Reviewer: Srajan Ebaen
Source: Zanden Audio Model 5000 MkIII DAC; Accustic Arts Drive I
Preamp/Integrated: Bel Canto PRe2; Eastern Electric MiniMax
Amp: AUDIOPAX Model 88; Bel Canto Design eVo4 Gen.II; Wyetech Labs Sapphire [on review]
Speakers: Avantgarde Acoustic DUO; Gallo Acoustics Reference 3
Cables: HMS Grand Finale; Crystal Cable Reference complete wire set of interconnects, speaker cables and power cords; Z-Cable Reference Cyclone power cords on both powerline conditioner; 2 x Stealth Audio Cables Indra analogue & Varidig S/PDIF cables [on review]
Stands: Grand Prix Audio Monaco four-tier
Powerline conditioning: BPT BP-3.5 Signature; Walker Audio Velocitor for source components
Sundry accessories: GPA Formula Carbon/Kevlar shelf for tube amps; 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 and significant 'active' cubic air volume of essentially the entire (small) house
Review component retail: $3,500/pr
Ask any speaker designer about the theoretical ideal of the craft. Chances are what? That you'll hear pulsating sphere ad infinitum, pure and simple. A pulsating sphere is the only transducer shape/dispersion geometry that duplicates how sound propagates in nature: Omni-directionally from a virtual point source. Bipolars attempt to mimic omni dispersion, dual- or tri-concentrics mirror the point-source principle. Arguably no raw driver comes closer to the pulsating sphere ideal than mbl's famous bending-wave device or, in more bandwidth-restricted form, Acapella's ion tweeter. Anthony Gallo's CDT is a 300-degree pulsating cylinder while the Walsh, Duevel and B&O speakers produce 360 dispersion from upfiring drivers with or without dispersion lenses. There are more citable examples by regular bipolar champions Mirage and Definitive Technology but you get the idea: The ideal seems universal, real-world implementations far and few between.

John T. Larsen of Artistic Audio in Blue Springs/MO would rightly argue that the above list remains incomplete without a mention of his Möbius loudspeaker. The Möbius goes about the pulsating sphere implementation with conventional dynamic drivers in about as literal a way as conceivable. It configures two dome midranges back-to-back, then piggybacks bridge-mounted softdome tweeters atop each for both point source behavior and omni-directional dispersion. To extend bass response, the triangular enclosure that holds up the elegantly angled and lacquered tuning fork baffle with the grill-covered sphere houses mirror-imaged side-firing woofers.

The piece-de-resistence of John's design hinged on developing 8" dome drivers whose magnet structures would allow tight back-to-back mounting for the desired 'spherical transducer'. Resulting in two patents along the way, these drivers sport massive 6" voice coils, neodymium magnets and talc-filled cones with a convex rubber surround. Conceptually borrowing from car audio technology, the 1" ferrofluid-cooled silk dome tweeters hover in front of the 8" midrange domes suspended via a compliant plastic bridge. An 8" rear-ported woofer fires sideways from the bottom of the support enclosure. With a specified frequency response of 45Hz - 20,000Hz +/- 3.2dB, sensitivity of 88.3dB, 8-ohm nominal impedance and 250 watts power handling, Möbius is a svelte customer of 42" H x 12" W x 15" D dimensions and a modest poundage of 55. Six coats of silver lacquer adorn the baffle while black leatherette clads the enclosure proper. Bi-wire terminals with removable straps are standard as are four threaded cones with T-nut counter parts for floor coupling and leveling adjustments.

Though a claimed easy load that should do fine with my 30-watt Audiopax monos as well as the very potent Wyetech Labs 18-watt Sapphire paralleled 300B monos, I would also press my 120/360wpc Bel Canto Design eVo4 into service to observe how high current and those 6-inch voice coils might cohabitate. To the left is a cutaway photo from a CES that shows how the four drivers do indeed approach the spherical ideal to an uncanny extent using 'conventional' driver technology adapted for this special employ.


My resident Gallo Acoustic Reference 3 speakers with their spherical midrange driver housings, mirror-imaged woofers, omni tweeter and retail of $2,595 ($3,500 with the optional Reference 3 SA bass amplifier) are natural competitors to the Möbius and will duel it out on the floor chez Ebaen. Stay tuned for the blow-by-blow account of this exciting match.


I'll be particularly curious about the Möbius' midrange and upper bass performance. While still working with the Soliloquy Loudspeaker Company three-some years back, Phil Jones had designed a 3-inch silk-dome driver for their Model 6.5. Alan Yun of Silverline Audio fancies a similar unit from a European supplier. There must be others - but none to my knowledge exceed a 3-4" diameter. I'm rather certain there must be specific engineering reasons likely to do with off-axis response why larger drivers these days favor cone or even flat diaphragms and limit the dome shape to tweeters and certain rare small midranges. The rather articulated curvature of Artistic Audio's driver in the above cutaway is a distinctly unusual feature conceptually well suited to the spherical ideal. But not all god-on-paper concepts in audio translate into superior subjective performance. Would the 'Modern Art' Möbius prove or defy the common rule that a lot of seemingly different-to-be-different designs often don't exceed mere curiosity value? Or to be blunt, if this was such a good idea, how come nobody has attempted it before in a segment of the industry where precious little of true novelty occurs under the sun? Of course then there are the two patents. They could prove the point in a thoroughly convincing way. I for one couldn't wait to find out how the pendulum would swing.