Ramsa WS-A550-K User manual

•
RAMSri
SPEAKERSYSTEM
WS-A500-K
WS-A550-K
(DarkGrey)
WS-A500-W
WS-A550-W
(White)
Operating
~z; : Instructions
Panasonic
Beforeattemptingtoconnectoroperatethisproduct,
pleasereadtheseinstructionscompletely.
CONTENTS
CAUTIONSFORINSTALLATION1
GENERAL2
CONNECTIONOFSPEAKERCABLES9
CAUTIONSFORCONNECTION 11
PRECAUTIONS 11
TYPICALAPPLICATIONS 11
WS-SP2ABLOCKDIAGRAM 12
TYPICALSYSTEMPERFORMANCE12
SPECIFICATIONS13
APPEARANCE14

CAUTIONSFORINSTALLATION
ThemoldedresinenclosureoftheWS-A550islightinweightandhighlydurable.Aswithanycabinetloudspeakersystem,however,
certaininstallationprecautionsarenecessarytoassurepublicsafety/maintainproductappearanceandobtaingoodsoundquality.
MountingofLoudspeakers UseoftheStackingFeature
TheWS-A500andWS-A550areequippedwith(8)M-8
threadedinserts,twopersideformountingpurposes.When
used ¡n pairs,theinsertswillsupportthespeakerata minimum
designfactorof40:1(Baseduponin-linelaboratorytensile
pulltestsbyNationalTechnicalSystems,dataonfile).When
mountingthespeakerstothethreadedinserts:
•Whenmountingtheloudspeakersystemtoa wallor
ceiling, alwayssecurethemountinghardwaretobuilding
structuralmembersthatarecapableofsafelysupporting
notlessthan (10) timestheactualweighttobesuspended.
Never attach tothesurfaceofa wallorcelling.
•Neverassumethestrengthofhiddenstructuralmembers.
Hiddenstructuresmayalsohavehiddenweaknesses.
Whenindoubt,obtaincompetentadvicefroman
architectorlicensedmechanicalengineer.
•A chainisonlyasstrongasitsweakestlink.Neveruselag
screwsoreyesthatrelyuponwoodenthreadsforsupport;
neveruse S-hooks, J-hooksorformedeyebolts,asthese
attachmentscanpullopenunderloading.
Thecabinetsfeatureinterlockingribstofacilitatestacking
ofmultiplespeakersystems.Whenstackingloudspeaker
systems:
•Alwaysselecta flat, smooth, floor orgroundsurfaceupon
whichtostackthespeakers.Donotstackspeakerson
anirregularsurface;neverstackspeakersona surface
orobjectthatisabovethefloororground,suchasupon
tables,boxes,orspeakerstands.
•Arrangeloudspeakerstackssothattheinterlockingribs
areinproperalignment(allcomponentsorientedthesame
direction)topreventcabinetsfromsliding.
•Donotstackspeakerstoa heightgreaterthan4 ftabove
the floor orgroundwithoutprovidingadditionalsupportto
preventtoppling,shouldthespeakerstackbeaccidentally
bumped. Alwayssecurelargestackedarraystoprevent
accidents.
EnvironmentalConsiderations
•TwoM-8treadedinserts(eye-bolt,bolt-nutsandwasher)
areprovidedfortheWS-A500/550speakerforfastening
themountingbrackettothespeaker.
Forstandmounting,twoeye-boltsshouldbe
hand-tightenedonlyasshownin Fig.1.
Tousethespeakersuspended,usetwoeye-boltsper
speakeralongwiththebolt-nutsandwashers(provided).
Eye-boltsmustfirstbehandtightened.
Thenafteradjustingtheeye-boltdirection,tightenthe
bolt-nutsfirmlyusingwrenchasshowninFig.2inorderto
securethespeaker.
Mounting
oracket
Setdirection(2)
Handtighten 12}
Bolt-nut
Insert(11Hand
tighten(1)
33»
Eye-bolt
Tightenwith
wrench(3)
n
(Fig. 1 ) (Fig.2)
Themoldedresinenclosureishighlydurable,and resistant to
mostdamage,suchasabrasion.Tomaintainappearanceand
assurecontinuedperformance:
•Protecttheenclosurefromenvironmentalextremes.
Shelterthecabinetfromdirectsunlighttopreventcolour
fadingandpossiblelong-termdeteriorationfromUV
radiation.
