Electro-Voice EVI-12 User guide

EVI-12, EVI-15 and EVI-28
LoudspeakerSystems
Applications Guide

WelcometotheworldofVariIntense®horn
technologyfromElectro-Voice. ThisApplications
Guideisnotintendedas a “very intense”descrip-
tionofinstallationprocedures,butmoreasapartial
descriptionofapplications and a discussion with
thedesignertohelpyouunderstandthisrevolution-
arytechnologyandusethe Electro-VoiceVariIn-
tense®systemstoinstall better-soundingsystems
andsignificantlyreducetimeandmaterialcosts.
Inanutshell,herearethemajoradvantagesof
thenew EVIsystems:
• Rectangular coverage pattern.
Traditional horns deliver an elliptical pattern
to the floor. VI horns deliver a rectangular
pattern, which helps to fill in the corners of
the room. No more costly delay lines or cheap
seats!!
• Even SPL front-to-back.
The unique, patented throat and flare struc-
ture of the VI horn delivers a 6-10 dB hotter
signal to the rear of the room, eliminating ear-
strain at the back of the seating area and pain-
ful ears at the front.
• Greater Intelligibility.
VI horns deliver sound to fill only the
floorplan, providing uniform direct-field SPL
and an order of magnitude less energy into
the reverberant field. This provides an increase
in mid- to high-frequency intelligibility of 6 dB
in most applications.
• One horn replaces two.
With VI technology we’ve eliminated the de-
structive interference which occurs between
long- and short-throw horns. We’ve also elimi-
nated the cost of a properly designed two-horn
system which must include another power am-
plifier channel for good power control and
impedance matching.
• Labor savings in the box.
With structural rigging from the factory, these
systems will fly more conveniently and in less
time than many competitive products. In addi-
tion, less time is spent on the aiming and repo-
sitioning that is required with traditional long-
throw/short-throw horn combinations. This
will save you additional money.
1

