Truthful to the Music - Piega SA

FocusPRODUCTSPEAKERSNestled against Lake Zurich, in thetown of Horgen, Switzerland,Piega’s headquarters gives theimpression of a company in harmony withits environment. As you will see, Piega is,indeed, about as “Green” as a speakermanufacturer can be: No trees are killedin order to fabricate its cabinets. Foundedin 1986 by Leo Greiner and Kurt Scheuch,Piega has grown steadily to become thepremier Swiss speaker manufacturer.Its goal from the beginning was to staytruthful to the music, to consider thespeaker as a conduit of recorded soundfrom the concert hall or recording studioto the listening room. This ideal has beenpursued for over 20 years with technicalinnovation and precision craftsmanshipin the tradition of Swiss watchmakers.Transient speed was deemed to bean essential design goal—and why not?Music, after all, is all about transients,whose characteristic attack and decayhelp define an instrument’s timbre. Theevolution of an instrument’s harmonicenvelope is key to preserving its timbralrealism. (This effect can be easilydemonstrated by playing an audiotapeof a piano backwards, which causes thepiano to be perceived as a pipe organ.)In pursuit of electrostatic sound qualityin a smaller package, Piega developed anew ribbon tweeter in 1986, and has sincestayed faithful to ribbon technology. In2000 Piega reached another milestonewith the introduction of the world’s firstcoaxial-ribbon mid/tweeter driver. Theterm coaxial refers to a dual-elementdriver design in which the acousticalcenters of each driver element are spatiallyaligned, in contrast to a typical multiwaysystem where the tweeter and midrangeare spaced apart on the front baffle. Atthe crossover frequency in the uppermidrange, a wavelength is on the orderof six inches—or roughly the spacingbetween the drivers’ acoustic centers.Why is that a big deal, you ask? Becausethe summed output of the drivers inthe crossover region is subject to waveinterference. There is usually an axis onwhich the combined frequency responsePiega TC 10 X LoudspeakerTruthful tothe MusicDick Olsherof the drivers is pretty uniform. But movethe measurement microphone a coupleof inches off axis, and you discoverconsiderable output cancellation. Mappedout in 3-D, speaker output in this regionwould be seen to exhibit lobes—hot andcold spots of sound-pressure level. Ofcourse, manufacturers are adept at puttingtheir best feet forward, and officiallypublishedresponse curves usually presenta best-case scenario. However, at thelistening seat, such a speaker is unlikelyto image well, as small head movementsmodify perceived response.During the 1970s Sigfried Linkwitzwas the first to analyze and developa crossover network topology thatexplicitly accounted for non-coincidentacoustic centers. Prior to that, traditionalcrossover networks assumed that alldrivers shared a common acoustic origin.And while the Linkwitz-Riley networkrepresents a step in the right direction,in the final analysis, there is no substitutefor a successful coaxial design. The Piegacoaxial ribbon driver is a case in point. Theflat midrange foil membrane surrounds acentrally located tweeter ribbon, lockingboth drivers’ acoustic centers in the samespatial location and resulting in uniformphase response across the crossoverregion. The midrange foil, only 0.02millimeters thick, is driven over its entirearea by neodymium magnets in pushpullfashion—the ideal “force over area”drive principle. Strictly speaking, themidrange is a magnetostatic planar driver,analogous to an electrostatic, except thatmagnetic rather than electrostatic force isused to move the diaphragm. The tweeterribbon element is embossed and mountedstrain-free on all four sides to ensuredamping of longitudinal bending waves.The ribbon kicks in around 3.5kHz, andthe entire assembly covers the frequencyrange from about 400Hz to 50kHz.A small version of this coaxial driver(model C2) is used in the TC 10 X, and inall other Piega models denoted with theletter “X.” No doubt about it, the coaxialribbon driver is a high-tech product, saidto take up to four hours of painstakingcraftsmanship to build under controlledenvironmental conditions.When it comes to cabinetry, Piegaalso follows the road less traveled.Whereas most manufacturers start withan “industry standard” MDF cabinet andthen work hard to control flexure, Piegacuts right through the Gordian Knotof the traditional cabinet resonances78 November 2007 The Absolute Sound

juice up apparent detail, and very fewaudiophiles complain about too muchbass. The Piega, on the other hand,bucked this trend and offered almost nopersonality of its own. First impressionwas of a seamless presentation. Inparticular, the midrange-presenceregionboundary, a troublesome spotfor conventional tweeters crossed overaround 3kHz, blended beautifully. Themusic’s character remained unchangedover the bandwidth of the coaxialdriver, with never a hint of brightnessor dissonance despite its extended treblerange. Soprano upper registers and violinovertones soared naturally and delicately,unencumbered by distortion products orresonances. As you can imagine, heavilyprocessed multitrack recordings greatlybenefited from the Piega’s squeaky-cleancharacter. The ability to negotiate poorrecordings gracefully is a major bonus forall of us whose record collections spanmuch more than a sanitized subset ofaudiophile recordings.The core of the midrange was renderedwith crystalline clarity, allowing tonecolors, textures, and low-level detail tobe resolved with disarming naturalness.Complex passages were readily clarifiedand with a masterful sense of speedand transient control that—well, I haveto agree with the advertising copy—iselectrostatic in character. Dynamicswere closely tied to the choice ofamplification.The Piegadisappeared betterthan any conventionaltwo-wayAround 100Wpc seemed to producethe most convincing reproduction of anorchestral crescendo. James Bongiorno’saffordable Son of Ampzilla 200 did aparticularly noteworthy job partneringthe Piega, the combination being smooth,sweet, and dynamic. This is not to saythat more expensive amplifiers were alost cause with the Piega. Au contraire,the ultra-high-end Silicon Arts DesignZL-120 was clearly higher in resolutionthrough the lower midrange.I’ve left the best for last. Forget Britishmini-monitors—this is the new champwhen it comes to pinpoint imagingprecision and stability. I’m sure that itssuperb driver integration and coherencethrough the critical mids and upperoctaves play a major role in its imagingprowess. Wide, spacious, and slightly laidback,the soundstage was populated withimages etched with laser-like precision.Massed voices were readily resolvedand the impression of an organic space,completely independent of the speakers,was remarkably strong. And, yes, the Piegaperformed the proverbial disappearingact better than any conventional two-waymini-monitor I’ve auditioned to date, andlet’s not forget that this is a three-wayspeaker. Bravo!Detailed, yet relaxed, the Piega is ableto caress musical lines with speed, finesse,and no artificial aftertaste. A hard dayin the office? Park yourself in front ofthe Piega, kick off your shoes, and pouryourself a glass of wine. The Piega TC10 X loudspeaker represents the perfecttransportation to a higher dimension ofmusical enjoyment. TASThe Absolute Sound November 2007 81