•Donotexposethespeakercomponentstodirectrain
ormoisture.Excessivemoisturecandamagethecone
transducer,andincertainenvironments,moisture-born
particulatesmaycontaminatethemetalpartsandthe
voicecoilgapswithprolongedexposure.
•Donotmountthespeakerincloseproximitytoheatingor
airconditioningoutletsand/orequipment.
Maintenance
•Wipetheenclosureregularly,usinga soft,drycloth,or
aclothmoistenedwitha solutionofwaterandnormal
kitchendetergent.Donotusechemicalsforcleaningthe
enclosure,assomechemicalsmaydamagethesurface.
•Donotdisassembletheloudspeakersystem,orremove
thefrontgrillscreen.Therearenouserserviceable
componentswithin. If repairsareneeded,contacta local
AuthorizedPanasonicServiceCenter.

GENERAL
PowerCapacityRatings LoudspeakerLimitationsandFailureModes
Becausethereareno'standard'musicalprogramswithwhich
totestthepowercapacityofa loudspeaker,laboratoryrating
methodshavebeen developed. Thepurposeofpowercapacity
ratingsistwo-fold:toprovidea repeatable, Industry-standard
basisforcomparisons,andtoachievea ratingmethodthat
isrepresentativeofactual-useconditions.Standardtest
signalsarerepeatable,andprovideforreliablecomparative
measurements,buttestsignalevolvedtosimulate'typical'
audioprogramscannotemulatetypicalaudioprogramsor
conditionsofusebydefinition.Powercapacityratingsare
notabsolute,whentheprogrammaterialisotherthanthe
testsignalusedfortherating.Knowledgeofthepower
capacityratingmethodandofpracticalloudspeakerlimitations
canpreventunforeseenfailures,rewardingtheinformedwith
yearsoftrouble-freeproductuse.
Thepowerratingmethodusedforthe WS^A500 andWS-A550
isasprescribedby EIA (ElectronicIndustriesAssociation)
RS-426-A(1980).Thetestsignalisshapedrandomnoise,
witha 4:1(6dB)peaktoaveragecontent.Thetestsignal
concentratesmostoftheenergyinthemiddlefrequencies,
whileattenuatingthelowsandhighs.Thecombinationofthe
filtercharacteristicandthatofwhitenoise— thespectral
energyofthetestsignal— iswhatneedstobeinFigure1.
0
-5
10
-15
20
25
in
2
20Hz 34 5 67891 23
200Hz 45 67891
Frequency
2
2kHz 34
5 67891 2
20kHz
SpectralEnergyofGaussianNoise,Shapedby
ElectronicsIndustriesAssociation(EIA)RS-426A(1980)
FilterCharacteristic
(Fig. 1)
Dynamicloudspeakers,includingcompressiondrivers,consist
ofa diaphragmattachedtoa voice coll thatissuspendedina
magnetic field that is focusedacross anairgap in themagnetic
structure.Compliantsuspensionelementscenterthevoicecoil
intheairgap,whileallowingthediaphragmtomoveoutward
andinwardinresponsetoalternating(audio)currentsthat
aresuppliedtothevoicecoilfroma poweramplifier.These
componentsareshowninFigure2.
Outer
Suspension
Diaphragm
DustCap
Frame
BackPlate
TopPlate
MagneticGap
VoiceCoil
VentHole
PolePiece
Center
Suspension
Magnet
VoiceCoilFormer
Gasket
(Fig. 2)
RAMSAtransducersareconservativelyrated,bothintheir
performancecharacteristicsandpowerhandling.Aswith
anytransducersystemintendedforprofessionaluse,the
hazardsaremany,andfieldfailuresarepossible.Failures
duetodefectivematerialsand/orworkmanshipareeasily
identified, andwillbepromptlyrectifiedwithinthetermsofthe
productwarranty.Failuresresultingfromexceedingtransducer
limitationscanbeeasilyprevented,oncetheoperatinglimits
areunderstood.
Therearetwodistincttypesoftransducerfailures: those
thatoccurfromexceedingthethermalpowercapacityof
thedevice,andthosethatresultinmechanicaldamagefrom
diaphragmover-excursion.

ThermalPowerLimits
Thevoice colls ofRAMSAprofessionalloudspeakersare
designedtooperateatvery high temperaturesbeforerisk
ofa 'burnout'failure.However,Itisusefultorememberthat
thevastmajorityofthepowerina loudspeakerIsconvertedto
heat,withonlya smallpercentageoftheenergyconvertedinto
acousticpower.Becausethevoicecoilisoperatinginanair
gap, preciouslittleheatIsconductedawaythroughthecone
andsuspensionelements.Someoftheheatisradiatedtothe
transducer'smetalparts,butthemajorityofthecoolingcomes
fromaircirculation.