2
Installationproceduresfor anyconventional
loudspeakerarefairlywell-defined andeasytoun-
derstand:findanappropriatehangingheightand
positionthataffordsaclearpathtothelisteningarea
(such as above the center of a stage or above the
lectern in a church), and aim the loudspeaker to-
wardsthecenterorjustto the rear of center ofthe
room. With this method you hope to cover the
majorityofthe room withfairlyconsistentsound,
butthe midandhighfrequenciesnever seemtofill
perfectly. It isfrequentlyaimedalittletoofarback
and there is a large amount of slap echo, or the
frontrowis tooloud,the backrowtoosoftandthe
frontand back row corners sound muted due to a
lackofhigh-frequency energy. Othersolutionsto
filling the room have been suggested and imple-
mented, including a dual-horn format (one long
throw and one short throw). This method works
fairly well, but encounters several problems: the
addedexpenseofanotherhorn/drivercombination;
thevastlyincreasedtimetophysically install and
thentunethelevel andaimingoftwohorns;thein-
evitabledestructiveinterferencepatternsthrough-
outthelisteningarea;theexpenseofanotherampli-
fierchanneltoachieve correct impedancematch-
ing;andtheneed for averyaestheticallyclean in-
stallation,withno odd-looking (to the customer)
danglinghorns. Anothersolutionisto haveahorn
that is variable angle, in order to throw a narrow
patterntothebackoftheroom. Theproblemwith
this concept is that this doesn’t take into account
thedropin SPL betweenthenearthrow (about 25
feet) and thefar throw (about 70 feet), sothehigh
frequenciesareabout10dBdowninthebackofthe
room. To solvealloftheseproblems,the VariIn-
tense®hornswere invented,yetanother innovation
inthelongtraditionofElectro-Voice. Whenproperly
aimed,theVariIntense®hornscanprovideextremely
evenSPLthroughout anentireroom,filling inthe
corners without pushing too much energy at the
back wall, thus avoiding slap echo. The rules of
fixedinstallationhavejustchanged...
The Electro-Voice EVI-12, EVI-15 and
EVI-28enclosures arethefirstinanewgeneration
ofproblem-solving systems. Thenewsystemsare
designedasa package,witheasymounting, refin-
ishingability,lightweight,compactandunobtrusive
sizeandshape and the classic musical sound that
Electro-Voiceisknownfor. Thenewsmall-format
VI horn maintains consistent directional control
downto2,000Hz. IntheEVI-12 and EVI-15 the
VI horn is optimally crossed over to an specially
angledwoofer. Note: the12-in.driverin theEVI-
12isatadifferentanglethanthe15-in.driverinthe
EVI-15,optimizingthefloorpatternwiththediffer-
ingdirectivitiesof thetwodrivers. Inthe EVI-28,
theVIhorniscrossedovertoapairofvertically-
arrayed8-inchwooferswithaproprietarytechnique
thatprovidesdelay,amplitudeandfrequencyshad-
ingtothetwo woofers.
TheEVI-12,EVI-15andEVI-28systemsare
installed just like any conventional loudspeaker,
keepinginmindafewsimpleguidelines. Letme
prefacetheseguidelineswitha simple but impor-
tantcomment:theVI systemsareextremelyversa-
tileand willworkinalarge varietyofapplications.
Theywillworkwellwithtallceilings,shortceilings,
rectangularrooms,slightlytrapezoidalroomsanda
wholehostofoddshapessolongasthecoverage
area is fairly close to rectangular. The larger
EVI-12andEVI-15havebeentestedinroomswith
12-footceilingsandperformedverywell,although
with reduced width of throw. A single EVI-12
wasinstalledinaroom 75-footby150-footandan
averageRT60of4.5inthemidbandandperformed
verywellwithgoodintelligibilityandaminimumof
slapecho. Ithasbeenthoughtinthepastthat ifthe
floorpatterndoesnotfittheVIhornexactly,thenit
cannotbeusedat all. This is notthecase,andif it
werethecase,wecould notusestandard constant-
directivityhornsinmostapplicationseither. The
largerVIsystemshavean “optimum”roomthat is
approximatelytwicethe heightinwidthand three
timestheheight in length. Thisistheideal condi-
tion, but the figures and descriptions that follow
shouldgiveyouagoodfeelforthewide-range ca-
pabilitiesofthesystems.
EVI-12andEVI-15Installation:
The nominal floorplan that the system will
coverwithequalSPLisapproximatelytwo“units”
widebythree“units”long,wheretheheightof the
loudspeakerdefinesthesize of the“unit.” Forex-
ample,iftheloudspeakeris18feetabovethefloor, it
willtypicallycoverafloorplanofabout36feetwide
by54feetlong. Inthistypicalinstallation(seeFig-
ure1),thebackpaneloftheloudspeakerismounted
approximately0.6units (about 11feet)backfrom
thefirstrowandhasa nominal angle of the topof
theenclosureparalleltothefloor or slightly tilted
back (2 to 3 degrees). For rooms that are much
longerthannormal,theVIsystemsareveryeasyto
aimand position to fill the entire length. Experi-
mentsinactuallisteningroomshaveshownthatwith

