FBT MPA 3240 User Manual [en, de, es, fr, it]

MPA3120

POWERAMPLIFIER

POWERAMPLIFIER

MPA3120

MPA3240

OUTPUTLEVEL

MPA3240

POWERAMPLIFIER

ZONE1 ZONE2 ZONE3 ALL

0 0

+10-10

BASS TREBLE MASTERVOLUME

ZONE1 ZONE2 ZONE3 ALL

0 0

+10-10

BASS TREBLE MASTERVOLUME

+10-10 100

+10-10

Istruzioniperl’uso

Instructionsforuse

POWER

OUTPUTLEVEL

POWER

Manueld’utilisation

Gebrauchsanleitung

Gebruiksaanwijzing

Instruccionesdeempleo

LaFBTsiriservaildirittodiapportaremodificheaidisegnieallecaratteristichetecnicheinqualsiasimomentoesenzapreavviso.

FBTreservetherighttomakechangestothedrawingsandtechnicalspecificationsatanytimeandwithoutnotice.

FBTseréserveledroitd’apporterdesmodificationsauxdessinsetcaractéristiquestechniquesàtoutinstantetsanspréavisaucun

FBTdasRechtvor,jederzeitundohneVorankündigungÄnderungenantechnischenZeichnungenund-Merkmalenvorzunehmem.

FBTbehoudtzijzichhetrechtvooropiedermomentzondervoorberichtdetekeningenentechnischeeigenschappenaan wijzigen

teonderwerpen.

FBTsereservaelderechodemodificarlosdibujosylascaracterísticastécnicassinpreavisoalguno.