Theoutwardandinwardmovementofthediaphragmcreates
airmovementtocoolthevoice coil, withoutwhichthecoil
wouldbesubjecttogreaterheatingandprematurethermal
failure. TheEIARS-426Atestsignalcontainssufficientlow
frequencyinformationtocreateairmovementacrossthevoice
coilthatistypicalofprogrammaterialuseconditions,but
theweightingprecludeshighpoweratlowfrequenciesthat
could induce mechanicalfailuresbyexceedingtransducer
displacementlimits.PowerratingsbasedupontheEIA
RS-426Aratingmethodare,therefore,appropriatethermal
powerlimitsforprogramuseconditions.
BoththeWS-A500(operatedwithitsinternalpassive
crossover)andWS-A550caneasilysustaintheir(RS-426A)
thermalratedpower,butcanbedamagedbyexceeding
mechanicaldisplacementlimits(currently,thereareno
displacement-limitedpowercapacityratingmethods).When
theWS-A500Is bi-amplified, specialprecautionsare
necessarytoprotecttheHFtransducerfromdamage.
MechanicalPowerLimits
Aloudspeakerimpartssoundpressuretotheair,alternately
compressingandrarefyingbyoutwardandinwarddiaphragm
movementforeachHzofaudioinformation.(OneHertzis
acompletecycleofdiaphragmmovement,beginningfromrest
positiontotheoutwardpeak,returningthroughtherestposition
totheinwardpeak,andfinallyreturningoutwardtotherest
position.)Therateatwhichthediaphragmcompletescyclesis
thefrequency,whiletheenergyproducedisproportionaltothe
productoffrequencysquaredanddiaphragmdisplacement.
Forconstantfrequency-energyoutput (flat powerresponse),
direct-radiatingdiaphragmsmustquadruple In displacement
foreachhalvingoffrequency.
Alltransducershavemechanicaldiaphragmdisplacement
limits. Dependinguponthetransducer'sdesign,thelimitsare
reachedwhenthevoicecoilisdrivenoutofthemagnetic
field, orwhenthesuspensioncannolongerstretchto
allowdiaphragmmovement.Intheformercase,thedriving
electromagneticforcediminishesasthevoice coll beginsto
leavetheairgap.Undertheconditions,it Is unlikelythatthe
transducerwouldbeeasilydamagedthroughover-excursion,
asthedrivingforceIsreducedbeforethesuspensionlimitsare
reached. TheLFtransducerofthemodelWS-A500isofthis
type.
Withotherdesignapproaches,theavailablevoicecoiltravel
andelectromotivestrengthcanbesufficienttoexertdamaging
forcesuponthesuspensioncomponents.Transducers
intendedforextendedbassorsubwooferapplications
generallyfeatureverylongvoicecoilsandhighdynamicforces
toenablelargevolumedisplacement.Withthese'long-throw'
devices,physicaldamageispossibleatelectricalpowerlevels
thatarelessthanthethermalpowercapacityratingofthe
speaker,dependinguponthe frequency-magnitude oftheaudio
signal. ThetransducerintheWS-A550subwoofersystemis
typicalofa classofdeviceswiththesecharacteristics.
SignalProcessingRequirements
TheWS-A500andWS-A550loudspeakersystemsare
capableofhighperformanceindemandingprofessional-use
application.Bothsystemsarehighly-specializeddevices,and
havebeenoptimizedforoperationwithinspecificfrequency
ranges.Toachieveoptimalperformance,theWS-A500and
WS-A550shouldbeusedwiththeRAMSAmodelWS-SP2A,
whichprovidesband-passsignalprocessingforbothspeaker
systems.
TheWS-SP2Ainstallsbetweenthemixerandthepower
amplifiers,providingstereo Inputs, a summedsubwoofer
output,stereohigh-passedoutputsfortwochannelsof
mainloudspeakersandsummed(mono)full-rangeoutput.
ThesubwooferprocessorprovidesWS-A550systemsan
electrically-assistedalignmentandhigh-passprotectionto
enableoperationtoa —3dBfrequencyof35Hz.Three
subwooferlow-pass frequencies (50Hz,80Hzand 125 Hz)are
available,along with complementarystereosignalprocessing
theWS-A500.
