inboardside
of
Iheirrespectivebassunits.
If
Iheloudspeakersystemis
to
havelow.midrangeandhighfrequencycomponents,placingthemin
a
verticalline(low,midandhigh)willgenerallyprovidewidestandmost
uniformsounddistributionwithinthelisteningroom.Forbestacoustics,
componentsshouldbeasclosetogetheraspractical,butalleast50mm
(2in)aparttomaintainthestructuralintegrity
of
thebafflepanel
Positioningthehighfrequencydrivernear,ordirectingitsoutputtoward,
listenerearlevelwillusuallyresultinthemostrealisticperformance.
Caution:
Topreventseriousdamage,neverconnecta midrange
or
high
frequencytransducerdirectlyloanysourcecapableofgeneratinglow
frequencysignals.Connectionshouldbemadeonlytotherespectivemid
orhighfrequencyterminals
of
therecommendedJBLfrequencydividing
network.
If
separateamplifiersareusedforthevariouscomponents
of
the
system(bi-amplification
or
tri-amplification).
a
properlydesignedhigh-pass
filtermustbeused-inadditiontoanelectronicfrequencydividingnetwork
-toprotectthetransducerfromturn-ontransientsandotheraccidental
lowfrequencysignals.
LE5H
Midrange
Transducer
TheLE5Hmustbehousedinanisolated
sub-chambertopreventinteractionwiththelowfrequencyloudspeaker.
Forsmoothestfrequencyresponsethesub-chambershouldhave
a
minimumvolume
of
1.3litres(80
in3),
andshouldbefilled
lo
moderate
densitywithfiberglassacousticdamping
material.
A sub-chambercan
be
fabricatedof
a
tubehavinganinternaldiameter
of
114mm
(4
ft
in)and
a
length
of
130mm(5in)flushmountedonthebafflepanelandclosedat
itsinteriorend.Inserttheinpulleadsthrough
a
smallholepunched
in
the
side
of
thetube(usecaulkingcompoundtomaintainanairtightseal),and
installthedampingmaterial.Pressthetubularvinylgaskelintothegroove
ontheback
of
themountingflange,connecttheinput
leads,
placetheLE5H
intothetubeandsecure
it
tothebafflepanelwiththefourself-tapping
screwsprovided.
LE21H
HighFrequencyDirectRadiator
TheLE21Hmountsdirectly
to
thefront
of
thebafflepanelusingT-nutsandmachinescrewsThecutout
should
be
105mm[AM in)indiameter,withadditionalclearanceprovided
fortheterminals(seethediagramonthenextpage).Theflatgasketonthe
rear
of
themountingflangewillformanairtight
seal.
PlacetheLE21H
in
themountingcutoutandlightenthescrewsa littleat
a
time,maintaining
evenpressureonthegasket.Donotovertighten,
075And077
The075and077mountfromtherear
of
thebafflepanel
in
an81mm(3?i«in)diametercutout:thedriverisheldinplacebyfour
machinescrewsextendingthroughthebafflepanel.Placethetubularvinyl
gasketaroundthehornandseat
it
againstthemountingbracketprior
to
insertingtheunitintothebafflecutout.NOTE:The077shouldbemounted
withtheslot
vortical,
asshown,toprovidemaximumhorizontaldispersion.
The075producesa conicalsounddistributionpatternandneedsnopar-
ticularmountingorientation