thesamemountingheightof18feet,butwiththe
front of the enclosure tilted up by approximately
10°(seeFigure2), thetotalfloorplannow encom-
passedthesame36footwidth, but at least 64 feet
inlength,anadditional10+feetofextension. Of
course, the front row position has moved back
about5 feetwiththechangein angleasshown,but
thisiseasytoaccountforwheninitiallypositioning
thesystem(andisexactlywhathappensifyoutake
aconventionalsystem andchangetheangle). For
rooms that are closer to square, tilting the loud-
speakersystemdownby15°providesaveryclean
square pattern. In this case, the offset to the first
row is about 0.25 times the height of the system.
For example, a tall, square room is about 60 feet
wide,andonly65 feet long. Tilting the enclosure
downby15°at a30foot mountingheightmakes a
60footwide by60foot longpattern. Theoffsetto
thefirstrowis0.25multipliedbythe30footheight,
orabout7.5feetforwardfromtheback of the en-
closure. Minoradjustmentsinaimingwillmakethe
SPLfilltheroomveryevenlywithnolossintonality
inthecornersandhighoverallintelligibility.
By contrast,atypicaltwo-waysystemwitha
60°x40° CDhorninthesamemountinglocationas
Figures1and2(seeFigure 3)produceda floorplan
that sounded tonally fairly consistentwitha20-to
24-footwidthand30-foot depth with an offset of
ninefeettothefrontrow. Onpaper,thisseemslike
adequateperformance, butintheroomit hasvery
noticeable (6dBorgreater)variationinoveralllevel
fromsidetocenter,andin someaimingcases over
10 dB of variation from front to back as well as a
pronounced lemon shape. The sides of the first
threetofiverowsin achurchandthelast fewrows
werenoticeablymuted andmuchlowerin overall
level. Asmentionedbefore,atwo-hornsystemcan
workfairlywell,but the physical offsetsrequired
forinstallation inevitablyresultinsomeamountof
destructive interference throughout the room
(see Figure 4). Figure 4 was produced using a
90° x 40° CD horn aimed down by 65° and a
60° x 40° horn aimed down by 30°. The actual
physical offsets were used to simulate the floor
responseindirect-field SPL.Thedisplayed figure
agreesverywellwiththemeasuredresponse,show-
inga14-dBvariationat4kHzinadistanceof3feet
horizontally. Tonal changesasaresult ofinterfer-
encepatternchangeversusfrequency wereclearly
audibleinan acousticallywell-behavedroom,but
wereoverallmuchlessaudiblethanforasinglesys-
temwithaconventionalCDhorn. Locatingdrivers
andhorns closer together than possible with me-
dium-formathornswillproduce somewhat better
results,butwillalwaysresultinfairlyseverelobing.
Polar measurements in 2° increments show the
lobingverywell,butthesmoothingrequiredfortrans-
lationtotheEASE10° resolutiondatabasewillelimi-
natethevastmajorityof peaks and dips,resulting
inwhatappearstobeafairlysmoothsimulation.In
contrast,thenewVIsystemshavenoproblemswith
interference,and maintainverygoodtonalityeven
fartothe sidesandtothe back,outsidethe“equal-
SPL”patternarea. Thiseffectisduetotheprecise
matchingofdirectivitiesinthemidrangeandtreble,
givingaconsistent(althoughnoticeablyquieter)fre-
quencyresponseout tonearly50 feetinwidthand
65–70feetinlength from thesame18-footheight
and0°aimingangle. Thishastheadvantageofpro-
vidingamuchmore uniform powerresponseinto
thereverberantfield, ensuring that the inevitable
reflections(minimizedbytheVIconcept)arecon-
sistentintonalquality.
EVI-28Installation:
TheEVI-28makesuseofthesame high-fre-
quency horn as the EVI-12 and EVI-15, but in-
cludesapairofhigh-power,high-efficiency8”woof-
ersina verycompactpackage. Thesystem ispro-
videdwitha2,000-Hzpassive crossoverfeaturing
tweeterprotection andaproprietarypassiveequal-
izationcircuitthatprovidesfrequency-shading,am-
plitude-shadingand timedelaytothetwowoofers.
AnAcousticLensFilteronthegrillehelpstoelimi-
natespuriouslobesandprovidesadegreeofacous-
ticloading. Thesefeaturesheavilymodifythepolar
responseofthetwowoofers,providinganextremely
uniformpolarpatternwithashapethatmatchesthe
VIhorn’suniqueSPLprofile. They also smooth
thetransitionbetweenwoofersandthehorntomini-
mizehorizontallobes,providingamazinglyeven
coveragethroughthecrossoverpoint. Thisextends
theVIcharacteristicdownto500Hzinanextremely
compactenclosure.
Thehigh-frequencyhornin the EVI-28is
mounted tilted 15° back relative to the EVI-12
andEVI-15. Alongwiththepolarsteeringinthe
woofer’scrossover,thisarrangesthedispersionfor
longthrowsrelativetothemountingheight. The
recommendedoperationalvertical angle isminus
5°from the top surface of the enclosure to minus
45°,definingamaximumusedverticaldispersion
of40°. Thestandard aimingofthesystemwhenit
3