AllfilterswithintheWS-SP2Aarefourth-order(24dB/octave)
Besseltype,whichhavea transfercharacteristicthathasno
offshootorringing,andcompletefreedomfromoscillatory
instabilities.Theinternalgainsarestructuredforequal
power-instabilities.Theinternalgainsarestructuredforequal
power-band-passcharacteristicsateachoutput.Figure3
diagramsthesignal flow oftheWS-SP2A.
8^o
i Processc
Sei
^M§)
Œ
©
X
d dB dii
soon uNBAi
20MlBAL
-T>M§)
©
EFJ
>*
PinConned
LFOutput
Gnd
Pin 2 Hot
6001)UNBAL
Pin3 - Cold
r>-<§)
fycm
©
B Outp
4dB
"^0
Func 6000
UNBAL
Inrjuf B <
Selec
V-®
m
©
B OutputB
B
4 dB
20 kit SAL
600(1UNBAL
WS-SP2ASignalFlow
(Fig. 3)
-3-

TheWS-SP2Ahasbalancedinstrumentationtype
inputamplifiers,withexcellentcommon-moderejection
characteristics.Theinternalgainshavebeencarefully
structuredtopreserveoperatingheadroomthroughout, with
amaximuminputlevelof+20dBv.A 3-5seconddelayed
turn-on, instant-offfeatureallowsthecircuitryintheWS-SP2A
tostabilizeafterenergizing,beforetheoutputsareconnected.
WS-A500Full-RangePowerCapacity
ThesafepoweroperatingrangeoftheWS-A500 Is shownin
Figure4.Thechartshowsaveragepowerontheright,anda
correspondingpeakvoltageontheleft.PeakInputvoltages
threatenthetransducer'smechanicaldisplacement limits, while
thermallimitsareaffectedbytheaveragepowerinthesystem.
WS-A500 System
ThermalandDisplacement-Limited
PowerCapacities
System
Thermal
Limits
System
Displacement
f
Limits
56 7 891 56
7 891
Frequency
(Fig. 4)
WS-A500 Bi-amplified PowerCapacity
WhentheWS-A500Is bi-amplified, attentionmustbegivento
theindividualpowercapacitiesoftheLFandHFtransducers.
ThesafepoweroperatingrangesoftheLFand HF transducers
areshowninFigure6.TheshapeoftheLFtransducer
displacementlimitlineisduetothedisplacementreduction
causedbythesystemporting.TheWS-SP2Aisrecommended
forLFtransducerhigh-passsignalprocessing.Withthe
WS-SP2A,theLFtransducerdisplacementlimitswillbeas
showninFigure5.
WS-ASOOComponent
ThermalandDisplacement-Limited
PowerCapacities
LFandHF
Thermal
Limits
HF
Displacement
Limits
Displacement
45 6 7 891 56 7 891 56
7 891
2kHz
Frequency
(Fig. 6)
Athighfrequencies,thethermalpowercapacityisreduced
dueto a reductionincoolingfromdiaphragmmovementin
bothtransducers.TheHFtransducerlimitsshownincludethe
lossofthe Internal attenuatornetwork.Thedisplacement-limit
linefortheHFtransducersteepensbelowtherecommended
crossoverfrequency,asthepattern-controlhornunloads.
FromFigure 4, theWS-A500willbelimitedinoveralloutput
capabilitybythelowfrequencydisplacementlimits.Where
programcontenthasnoenergybelow 100 Hz, asinvocal-only
soundreinforcement application, theWS-A500needsnosignal
processing.High-levelapplicationsthatcontainenergybelow
100Hz willrequirethe WS-SP2A, whichwillprovideband-pass
protectionfortheWS-A500andenablehigheroverallsound
levels.Figure5 showstheWS-A500powercapacitywiththe
WS-SP2A
Safeoperationwillberealizedbelowandtotherightofthe
respectivethermalanddisplacementlimits.Notethatitis
possibletoexceedthemechanicaldisplacementlimitations
wellbelowthethermalpowercapacitiesofboth transducers,
whiletheLFtransducerintheWS-A500maybesomewhat
forgivingoftheseabuses,theHFcompressiondriverisless
likelytobe.
