review - troels gravesen · page 3 of 6 measurements all measurements were done with a 82 uf...
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![Page 1: Review - Troels Gravesen · Page 3 of 6 Measurements All measurements were done with a 82 uF capacitor in line with the tweeters. Ribbon tweeter flush-mounted on a 60 x 100 cm baffle](https://reader030.vdocuments.site/reader030/viewer/2022040200/5e407d06d21f7f66086c1230/html5/thumbnails/1.jpg)
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.
![Page 2: Review - Troels Gravesen · Page 3 of 6 Measurements All measurements were done with a 82 uF capacitor in line with the tweeters. Ribbon tweeter flush-mounted on a 60 x 100 cm baffle](https://reader030.vdocuments.site/reader030/viewer/2022040200/5e407d06d21f7f66086c1230/html5/thumbnails/2.jpg)
ReviewbyTroelsGravesen(Denmark):http://www.troelsgravesen.dk/Viawave-GRT-145-4.htm
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Frommyfirstimplementationofthisribbon,theATiRiIfoundthisribbonaverygoodalternativetotraditionaldomesofanykind.Evaluatingthesoundofaspecificdriverisfutilewithoutatthesametimetakingintoaccountthematingdriverandcrossoverimplementation.IfoundthisribbonaworthypartnertothenewAudioTechnologymid-bass.
![Page 3: Review - Troels Gravesen · Page 3 of 6 Measurements All measurements were done with a 82 uF capacitor in line with the tweeters. Ribbon tweeter flush-mounted on a 60 x 100 cm baffle](https://reader030.vdocuments.site/reader030/viewer/2022040200/5e407d06d21f7f66086c1230/html5/thumbnails/3.jpg)
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.
![Page 4: Review - Troels Gravesen · Page 3 of 6 Measurements All measurements were done with a 82 uF capacitor in line with the tweeters. Ribbon tweeter flush-mounted on a 60 x 100 cm baffle](https://reader030.vdocuments.site/reader030/viewer/2022040200/5e407d06d21f7f66086c1230/html5/thumbnails/4.jpg)
ReviewbyTroelsGravesen(Denmark):http://www.troelsgravesen.dk/Viawave-GRT-145-4.htm
Page4of6
Measurements
Allmeasurementsweredonewitha82uFcapacitorinlinewiththetweeters.Ribbontweeterflush-mountedona60x100cmbaffle.
Impedance.Basicallya4Ohmsdriver.
Distortionmeasuredat0.25mdistanceandinputequalto~95dB/1meter(4-17kHzrange).
Green=2ndharm.,blue=3rdharm.
![Page 5: Review - Troels Gravesen · Page 3 of 6 Measurements All measurements were done with a 82 uF capacitor in line with the tweeters. Ribbon tweeter flush-mounted on a 60 x 100 cm baffle](https://reader030.vdocuments.site/reader030/viewer/2022040200/5e407d06d21f7f66086c1230/html5/thumbnails/5.jpg)
ReviewbyTroelsGravesen(Denmark):http://www.troelsgravesen.dk/Viawave-GRT-145-4.htm
Page5of6
Measurements
Allmeasurementsweredonewitha82uFcapacitorinlinewiththetweeters.Ribbontweeterflush-mountedona60x100cmbaffle.
Distortionmeasuredat0.25mdistanceandinputequalto~100dB/1meter(4-17kHzrange).2.8
voltsapplied.Green=2ndharm.,blue=3rdharm.Thisdoesn'tchangethepictureatall.Impressivelowleveldownto1kHz.
Herethecumulativespectraldecay.Clean!
![Page 6: Review - Troels Gravesen · Page 3 of 6 Measurements All measurements were done with a 82 uF capacitor in line with the tweeters. Ribbon tweeter flush-mounted on a 60 x 100 cm baffle](https://reader030.vdocuments.site/reader030/viewer/2022040200/5e407d06d21f7f66086c1230/html5/thumbnails/6.jpg)
ReviewbyTroelsGravesen(Denmark):http://www.troelsgravesen.dk/Viawave-GRT-145-4.htm
Page6of6
Measurements
Allmeasurementsweredonewitha82uFcapacitorinlinewiththetweeters.Ribbontweeterflush-mountedona60x100cmbaffle.
Stepresponse.