditto for Green Mountain Audio. Without cracking the secret code of advanced time-domain math, this company wouldn't exist either.

From a purely electrical perspective, the time domain -- e.g. the mandate that all frequency components of a signal played back over a loudspeaker must reach the listener's ear coincidentally and at exactly the same time as they do in nature -- is treated as utterly negligible (even though were the same nonchalance applied to any other audio component, listeners and reviewers alike would call them broken and unfit for use). If wholesale disregard of this maxim weren't so widespread, we'd have far more Vandersteens, Thiels, Meadowlarks and Ascendos struggling hard to design to its requirements. It's become nearly a truism that despite solid reasons to the contrary, time coherence in loudspeakers is inaudible. But if that were a lie and time fidelity was audible, why does such mythinformation prosper and survive so successfully? Simple. To prove the audibility of time alignment requires that rare loudspeaker as we have in the adjustable GMA or Ascendo [right] whose time-domain parameters can be altered without affecting anything else (such as a change in cabinet reflections).

You can't just waltz into a store and compare a B&W to a Vandersteen to determine anything of substance concerning time-domain fidelity. But you can deliberately screw up the adjustable time-domain performance of Green Mountain Audio's Continuum 3 to really compare apples to apples. If the coincident arrival of all frequencies launched by different drivers didn't matter as most all speaker designers go on claiming, you shouldn't hear a difference. Adjust the cast-composite minimum-diffraction two-way head unit of the three-way Continuum. Listen. There's a difference. If this difference didn't matter, you shouldn't be able to tell by ear when you've gotten the adjustment right. Guess what? It takes no golden ear to either hear the difference or hear when it's right. Time domain fidelity isn't audible? That's a bunch of smelly poppycock.

It turns out that many audio aberrations blamed on components and cables are functions of speaker timing errors such as a foreshortening of the depth perspective or transient hardness and emphasized sibilants. The latter is easy to understand. If the higher harmonics of a transient are generated by a tweeter but arrive at your ear before the fundamental because the midrange's arrival is delayed in time, things sound hard and strident. Once that tweeter is aligned properly, you retain speed and attack but the former zippiness is now counterbalanced by the midrange fundamental and tweeter harmonics arriving on time to sound natural rather than edgy. Proper timbre is another obvious beneficiary when the harmonic envelope that gives instruments and performers their sonic signature arrives in one piece rather than being discombobulated and scattered by phase rotations.

Natural sizing and performer focus is another aspect of playback performance that benefits not only from proper time-domain behavior but rigorously -- in GMA's case you might even say heroically -- applied addresses against cabinet talk (fuzziness) and wave launch distortions (cabinet reflections). Roy's Q-Stone is a chemist's dream of ultra-fine marble dust suspended in proprietary polymers that weighs in at 90 lbs per cubic foot. His complicated lock joinery is a woodshop's nightmare but results in joints of superior strength to take the cabinet out of the audible equation.

The mathematically modeled head sculpture moves fore and aft on Nylon bushings and is locked in place with long screws drilling directly into the cast marble composite. The upper swivel joint rotates around an axis that bisects the 5.25" Aerogel midrange's acoustic center to fix the vertical angle from which midrange and tweeter fire at the listener.

The 1" soft-dome Morel tweeter is, according to the designer, the only one on the market designed around free-air measurement applications rather than customary baffle reinforcement. The resistive loading of the midrange is probably an industry-first never before adapted from previous woofer porting solutions. The F-Hole bracing of the woofer cabinet replaces former GMA transmission lines and is vented out the top right behind the head module. A single-wire terminal minimizes associated cabling cost (the wire tail to the head unit is a combination of Audio Magic and Jena Labs cabling).

For an appreciation of the protracted build process involved in a pair of Continuum 3s, consider that the precision-cast composite parts undergo shrinking when curing, something that Roy had to account for just so when designing the rubber molds. There's apparently 200 different operations involved to build one pair of 3s, just one of which is application of the tough black Texture-Kote paint. Wooden parts are cut to +/- 1/100th of an inch tolerance. Wood stains are mixed in-house. Drivers and crossover components are pair-matched to within +/- 0.25dB. Phase shift is less than one degree from 300Hz to 8kHz. Custom wood cheeks in Bolivian Rosewood, African Ribbon Mahogany, Cocobolo, Bocote, Tulip wood, Burled Oak, Zebra wood, Quilted Maple, Bubinga, Myrtle, Curly Koa, Turkish Walnut, Macassar Ebony and Lace wood are available by special order. An "ear poker" device of modular wooden pieces is included to be mounted atop a camera tripod and determine the exact location of your ear in your customary listening chair. After measuring the path length between that point and the woofer dust cap, simply add 1.11/16" to the midrange and another 11/16" to the tweeter and you've locked in proper time arrivals such that the tweeter and woofer seem to originate from the physical position of the midrange when you close your eyes. In other words, the drivers lock in "as one" to produce what Roy Johnson calls Soundfield Convergence.

He needs my fully factory-broken-in review loaners for CES when he introduces the new Pico and Calypso models, the latter a smaller brother of the Continuum 3. Thus expect my full review around the 15th of next month. Our resident 1st-order maniac Paul Candy meanwhile is scheduled for receipt of the 2-way Callisto model in mid December to report from the Cold White North and help do our part in securing Green Mountain Audio some of the respect it deserves by way of press coverage. Readers of the Asylum who have communicated with Roy over the years already know that when it comes to the Physics of 1st-order loudspeaker design, there's probably nobody on the planet more knowledgeable than Mr. Johnson. Like Eduardo de Lima, he's a very intelligent, highly educated yet humble and casual fellow. And like de Lima, his single-minded obsession with tough-as-nails mathematical research to advance the state-of-the-art in his field has undermined his ability to develop a long-term business plan and not just design what insiders believe are some of the best dynamic speakers on the market but actually do so in such a way as to have a large number of people know that he does.

The arrival of new CEO Janet Lynn in July of this year and one look at her very impressive credentials and list of prior accomplishments predicts massive changes in this regard. For now, Green Mountain Audio is still the equivalent of an insider's tip far too few people know about. Consider today's introduction to the GMA Continuum 3 a completely legit spill of the beans. And to slay one of the dragons bedeviling public perceptions about 1st-order designs, these speaker can play ungodly loud. Roy demonstrated a live Tangerine Dream cut wherein, to thunderous audience applause, one guy whacks away at massive drums to such an extent as to make Japanese Kodo drummers envious. I'm talking bloody uncomfortably loud. I'm talking no compression, no nastiness, no falling apart, just properly scaled output levels. There are other misconceptions about this breed of speaker that I will address in the review proper. For now, consider the promise of a minimum-phase minimum-parts crossover married to the right (modified and very expensive) drivers in a cabinet whose sculpted contours avoid reflections and whose non-ringy construction turns a stone face at resonances [C3 molds below].

Since the generic loudspeaker is by far the largest contributor of distortions in the audio chain (well past a factor of 10 compared to amplifiers and source components and cables), what do you think would it sound like when you drastically reduced this distortion? As far as crossovers are concerned, Roy suggests a simple experiment. Take a preamp signal, put it through higher-order electronic pro-audio crossovers, then Y their outputs back together and listen to the results via headphones (which, being crossover-less, won't introduce their own time-domain distortions). Be prepared for a crash course in what crossovers do to the sound. Now factor into the equation the difference between a talkative and a mute cabinet. Now minimize cabinet reflections common to rectangular box speakers. Do you get the idea that the result would have to be a precision instrument that gets out of signal's way to a most uncommon extent?
Optional C3 grill cover in Cherry