WS-ASOO System withWS-SP2A
ThermalandDisplacement-Limited
PowerCapacities
Displacement
Limits with
WS-SP2A
System
Thermal
Limits
56 7 8
RecommendedElectronicCrossoverCharacteristics
Therecommendedelectroniccrossoverisa fourth-order(24
dBper octave), LinkwitzorBessel type, witha —6 dBcrossover
at 1.5 kHz.Othercrossoverslopesandlossesatthecrossover
frequencycanresultinvaryingresponsediscontinuitiesand
polarlobingerrorsinthecrossoverregion.
Frequency
(Fig. 5)
-4-

WS-A550PowerCapacity
PowerCapacityRating
LiketheWS-A500,theWS-A550isratedinaccordance
withEIARS-426A,witha thermalpowercapacityof400
watts. WS-A550systems require thesignalprocessingofthe
WS-SP2Aforproperoperation.Theymustalsobeoperated
with careandunderstandingoftheirlimitations.Figure7 plots
thethermalanddisplacementlimitsofsafeoperationfora
singleWS-A550whenusedwiththeWS-SP2A.
WS-A550SystemwithWS-SP2A
ThermalandDisplacement-Limited
PowerCapacities
1000
500
250
125
63
32
16
8
>
a.
118
Hll
b/
40
•;H
20
14
10
7.
h
H.h
Vh
II I I I II
s
System
Thermal
Limits
>
r
0
m m
A
• C
,f
J
f
.
i
J
I
i
/
f
f—
)'
Displacement
Limitswith
WS-SP2A
'
23 4 5 6 7 891
20Hz
Frequency
(Fig. 7)
2
1
0.5
2
200 Hz
HumanHearingCriteriaandPerformanceExportations
Fromreadingperformancespecifications,s singleWS-A550
iscapableofimpressiveoutputatsubwooferfrequencies.
Humanloudnessperceptioncomesintoplay,however,andthe
resultscanfallshortofexpectationswhenthesefactorsaren't
thoughtfullyconsideredandunderstood.Whenthishappens,
itIsverylikelythattheloudspeakerswillalsobeoperated
beyondtheirlimitsforsafeoperation.
Humanhearingisleastsensitiveatverylow frequencies. Figure
8illustratestheupperrangeofRobinson-Dadsoncriteriafor
equalloudnessperception.Thedatashowsa 30Hzsoundat
120 dBSPLtobeperceivedasequalinloudnessto 10OdB SPL
at 1 kHz.Becausetheacousticoutputofa subwoofersystem
isalmostalwaysbalancedwiththeacousticoutputofthe
mainloudspeakersbyear,thesecriteriaprovideanaccurate
Indication oftypicalperformanceexpectations,andshouldbe
usedasa guideforplanningofsubwoofersystems.
70
10
00
90
80
70
60
50
1III
LOUDNESS
120LEVEL(PHON)
110
100
_90
J»
.70
60
50
2 3 4 5 6 7891
20Hz
3 4 5 6 7 891
Frequency
23 4 5 6 7 891 2
2kHz20kHz
(Fig. 8)
UseInSystems
Figure9 showsthe1 metermaximumSPLvs.frequency
capabilitiesofa singleWS-A550,consideringmechanical
displacementlimitsalone.Everythingtotherightofthe
displacementlimitlineiswithinthecapabilitiesoftheWS-A550,
whileoperationtotheleftispotentiallyhazardous.Whenwe
considerhumanloudnessperceptioncriteria,thecapabilities
ofoneWS-A550appearfarremovedfromexpectations.
WS-A550
MaximumDisplacement-Limited
SPLat1 metervs.Frequency
120
115
110.
E
•-
•105.
_l
a
IS)
T3 100
95_
90 _
23 4 5 6 7 8912
20Hz200Hz
Frequency
(Fig. 9)
-5-

TheWS-A550isintendedtobeusedasa modular
componentinsubwooferarrays.BecauseoftheWS-A550's
diminutivesize,a largequantityofmodulescanbeplaced
incloseproximitytoone-another,andtheiroutputswillsum
coherentlyatsubwooferfrequencies.Fortunately,when
multipleWS-A550Sareusedincoherentsubwooferarrays,the
performancecapabilitieschangedramatically(see'Subwoofer
Arrays').
Forsmallsystemplanningpurposes,thefollowing
rule-of-thumb guidelinesshouldbeobserved:
•Forwide-rangesoundreinforcementorplayback
applications,thesubwoofersystemshouldbecapableof
20dBgreateracousticoutputthantheaverageoperating
levelsofthemainloudspeakers.