1

TABLEOFCONTENTSSOMMARIO

SOMMAIRE

1.Descrizionegenerale

1.1Pannellofrontale ..............................3

1.2Pannelloposteriore ..........................3

2.Avvertenzegenerali

2.1Installazione ....................................4

2.2Alimentazione ...................................4

2.3Notedisicurezza ..............................4

3.Connessioni

3.1Criterigenerali .................................5

3.2Ingresso/uscitadilinea ....................5

3.3Ingressotelefonico ..........................5

3.4Uscita‘MusicOnHold’(MOH)............6

3.5Precedenzaesegnaledipreavviso6

3.6Uscitedipotenza .............................6

3.6.1Sistemiabassaimpedenza...............6

-Calcolodell’impedenza

neicollegamentiinserie .................7

-Calcolodell’impedenza

neicollegamentiinparallelo ............7

3.6.2Sistemiatensionecostante ..............7

-Calcolodelnumero

didiffusori(tramitelepotenze) ......7

-Calcolodelnumero
didiffusori(tramiteleimpedenze)..8

3.7Selezionedizoned’ascolto...............8

1.Generaldescription

1.1Frontpanel ......................................3

1.2Rearpanel .......................................3

2.Generalwarnings

2.1Installation .......................................4

2.2Powersupply ...................................4

2.3Safetynotes ....................................4

3.Connections

3.1Generalfeatures ..............................5

3.2Lineinput/output .............................5

3.3Telephoneinput ...............................5

3.4’MusicOnHold’output(MOH)...........6

3.5Priorityandwarningsignal ...............6

3.6Poweroutputs .................................6

3.6.1Low-impedancesystems...................6

-Calculatingtheimpedance

valueinseriesconnections............7

-Calculatingtheimpedance

valueinparallelconnection ............7

3.6.2 Constantvoltagesystems ...............7

-Determiningthenumberof
speakers(throughpowervalues)..7

-Determiningthenumberof

speakers(throughimpedance).......8

3.7Selectingthelisteningareas .............8

1.Descriptiongénérale

1.1Panneaufrontal .............................11

1.2Panneaupostérieur .......................11

2.Précautionsgénérales

2.1Installation .....................................12

2.2Alimentation ...................................12

2.3Conseilsdesecurite .......................12

3.Connexions

3.1Criteresgeneraux ..........................13

3.2Entrée/sortiedeligne .....................13

3.3Entréetéléphonique .......................13

3.4Sortie‘MusicOnHold’(MOH)..........14

3.5Prioriteetsignald’annonce ............14

3.6Sortiesdepuissance ......................14

3.6.1Systèmesàbasseimpédance.........14

-Calculdel’impédancesur

lesbranchementsensérie...........15

-Calculdel’impédancesur

lesbranchementsenparallèle......15

3.6.2Systèmesàtensionconstante........15

-Calculdunombrede

diffuseurs(parlespuissances) .....15

-Calculdunombrede
diffuseurs(parlesimpedances)...16

3.7Selectiondezonesd’ecoute ...........16

4.Usodell’apparecchio

4.1Accensione ......................................9

4.2Controllodivolumeprincipale ...........9

4.3Correzioneacustica .........................9

-Controllotonibassi(BASS).............9

-Controllotoniacuti(TREBLE)..........9

4.4Sovraccaricoeprotezione ................9

5.Caratteristichetecniche ......... 10

4.Operation

4.1Poweron .........................................9

4.2Mastervolumecontrol ......................9

4.3Acousticadjustment .........................9

-Basscontrol(BASS) .......................9

-Treblecontrol(TREBLE) .................9

4.4Overloadingandprotection ..............9

5.Technicalspecifications .......... 10

4.Utilisationdel’appareil

4.1Miseenmarche ..............................17

4.2Controledevolumeprincipal ..........17

4.3Correctionacoustique ....................17

- Contrôle tonalité basses (BASS) . 17

- Contrôle tonalité aigues (TREBLE)17

4.4Surchargeetprotection .................17

5.Caractéristiquestechniques... 18

2

INHOUDINHALTSANGABE SUMARIO

1.AllgemeineBeschreibung

1.1Frontpaneel ...................................11

1.2Rückpaneel ....................................11

2.AllgemeineHinweise

2.1Installation .....................................12

2.2Einspeisung ....................................12

2.3Sicherheitsanweisungen .................12

3.Anschlüsse

3.1AllgemeineHinweise .......................13

3.2Leitungseingang/-ausgang .............13

3.3Telefoneingang ..............................13

3.4Ausgänge‘MusicOnHold’(MOH)....14

3.5Vorrangschaltungund

Vorankündigungssignal ...................14

3.6Leistungausgänge ..........................14

3.6.1SystemmitniedrigerImpedanz .......14

-BerechnungderImpedanz

beiReihenschaltungen .................15

-BerechnungderImpedanz

beiParallelschaltungen ................15

3.6.2SystememitkonstanterSpannung.15

-Berechnungderlautsprecheranzahl

(durchdieleistungen)...................15

-Berechnungderlautsprecheranzahl

(durchdieimpedanzen)................16

3.7AuswahlderKlangzone ..................16

1.Algemenebeschrijving

1.1Frontpaneel ...................................19

1.2Achterpaneel .................................19

2.Algemeneaanwijzingen

2.1Installatie ......................................20

2.2Voeding ..........................................20

2.3Opmerkingenoverdeveiligheid......20

3.Aansluitingen

3.1Algemenecriteria ...........................21

3.2Lijningang/uitgang..........................21

3.3Telefooningang ...............................21

3.4Uitgangen‘MusicOnHold’(MOH)....22

3.5Voorrangen

waarschuwingssignaal ....................22

3.6Vermogensuitgangen......................22

3.6.1Systemenmeteenlageimpedantie.22

-Berekeningvandeimpedantie

bijserieschakeling ........................23

-Berekeningvandeimpedantie

bijparallelschakeling ....................23

3.6.2 Constantespanningssystemen.......23

-Berekeningvanhetaantal

klankverspreiders(viadekracht).23

-Berekeningvanhetaantal

klankverspreiders(viadeimpedanties)24

3.7Selectievanluisterzones ................24

4.GebraüchdesGerates

4.1Einschalten ....................................17

4.2SteuerungderHauptlautstärke ......17

4.3Tonkorrektur ..................................17

-Tiefenkontrolle(BASS) .................17

-Kontrollehohetöne(TREBLE) ......17

4.4ÜberlastungundSchutz .................17

5.TechnischeEigenschaften ...... 18

4.Gebruikvanhetapparaat

4.1Aanzetten ......................................25

4.2Hoofdvolumeregeling .....................25

4.3Akoestischecorrectie .....................25

-Regelinglagetonen(BASS) .........25

-Regelinghogetonen(TREBLE) ....25

4.4Overbelastingenbeveiliging ..........25

5.Technischekenmerken ........... 26

3

GENERALDESCRIPTIONDESCRIZIONEGENERALE

12

OUTPUTLEVEL

1.1PANNELLOFRONTALE
[1] Selettoridellezone.
[2] Visualizzatoredellivellodiuscita.
[3] Spiad’accensione.
[4] Interruttoredirete.
[5] Controllodivolumegenerale.
[6] Controlliditono.