4
ismountedaboveaflat floor is withthetopofthe
enclosureparalleltothefloor. Inthisorientation,
thesystemwill provideevenSPL overafloorplan
thatisapproximatelytwiceaswideasthemounting
height,andfivetimesaslong. Tiltingtheenclosure
downby approximately 10- to 15° relative to the
slopeofthefloor willproduceafloorplanthesame
asanEVI-12orEVI-15. Atthestandardaiming,
the45°nearfieldoperationalangledefines an ap-
proximateoffsettothefirstuseablerowofone-half
theheightofthespeakersystemabovethelistening
plane.
Ina typicalinstallation,thetopsurface oftheloud-
speakerwillpointslightly abovetheheadheightof
thefurthesttargetedseatingorstandingarea. This
willensuretheminimumamountofslapechofrom
thebackwall. Inanunder-balconysituation,the
sharp cutoff above the zero degree axis prevents
earlyceilingreflections fromcausinginterference
patternsinthelisteningarea. SinceanEVI-28has
averysmooth andrapiddrop-offtowards directly
belowthecabinet,youcanactuallystandrightin
front of the speaker (see Figure 12) without ear
strainorheavymicrophonefeedback. Theremark-
ableabsenceoflobestotherearallowsthe system
to be mounted directly overhead to target a par-
ticularareawithoutdisturbingtheaudiencebelow
orbehindthe cabinet.
Forexample,FIGURE11 shows a typical under-
balconyapplicationthathasafloorwithanupward
slopeof5°. The speakerismounted 10feetabove
the seated head height, so the horizontal width is
fixed at approximately 20 feet. The enclosure is
tiltedback by 5° to provide a 50-foot throw, with
theoutskirts of the pattern filling in the rear aisle
areawithtonallyaccuratebutreducedoverallSPL.
If the under-balcony seating area is only 35 feet
deep,thentheenclosureshould be tilted downby
about 10° relative to the floor in order to prevent
excessslapechoandpreserveintelligibility.
Figure12showsatypical small-roomapplication,
perfect for a 20-foot by 30-foot boardroom or
meetinghall. Inthiscase,theheadheightisactually
definedbyastandingheightofapproximately6feet,
sothelong-throwaxisshouldbeveryclosetohori-
zontal. Thentheincluded40degreeanglepoints
directlytowardstheentirelisteningarea,minimizing
slapechowhileretainingafullwidth,highintelligi-
bilityandevenSPL throughoutthelisteningarea.
Qvs.Intelligibility:
The“Q”ofasystemisagoodmeasureofthe
system’sdirectivity,andinsomewaysagoodmea-
sureofwhetherthesystem’sin-roomresponsewill
beconsistentacrossthefrequencyrange. Atypi-
cal12-inchtwo-waysystemwith a 60ox40ohorn
will maintain a fairly constant Q from 16-30 or
12-15 dB (normally about 26, or 14dB) from
3,000–20,000 Hz, and a 90o x 40oa Q of 13-15
(11-12dB). Very-high-directivity horns such as a
40o x 20owill have an average Q in the range of
45(16.5 dB),andvery-low-directivityhornslike a
120o x 40owill have a Q of 7-9 (8.5-9.5 dB). It is
generallythoughtthat a high-directivityhornwill
havegreaterintelligibilityacrossagivenpatternarea
thanalower-Qdevice,andthisistrueinmostcases.
Alsotruein mostcasesisthat a standardhornpat-
ternwill notfillatypicalfloorplan,thusdrastically
reducingtheeffectivenessofthehigherQ. Indirect
comparison,the VIhornpatternwillfillamajority
offloorplanswithdirect-fieldsoundratherthanre-
lyingonreverberant energy to“fillinthe gaps” in
overallsoundqualityandquantity. TheQoftheVI
systemsareveryconsistentfrom1,000–20,000Hz,
with a range of 10-18 (10-12.5 dB) and an aver-
ageQof13.5(11.5dB)orconsistentwiththeoverall
directivityofa90ox40osystem. Thismightlead
youtobelievethattheVIsystemsare“low-Q”and
inappropriateforhighlyreverberantrooms,butthe
plotsofthedirect-fieldSPL anditsaccompanying
C50 ratio show a significant advantage to the VI
systemoveraconventional60ox40osystem. Aswe
allknow,highQonlyhelpswhenthepolarresponse
fitsintothelisteningspaceascloselyas possible.
PleasekeepthisinmindwhenusingQas abench-
markforsystemintelligibility. Forthoseunfamiliar
withthetermC50, it isameasureof intelligibility
defined by the acoustic power in the room in the
first50msec divided by the power from 50 msec
toinfinity,expressedin dB.Theminimum recom-
mendedlevelofintelligibilityis0dB,roughlyequiva-
lentto10%Alcons.
ANoteonSimulationSoftware:
DatafilesforAcoustaCADDTM andEASETM
areavailablefromElectro-Voice’sBBS,byspecial
request or on Electro-Voice’s Website (http://
www.electrovoice.com). Thefigureshaveallbeen
producedinEASE,butwiththecurrent10° resolu-
tionofthesoftware,muchofthe2° resolution data
wecollecthasbeenlostin the required averaging
translationtothe10-degree format.Thenetresult