•AlwaysusetheWS-SP2AwithWS-A550s.Withoutthe
WS-SP2A, thedisplacementlimitsoftheWS-A550willbe
easilyexceeded.NeveroperatetheWS-A550withoutthe
WS-SP2A,oruseanothermakeofsubwooferprocessor.
•Whenusedwitha pairof RAMSA modelWS-A500
loudspeakersystems,between4 and8 modelWS-A550
subwoofermodulesWS-A550willbeneeded,depending
upontheverylowfrequencyprogramcontent.
•Whenusedwitha pairof RAMSA modelWS-A80
loudspeakersystems,between2 and4 modelWS-A550
subwoofermoduleswillprovideanappropriatebalance,
dependingupontheverylowfrequencyprogramcontent.
•Carefullyconsiderthemechanicaldisplacementlimits
oftheWS-A550.Insmallarrays,thetransducer
displacementlimitswillrestrictthemaximumacoustic
outputwellbeforereachingthethermalpowercapacity
ofthearray.Damagefromdiaphragmover-excursionis
likelytooccurwhenaninadequatenumberofsubwoofer
modulesareprovidedfortheapplication.
Source-inducedFailurePrecautions
Loudspeakersystemscanbeexposedtoseveralpotentially
hazardousnon-programsignalsinprofessionaluse.Some
ofthesesignalsareoutsideoftheaudiofrequencyrange,
andrepresentspecialconditionsforwhichthepowerratings
don'tapply.Careshouldbetakentoassurethatloudspeaker
systemsaren'tsubjectedtothesesignals.
•UltrasonicandRFoscillations— veryhighfrequency
(inaudible)electricalenergyathighpowercanrapidlyheat
voicecoilstothefailurepoint.Becausethereislittleorno
diaphragmmovementwithRFenergy,therewillbelittleor
nocoolingairmovement,andvoicecoilscanbeexpected
tofailatlessthenrated(audiofrequency)power.
•High-speedtapenoise— Someanalogaudiotape
machinesallowfastforwardorrewindoperationswith
thetapeincontactwiththeheads.Thiswillresultin
excessivehighfrequencyenergywhenconductedathigh
levels,whichcanbehazardoustotransducers.
•Acousticfeedback— especiallywhensustained.When
unchecked, acousticfeedbackwillgrowinintensityuntil
thepoweramplifier(s)arefullyclipped.Thisconditionis
almostcertaintoresultintransducerfailures.
•Turn-on/turn-offtransients— fromlow-levelaudio
equipment.Mostlow-levelaudioequipment(mixers,
equalizers,signalprocessing)haveoutputsthatare
unprotectedfrominternalturn-on/turn-offtransients,
andcansendseveralvoltsofswitchingnoise(including
DCandRF)tothepower amplifiers^) duringswitching.
Adoptinga last-on,first-offpolicyforthepower amplifiers
willprotecttransducersfromthesesignals.
•Connectionsanddisconnections— shouldalwaysbe
performedwithaudiolevelsdowntopreventshocknoise
or(worse)electricaloscillationscausedbygroundloops
orgroundinterruptions.
•Poorhousekeeping— cancreateunforeseenhazards.
Keepequipmentworkingareasfreefromcablesand
powercordsthatmaybetrippedoverand accldently
disconnected.
-6-

WS-A500DirectionalRadiationCharacteristics GeneralArrayRecommendations
Figure10, 11 : WS-A500
DI-DF/Frequency
-3dB,-6dB,-9dB,-12dB
RAMSAWS-A500
-3dB,-6dB,-9dBand-12dB
HorizontalCoveragevs.Frequency
360
100
80
70
60
50
46
40
35
30
?5
20
15
10
V---A
\
S» - = ">-\
V-- -^
\//r
\,J4
:;-::£
. sK.tz
f
^
-*
\
\
\
:*$::
-/-S--
Z---S.
-,v
.__..._.
\
23
200Hz 56 7 891
1kHz 56 7 8912 10kHz20kHz
Frequency
(Fig. 10A)
RAMSAWS-A500
-3dB,-6dB,-9dBand-12dB
VerticalCoveragevs.Frequency
am
?sn
?oo
ISO
100
90
80
70
60
50
4b
40
35
30
25
?0
15
S
\
s,
's,
\
v
<\
—-
v.