78111213910

8

1V1W GCOMHOT

ZONE1ZONE3ZONE2ALL

0

BASS

0

+1010

TREBLE

+1010

0

MASTERVOLUME

10

POWER

4563

1.1FRONTPANEL
[1] Zoneselectionswitches.
[2] Outputlevelindicator.
[3] ON/OFFsignallinglamp.
[4] Mainsswitch.
[5] Generalvolumecontrol.
[6] Tonecontrols.

Ω600Ω

LEV.LEV.

CHIME

FUSET2,5A

CONSUMPT.350W

CONSUMT.200W

MOHOUTPUTTEL

COMCOMCOMVINZ2Z3Z1

24VCOM50V70V100V

8Ω

1.2PANNELLOPOSTERIORE
[7] Selettoredellatensionedirete.
[8] RegolazionelivellouscitaMUSICONHOLD.
[9] Uscitedilineaedipotenza(1W/8 Ω)MUSICONHOLD.
[10] Ingressotelefonicobilanciato.
[11] Regolazionelivelloingressotelefonico.
[12]ChimeON/OFF.
[13] Morsettierapercontattodiprecedenza.
[14]Presadiaerazioneventoladiraffreddamento.
[15]Ingressodilinea.
[16]Uscitadilinea.
[17] Morsettieraperzoneselezionate.
[18] Morsettierauscitealtoparlanti.
[19]Morsettieraperalimentazioneesternaincorrentecontinua.
[20]Connessionetelaio.
[21]Spinadireteconfusibileincorporato.

OUTPUT

P

+

PRIORITY

INPUT

1416151718192021

1.2REARPANEL
[7] Mainsvoltageselectorswitch.
[8] MUSICONHOLDoutputleveladjustment.
[9] MUSICONHOLDlineandpoweroutputs(1W/8).Ω
[10] Balancedtelephoneinput.
[11] Telephoneinputleveladjustment.
[12]ChimeON/OFF.
[13] Terminalstripforprecedencecontact.
[14]Coolingfanairintake.
[15] Lineinput.
[16] Lineoutput.
[17] Terminalstripforselectedzones.
[18] Loudspeakeroutputterminalstrip.
[19]TerminalstripforexternalDCpowersupply.
[20]Frameconnection.
[21]Mainsplugwithbuilt-infuse.

4

GENERALWARNINGSAVVERTENZEGENERALI

2.1INSTALLAZIONE
TuttigliapparecchiFBTsonocostruitinelrispettodellepiøsevere

normativeinternazionalidisicurezzaedinottemperanzaairequisiti
dellaComunitàEuropea.Peruncorrettoedefficaceusodell’apparecchio
èimportanteprendereconoscenzadituttelecaratteristicheleggendo
attentamentelepresentiistruzioniedinparticolarelenotedisicurezza.
Duranteilfunzionamentodell’apparecchioènecessarioassicurare
un’adeguataventilazione.Evitarediracchiuderel’apparecchioinun
mobileprivodiaerazioneodiostruirelefessurediventilazioneedin
particolarelapresad’ariaposterioredellaventoladiraffreddamento.
Evitareinoltreditenerel’apparecchioinprossimitàdisorgentidicalore.
Questoapparecchioèpredispostoperilmontaggioinmobilerackstandard
19”.
Écomunqueconsigliabileinterporreunpannellodiaerazionetraun
apparecchioel’altro(vedifig.2.1.1).

.

2.1INSTALLATION
AllFBTequipmentismanufacturedinaccordancewiththemost

stringentinternationalsafetystandardsandincompliancewithEuropean
Communityrequisites.Inordertousetheequipmentcorrectlyand
effectively,itisimportanttobeawareofallitscharacteristicsbyreading
theseinstructionsandinparticularthesafetynotescarefully.
Whiletheequipmentisworking,itisnecessarytoprovideadequate
ventilation.Donotclosethisequipmentinsideanunventilatedcabinet
anddonotobstructtheairvents,inparticularnottheairintakeonthe
rearforthecoolingfan.
Donotkeeptheequipmentinthevicinityofsourcesofheat.
Thisequipmentcanbeequippedformountinginastandard19”.