Pleasenote: thepull-uplocationonthe lower
sectionofthebackpanelof the enclosure MUST
be used to hang the system in order to provide a
safe,stablemountingsystem. Thepull-uppointpro-
videsanadditive safety,asit iscapableofholding
thespeaker system with a safety factor of at least
5:1intheunlikelyeventofafailureinthemainload-
bearingsystem.
FortheEVI-28,themountingholesareposi-
tionedverynearthecenter ofgravityfor easyaim-
ing. The U-brackets may be rotated all the way
aroundthebackof theenclosure,allowingeasyin-
stallationandaiming. Themaximumverticalangle
thatmay be reached is approximately 35°, less if
theloudspeaker ismountedflushagainsta ceiling.
Inthiscase,theenclosuremayberotatedupwards
byatleast 15°,morethansufficient fornearlyany
application(seeFigure 15). Thebracketsare sup-
pliedwithfrictionwashersthatwillpreventtheen-
closure from rotating over time, but to be abso-
lutelycertain,theinstaller shoulduseasetscrewin
thethreadedhole tofixthe enclosurepermanently
inposition.
Thedescribedhanging methodsarerated for
suspendingonlyonespeaker (with aminimumof
an 8:1 safety factor). Hanging any additional
weightfromthespeakerwillexceeditsstrength
ratingandcreateanunsafecondition.
ASamplingofEVIApplications:
Now that the technical details are covered,
here are a few ideas on applications that the EVI
systemswillcoverwithfarmoreuniformsoundand
loweroverallcostthananyconventionalenclosure.
Thefirstandmostobviousapplicationisinachurch
orsomeotherwell-definedspacethat has a fairly
tallceiling,and proportions of roughly 2 x 3 (see
Figure1). In thisapplication,theEVIsystems can
easilyreplaceacentralclusterordistributedsys-
temwithasinglelow-costenclosureandstillmain-
tain a more uniform sound distribution. Figure 2
showsasimilar room, butwithasomewhat longer
throw, where the EVI systems also perform very
well.Manyauditoriumsandtheatresaremuchwider
thanatypicalsetofchurchpews,soFigure6shows
afairlystandardauditoriumfloorplanandpossible
mountinglocations. Anyinterferencebetween the
systems will be concentrated in the center aisle,
wheresoundqualityisnot ascritical.The EVI-12,
EVI-15andEVI-28systemsarealsoidealfor re-
placingdistributedarrays, providing much more
uniformcoverageatalower cost. SeeFigure7for
isthat3dBoflong-throwSPLand1.5-2dBofside-
filllevelhasbeen lost.Ahigherresolutiondatafile
isneededtoprovidea“realworldrealistic”simula-
tion. Figure 5 shows the raw 2° polar data with
the averaged 10° datasuperimposed. Alsoshown
arefloorplansfromour 2° modeler, DCSO, the5-
degreeAcoustaCADDand 10-degree EASE. By
comparingthe2°,5°and10° resolutionyoucaneas-
ilysee the apparent loss in direct-field SPL. This
lossshowsupasaseriesof“steps”alongthelength
oftheroomandanartificiallynarrowedthrowwith
lessSPLinthecornersthanwouldbeachievedina
real-world installation. Please keep this in mind
whenusingsimulationsoftware.
HangingEVISystems:
For the EVI-12 and EVI-15 the physical
mountingofthesystemshavebeendesignedtobe
aseasyaspossible,withtwosimpleoptionsavail-
able. By far, the easiest solution is to use the op-
tional sturdy, cost effective EVI-12MB or
EVI-15MB U-Brackets that mount to the 3/8-16
T-nutlocationsonthesidesoftheenclosure.Thesup-
pliedforged-shouldereyeboltmustbeusedinthet-nut
location on the lower back side of the system as a
pull-uppoint(seefigure13).Withthisarrangement,
the U-Bracket holds approximately 80% of the
weight of the system, and the pull-up point pro-
videsaconvenientmethodof adjustingtheaiming
angle. The U-Brackets have easy-to-install bolt
patternsandincludethreesetsofOmniMount100
bolt patterns. For most applications, this will be
thepreferredmethodologyasitisfast,aesthetically
pleasing,flexibleandinexpensive. However, this
methodwillnotworkinallapplications,sowehave
includedasecond setofT-nut locationsonthetop
oftheenclosuresothatthehangingcables can be
completelyoutofviewfrombelow(seeFigure14).
Thefront pair of hanging points should carry ap-
proximately50lbs oftheenclosure’s weight,with
the required pull-up point taking the balance of
the weight (about 5 lb). The T-nut locations are
intended to be used only with forged shoulder
eyeboltswithaminimumtensilestrengthof350kg
(770lb). The inexpensiveEBK-1kitincludesthree
eyebolts,especiallyhelpfulwhenaccess toquality
forgedshoulder eyeboltsislimited. Pleasekeepin
mind that the center of gravity is designed to be
behindthemainhangingpoints. Thismeansthat
the back of the system will rotate as much as 50
degreesdown,allowingeasy aimingadjustmentto
virtuallyanyangle.
5