,
V
23
200Hz 45 6 7 891
1kHz 45 6 7 8912 10kHz20kHz
Frequency
(Fig. 10B)
RAMSAWS-A500
AxialDirectivity
-10
-ID
.0
23
200Hz 56 7 891 1kHz 67 8 9
1
10 kHz 2
20kHz
Frequency
(Fig. 11)
Thecompactsize,controlleddirectivityandhighperformance
oftheWS-A500makeitanidealcomponentforarrayuse
insoundreinforcementapplications.A detailedexamination
oftheperformanceofWS-A500sinvariousarraysis
beyondthescopeofthismanual,however,thefollowing
generalrecommendationsapplytobothlargeandsmallarray
applications.
•Minimizethequantityofloudspeakerswithineacharray.
Usenomoreloudspeakersystemsthannecessaryto
achievethedesiredSPLorcoveragegoals.Increasing
thearraysizewillincreaseSPL,butattheexpenseof
intelligibilityandtransientdetail.Itwillalwayssoundbetter
toreducetheoverallSPLexpectationsinfavorofa more
coherentarray,especiallyiftheprogramcontainshigh
frequencytransientdetails.
•Grouploudspeakersintightclusters.Whenthearrayis
small, comparedtothewavelength,thesoundpressure
radiatedbythecomponentswillsumcoherently,andthe
arraywillemulatea pointsource.However,whenthe
arrayislarge,comparedtothewavelength, Interference
betweenarraycomponentswillresultin'fingering'of
thepolarradiation,smearingofhighfrequencytransient
detailsanddiminishedhighfrequencyoutput.
•MinimizeCoverageOverlap.Loudspeakersthatoverlap in
coveragecreateinterferenceatshortwavelengths,with
reduced intelligibility andsmearingofhigh frequency detail.
•Increasedcoveragewillbesmoothestwhenloudspeaker
sourcesarestackedandsplayed,ratherthan
side-by-side.Whereinstallationconditionspreclude
usingstackandsplaytechniques,interferencebetween
side-by-sideWS-A500scanbeminimizedbyinverting
alternatecabinets.
Split-SourceandMulti-Channel(Stereo)Arrays
•Splitloudspeakersourcesarethenormalconfiguration
forentertainmentsystems.Manysplitsystemsarealso
beingmixedintwochannels,whichcanimproveauditory
perspectiveformostoftheaudience.Themostsuccessful
splitclusterarraysprovidecompletehousecoveragefrom
eachclusterlocation,andarenotwidelyseparated.
•Clusterseparationwillsetthewidthoftheapparent
soundstage,butshouldbekepttoa minimum,consistent
withthewidthoftheperformancearea,tominimizethe
propagationdelaybetweenclustersfortheaudience
seatedoff-center.
•Thenumberofchannelsisoptional.Excellentresultscan
beobtainedwiththreechannelsystems(left,center,right)
byspreadingtheinstruments,whilesendingvocalsand
intelligibility-demandingdetailtothecenterarrayonly.
Bydiscretelyaddressinga greaternumberofsmaller
(discrete)arrays,interferencewithinandbetweenclusters
willbe minlmlzed.while creatingthedesiredacoustic
energyandauditoryperspectivewithintheperformance
space.
•Signalroutingshouldprovideforanindependent
subwoofermixassignment,astherewillbea great
numberofsoundsthatshouldbeisolatedfromthe
subwoofers.DifferentInstrumentswillneeddifferent
subwooferequalization,aswellasdifferentmixlevels.
Bassandkickdrumneedverysubtlesubwooferbalancing
tonotbeoverpowering.Thisalsoenablespowerful
visceraleffectsandmusicalunderpinningstobecreated
withoutinterferingwithmoredelicateupperfrequency
detailsandtextures.

SubwooferArrays
MutualRadiationEffects
Multipledirectradiatorsystemswillbehaveasa single
loudspeaker,providingthearrayisoffinitedimensions
andallofthecomponentpartsvibrateinphaseandwith
identicalvelocityamplitudes.Undertheseconditions,the
volumedisplacementofthearrayisthesumofthevolume
displacementsofthecomponenttransducers.Figure12
dimensionsvariousarraysofWS-A550modulesandTable
Aliststheperformancecharacteristicsforeacharray
configuration,fromonetosixteenmodules.