.
Itisrecommendedthatyouplaceaventilationpanelbetweenone
pieceofequipmentandthenext(seeFigure2.1.1).

Fig.2.1.1

2.2ALIMENTAZIONE
Questoapparecchioèpredispostoperilfunzionamentocontensionedi

retea230V–10%50/60Hz.¨possibileutilizzarel’apparecchioanche
conunatensionediretedi115V–10%50/60Hz;atalscopoè
necessarioportareilselettore[7 ]inposizione“115V”.
Gliamplificatoridella SerieMPA possono ancheesserealimentaticon
unasorgenteesternadicorrentecontinuacontensionedi24Vche
deveessereapplicata,rispettandolepolarità,airelativiterminalidella
morsettiera[19].Inaccordoconlenormativedisicurezza,l’interruttore
diaccensione[4]agiscesolosullatensionedirete.
Indotazioneall’apparecchioèfornitouncavodialimentazioneconfilo
diterra;ilterminalediterradellaspinadiretenondeveessererimosso
inalcuncaso.
Collegarelaspinadirete[21]dell’apparecchioallareteelettrica
utilizzandol’appositocavofornitoindotazione;assicurarsichelapresa
dicorrentesiadotatadicollegamentoditerraanormadilegge.
L’apparecchioèprotettodaduefusibili(vedipar.4.4).

2.3NOTEDISICUREZZA
Ogniinterventoall’internodell’apparecchio,qualelaselezionedialcuni

modid’usoolasostituzionedifusibili,deveessereeffettuatosoloda
personalespecializzato:larimozionedelcoperchiorendeaccessibili
particonrischiodiscosseelettriche.
Primadirimuovereilcoperchioaccertarsisemprecheilcavodiretesia
staccato.
Nelcasodiaccidentalecadutadiliquidisull’apparecchio,staccare
immediatamentelaspinadireteedinterpellareilcentrodiassistenza
FBTpiùvicino.
Laconnessioneditelaio[20 ]consentedicollegarealtreapparecchiature
perlasolafunzionedischermaturadeisegnaliabassolivello: questa
presanondeveessereutilizzataperilcollegamentodisicurezzadeltelaio
allaterra.

2.2POWERSUPPLY
Thisequipmentisdesignedforusewithamainsvoltageof230V–10%

50/60Hz.Itisalsopossibletousetheequipmentwithamainsvoltage
of115V–10%50/60Hz,howeverinthiscaseitisnecessaryto
positiontheselectorswitch[7 ]on“115V”.
Theamplifiersofthe MPA Series canalsobepoweredbymeansofan
externalDCpowersupplywithavoltageof24V,whichhastobeapplied
totheappropriateterminalsontheterminalstrip[ 19 ]payingattention
tothecorrectpolarity.Asrequiredundersafetyregulations,the
ON/OFFswitch[4]onlycontrolsthemainsvoltage.
Theequipmentissuppliedwithitsownpower-supplycable,whichis
equippedwithanearthingwire.Theearthterminalofthemainsplug
shouldneverberemovedunderanycircumstances.
Connectthemainsplug[21]oftheequipmenttothepowermainsusing
thecableincludedinthesupply.Makesurethatthepoweroutletis
equippedwithaconnectiontoearthinaccordancewiththelaw.
Theequipmentisprotectedbytwofuses(seepoint4.4).

2.3SAFETYNOTES
Anyactivitiesinsidetheapparatus,suchasselectingsomeofthe

operatingmodes,theinstallationofaccessoriesorthereplacement
offuses,mustbecarriedoutbyspecializedpersonnelonly:whenthe
coverisremoved,partsliabletocauseelectricshocksareexposed.
Beforeremovingthecover,alwaysmakesurethatthepowercord
hasbeendisconnected.
Intheeventthatliquidisaccidentallyspiltontotheapparatus,
disconnectthemainsplugimmediatelyandcontactthenearestFBT
ServiceCentre.
Thechassisconnection[20]maybeusedtoconnectotherequipment
onlyforthepurposeofshieldingthelowsignals: thissocketmaynot
beusedtoconnectthechassistoearthforsafetypurposes.