6
NOTE:Allfiguresaredirect-fieldSPLandC50producedinEASEwithinterferenceturned
on whenapplicable. All plots depict the intended listening areas only, and do not includethe
“offset distance” to the first row. For example, the first set of plots on figure 3 depict the same
54’ x 36’ area as figure 1. See notes on simulation software.
Figure1
DirectFieldSPL C50
anideaonhowthesameauditoriumfloorplancould
beeasilycovered inasurround-stylearrangement
withjust twoEVIsystemsperside ratherthanfour
distributedarrays. Althoughnotprovidingthehigh-
estintelligibilityorsmoothest response,itisappli-
cable to cinemas and some musical preferences.
Thishastheadvantagesofcuttinginstallationtime,
amplifierchannels,additionaldelaylinesandatthe
sametime providingsuperiorcoverage.
Agymnasiumisanotherperfectapplication
fortheEVIsystems,coveringeachgrandstandfrom
apairofcentrallylocated EVIsystems(see Figure
8). In addition, you can cover the entire gymna-
siumfromeitherasinglelengthwise-orientedsys-
tem or with a pair of widthwise-spaced systems
with lower-SPL coverage on the floor of the
gymnasium than in the stands, so the players are
notdisturbedby announcements(seeFigure 9).
When the EVI-12 and EVI-15 systems are
tiltedup approximately15°,theircoveragepattern
lengthens to match a level EVI-28 at 5 times the
height. Insuchcasesthesystemsworkverywellto
replaceadistributedsystemalongaverylong,fairly
wide corridor where very high SPLs are not
requiredonacontinuousbasis(such as an airport
concourse with 15 to 20 foot ceilings, where a
speakerwouldbeplacedabout every75feet). See
Figure10 forapproximatemountinglocationsand
floorplancoverage.
These are but a few of the widely varied
applicationswhere the new EVI-12, EVI-15 and
EVI-28systemswilleasily outperform aconven-
tionalsystem. Theextremelyuniform coverageof
thesystemsare fairlyinsensitiveto placement,re-
quireonlyafewsimplecalculationstofindthebest
mountinglocation,andtheaimingangleisnomore
orlesssensitivethana conventional loudspeaker.
This makes installation nearly foolproof. Even
installationinnon-optimalconditionswillproduce
remarkablyevencoverageandhighintelligibility.
Asquestionsarise,you may feelfreetocon-
tact us at 800/234-6831, or FAX at 616/695-1304.
EVI SYSTEM MOUNTED
AT 18’ HEIGHT AND
0°AIMING ANGLE
(TOP PARALLEL TO FLOOR)

