ReviewbyTroelsGravesen(Denmark):http://www.troelsgravesen.dk/Viawave-GRT-145-4.htm
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ExcerptfromViawavewebsite:“ViawaveAudioproudlyintroducesatrueworldfirstintheGRT-145;thetechnologyofsealingtheairgapbetweentheribbonandthepolesofthemagnets.DevelopedbyViawaveAudio,thistechnologyiscalledSRT-thesealedribbontweeter.IntheSRT,thegapbetweentheribbonandthemagnetsiscoveredwithaU-shapedmylarsuspension.Thisdramaticallyreducesharmonicdistortionsatlowfrequenciesoftheoperatingrangewhilstalsoincreasingthesensitivityby2-3dB.BycombiningourSRTtechnologyandapowerfulmagneticsystem,auniquesensitivitywasachievedforaribbonof7cm2-95dB/W/min4-18kHzrange.Inatweeterwitha4-Ohmresistoritcorrespondsto98dB/mat2,83V.”IhadamailfromthecreatorofthisribbontweeterandbasedontheinformationavailableIrequestedapairforevaluation.Heremymeasurementsandcomments:Intermsofoverallappearance,theseribbonsappeartobeverywellbuiltwithexcellentfinish.Myprimaryconcernwithribbontweetersisdispersion,butthistweeterhasanexcellenthorizontaldispersionwithverylittlelossevenat30deg.off-axis.Verticaldispersionissurprisinglygood,oneofribbons'usualdrawbacks,andgooddispersionat20deg.off-axisisexcellent.Overallfrequencyresponseisflat,formymeasurementsabitflatterthansuggestedbyViawave.Measurementssuggest95-97dBsensitivityinthe1-3kHzrangerisingsome100-102dBsensitivityfrom4kHzto18kHz.QuiteimpressivealthoughIwouldpreferahigherimpedanceandlowersensitivityasmostspeakerconstructionsrarelyrequiremorethan88-92dBsensitivity.Thiswouldalsosavequitesomemoneyingoodcapacitorsforthecrossover.Distortionisverylow,[email protected](100dB)andsuggestevenanLR2filterat2kHzmaybepossible,notacommonfeatureofmostsmallerribbons.Impedanceisfairlyflatandmakescrossoverworkeasy.Ihavesimulatedtheribbonwithfourofmyconstructionsandthissuggestseasyimplementation.Duetodepthoftheribbon,onlymodeststeppedbafflemaybenecessary.
ReviewbyTroelsGravesen(Denmark):http://www.troelsgravesen.dk/Viawave-GRT-145-4.htm
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Frommyfirstimplementationofthisribbon,theATiRiIfoundthisribbonaverygoodalternativetotraditionaldomesofanykind.Evaluatingthesoundofaspecificdriverisfutilewithoutatthesametimetakingintoaccountthematingdriverandcrossoverimplementation.IfoundthisribbonaworthypartnertothenewAudioTechnologymid-bass.
ReviewbyTroelsGravesen(Denmark):http://www.troelsgravesen.dk/Viawave-GRT-145-4.htm
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Measurements
Allmeasurementsweredonewitha82uFcapacitorinlinewiththetweeters.Ribbontweeterflush-mountedona60x100cmbaffle.
Horizontaldispersionat0,10,20,30and40deg.off-axis.Measurementsequivalentto2.8V/1
meter.Overallsensitivityis95-102dBfrom1-20kHz.
Verticaldispersionat0,10,20,30and40deg.off-axis.
ReviewbyTroelsGravesen(Denmark):http://www.troelsgravesen.dk/Viawave-GRT-145-4.htm
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Measurements
Allmeasurementsweredonewitha82uFcapacitorinlinewiththetweeters.Ribbontweeterflush-mountedona60x100cmbaffle.
Impedance.Basicallya4Ohmsdriver.
Distortionmeasuredat0.25mdistanceandinputequalto~95dB/1meter(4-17kHzrange).
Green=2ndharm.,blue=3rdharm.
ReviewbyTroelsGravesen(Denmark):http://www.troelsgravesen.dk/Viawave-GRT-145-4.htm
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Measurements
Allmeasurementsweredonewitha82uFcapacitorinlinewiththetweeters.Ribbontweeterflush-mountedona60x100cmbaffle.
Distortionmeasuredat0.25mdistanceandinputequalto~100dB/1meter(4-17kHzrange).2.8
voltsapplied.Green=2ndharm.,blue=3rdharm.Thisdoesn'tchangethepictureatall.Impressivelowleveldownto1kHz.
Herethecumulativespectraldecay.Clean!
ReviewbyTroelsGravesen(Denmark):http://www.troelsgravesen.dk/Viawave-GRT-145-4.htm
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Measurements
Allmeasurementsweredonewitha82uFcapacitorinlinewiththetweeters.Ribbontweeterflush-mountedona60x100cmbaffle.
Stepresponse.