O
oo
t
1-10
-2-7-
oo
OO
oo
-3-8-
SO
so
OS
OS
t
1-10
2-7
-3-8-
-7-3-
SO
so
so
so
OS
OS
OS
OS
5-3
SO
so
so
so
so
so
so
so
OS
OS
OS
OS
OS
OS
OS
OS
(Fig. 12)
Characteristic
PressureSensitivity
(1 w/1 m)
ArrayReference
Elliciency (halfspace)
Thermal Power
Capacity(EIA HS-426-A)
1m (equivalent)SPL al 1 dB
ThermalPowerCompression
-3dBLower
Frequency(hall space}
PistonBand
FrequencyLimit
VolumeDisplacement
(VD)
VOEquivalent
SPL@ 50Hz
PowerOutput,35Hz- 50Hz
(acouslicwatts)
NominalImpedance
(Combinations)
TotalVolume
(fortransport)
TotalWeight(kg)
QuantityofWS-A550ModulesinArray
1
91 dB
0.85%
400w
113 dB
35 Hz
400Hz
6.0 x 102 cm3
112 dB
1w
en
2.1 It3
16 kg
2
94 dB
1.7%
800 w
119 dB
34 Hz
170Hz
1.2x103cm3
118 dB
4w
40
2@sn
4.2 ft3
32kg
4
97 dB
3.4%
1.600 w
125 dB
32 Hz
125Hz
2.4x103cm3
124 dB
16 w
2£ï.
2@4Q
8.5 ft3
64kg
8
100 dB
6.8%
3.200 w
131 dB
30 Hz
75 Hz
4.8 x 103cm3
130 dB
64 w
2@2U,
4@4tl
17 ft3
128 kg
16
103 dB
13.6%
6.400 w
137 dB
28 Hz
50Hz
9.6 x 103cm3
136 dB
256 w
4@2£1.
a@4n
34 It3
256 kg
Theseperformancecharacteristicsareonlyvalidforcoherent
arrays,thatis,arrayswithinwhichalloftheradiating
transducerscanbecircumscribedbytheshortestwavelength
ofcoherentsummation.Thisistheindicatedupperfrequency
listedinTableA.Asthearraygetslarger,theupperfrequency
limitsmovedownward.
BoundaryConditions
Subwoofersystemsperformbestwhenconfiguredas
coherentarrays.Fora stagesettingtherearelimitedoptions.
Thefloor In frontofa stageeffectivelydoublesthesizeof
thearray.Therealloudspeakersareabovethefloor,while
asecondimaginarysetislocatedbelowthefloor,Figure
13showstherealandimaginarycomponents.Thesystem
willperformexactlyasthoughitwereanarrayconsistingof
thesumoftherealandimaginarycomponents.Thevolume
displacementwilldouble,therewillbea 6 dBincreasein
radiatedpower,andtheupperfrequencylimitsforcoherent
summationwilldecrease.Thethermalpowercapacitywill
remainthatoftherealsources,however.
GroundPlane
Imaginary
Sources
(Fig. 13)
Acornerlocationwillintroduceanotherboundary,effectively
re-doublingthearraysizefromthatofmid-roomfloor
placement.
Splitsubwooferarraysaretobediscouragedinlargespaces,
asthedirectenergyfromthearrayswillcreateinterferenceas
afunctionoffrequencyandobservationpoint.Foroutdoor
systemsandwideangleseating,splitsubwooferclusters
shouldnotbeemployed.
TableA
-8-

CONNECTIONOFSPEAKERCABLES
Whenconnectingtheinputcabletothespeaker,4 POLEconnectorNL4FCseriesmadebyNEUTRIKAGshouldbeused.
3
(1)Unscrewtheconnectorcapbyrotatingit counter-
clockwise.
(2)Slidethecableclampoutfromtherearoftheconnector.
(3)Separatetheconnectorsleevefromtheterminal block.
(4)Passtheconnectorcapandcableclampovertheendof
thecable.
(5)Loosentheclampingscrewsintheterminalblock.
(6)Prepareandinsertthewiresintotheappropriateterminals.
(7)Tightenthescrewtosecurethewires.
(8)Foraddedsecurityinportableapplications,solderingof
thewirestotheterminalsisrecommended.
(9)Engagethetangontheterminalblockwiththemating
grooveinthesleeveandslidethesleeveovertheterminal
blocktothestop.
(10)Drawthecableclampupthecableandrotate until
positionedtoengagethematinggroovesinthesleeve.
Slidethecableclampforwarduntilfullyseated.
(11) Securetheassemblybyscrewingtheconnectorcapon
(clockwiserotation).
Blockholder
Loosenthe
screw.
Cable
Tightenthescrew
Groove Solder
Engageandinsert
Insert
Blockholder
Cap
-9