Figure3
C50
DirectFieldSPL
C50
DirectFieldSPL
Figure2
C50
DirectFieldSPL
7
EVI SYSTEM MOUNTED
AT 18’ HEIGHT AND
+10°AIMING ANGLE
TILTED BACK
FROM FLOOR
CONVENTIONAL 60X40 SYSTEM
MOUNTED AT 18’ HEIGHT AND
AIMED ABOUT 30°DOWN
CONVENTIONAL 60X40 SYSTEM
MOUNTED AT 18’ HEIGHT AND
AIMED ABOUT 25°DOWN

8
AcoustaCADDTM Direct Field SPL
EASETM Direct Field SPL DCSO DirectFieldSPL
Vertical Polar
Raw
Smoothed
Figure4 Figure5
HorizontalPolar
DirectFieldSPL
Raw
Smoothed

Figure6
9
C50
DirectFieldSPL
EVI SYSTEM MOUNTED
AT 20’ HEIGHT AND
8°AIMING ANGLE

Figure7
10
C50
DirectFieldSPL
EVI SYSTEM MOUNTED
AT 18’ HEIGHT AND
-10° AIMING ANGLE
EVI SYSTEM MOUNTED
AT 22’ HEIGHT AND
-10° AIMING ANGLE

Figure8
11
C50
DirectFieldSPL
EVI SYSTEM MOUNTED
BACK-TO-BACK
AT 30’ HEIGHT AND
+5°AIMING ANGLE

Figure9
12
C50
DirectFieldSPL
EVI SYSTEM MOUNTED
AT 25’ HEIGHT AND
15°AIMING ANGLE

Figure10
13
C50
DirectFieldSPL
2 EVI SYSTEM MOUNTED
BACK-TO-BACK AT 40’ HEIGHT
AND +10°AIMING ANGLE

PartNumber534762—9822
Figure14
Figure13
Figure15
600 Cecil Street, Buchanan, MI 49107
800/234-6831, 616/695-6831, 616/695-1304 Fax
©Telex Communications, Inc. 1998 • Litho in U.S.A.
BOLTS AND CABLING/CHAINS MUST
BE RATED FOR OVERHEAD LIFTING
(NOT SUPPLIED)
BOLTS AND CABLING/CHAINS MUST
BE RATED FOR OVERHEAD LIFTING
(SEE TEXT)
3/8-16 FORGED SHOULDER
EYEBOLT (SUPPLIED) WITH
PULL-UP STRAP
PULL-UP STRAP
ATTACHED TO 3/8-16
FORGED SHOULDER
EYEBOLT (SEE TEXT)
Figure11
Figure12