5

CONNECTIONSCONNESSIONI

3.1CRITERIGENERALI
Peruncorrettofunzionamentodell’apparecchioèopportunoosservare

alcunicriteridimassimanell’esecuzionedeicollegamenti:

•evitareilposizionamentodicaviedimicrofonisulmobile
dell’apparecchio.

•evitaredistenderelelineedisegnaleparalleleaquelledirete;
osservareunadistanzaminimadi30/40cm.

•posizionarelelineediingressoelelineediuscitadistantitraloro.

•posizionareimicrofonialdifuoridell’angolodiradiazionedeidiffusori
sonoriperevitareilfenomenodireazioneacustica(effettoLarsen).

3.2INGRESSO/USCITADILINEA

Sulpannelloposterioredell’apparecchioèdisponibilel’ingressodilinea
INPUT [15]dell’unitàdipotenza:perilcollegamentosonodisponibili,a
secondadelleesigenze,unapresaXLRfemminaoppureunapresaper
spinottojackda1/4”.La spinaXLRmaschioelapresa perspinottojack
da1/4” OUTPUT [16 ]riportanolo stessosegnalepresenteallapresa
INPUT ,perunfacilecollegamentoincascatatrapiøunitàdipotenza.
Lostadiod’ingressoèditipo bilanciato, percuièpossibileeffettuare
collegamentisiaditipobilanciatochesbilanciato.
Lafigura3.2.1riportaleconnessioni,vistedall’esterno.

COLLEGAMENTOBILANCIATO-BALANCEDCONNECTION

1 =schermo/shield
2 =segnale(latocaldo)/signal(hotside)
3 =segnale(latofreddo)/signal(coldside)

3.1GENERALFEATURES
Forproperunitoperation,usethefollowinginstructionswhenmaking

theconnections:

•Donotplacecablesormicrophonesontheunitcabinet;

•Donotlaysignallinesparalleltopowerlines;ensureaminimum
distanceof30/40cmbetweenthem;

•Keepinputlinesandtheoutputlinesfarapart;

•Keepthemicrophonesoutsidetheoperatingspanofthespeakersto
avoidacousticfeedback(Larseneffect).

3.2LINEINPUT/OUTPUT

Theline INPUT[15]forthepowerunitissituatedontherearpanelof
theequipment.Dependingonrequirements,twosocketsareavailable:
afemaleXLRsocketandasocketfora1/4”jack.ThemaleXLRplugand
thesocketforthe1/4” OUTPUT jack[16]relaythesamesignalavailable
onthe INPUT socket,tomakeiteasiertoconnectseveralpowerunits
incascadeformation.
Theinputstageisofthebalancedtype,anditisthereforepossibleto
makebothbalancedandunbalancedconnections.
Figure3.2.1showstheconnections,seenfromoutside.

1 =segnale(latocaldo)/signal(hotside)
2 =segnale(latofreddo)/signal(coldside)
3 =schermo/shield

COLLEGAMENTOSBILANCIATO-UNBALANCEDCONNECTION

1 =schermoemassa/shieldand GND
2 =schermoemassa/shieldand GND

3 =segnale/signal

Fig.3.2.1

3.3INGRESSOTELEFONICO
L’apparecchioèpredispostoperilcollegamentoadunsistematelefonico

tramitelamorsettiera“TEL”[10].Taleingressoèbilanciatoa
trasformatore,possiedeunpropriocontrollodilivello-“ LEV.”[11 ]-edè
dotatodicircuitoVOXperladiffusionedeimessaggiconprioritàpiø
elevatarispettoaqualsiasialtroingresso.
L’ingressotelefonicoconsenteinoltreilcollegamentodell’apparecchioalle
basipreamplificateFBT .Perquestoènecessariorimuovere
lospinottopentapolareDINdalcavodellabaseeconifilirealizzarei
collegamentiillustratiinfig.3.3.1.Taleconfigurazioneconsenteanche
l’inviodiunsegnaledipreavviso(vedipar.3.5).
IMPORTANTE :perquestotipodicollegamentoè INDISPENSABILE
chiuderetramiteunponticelloicontatti[G]e[COM]dellamorsettiera
“TEL”[10].

.SOP

1 OMREHCS DLEIHS

OVAC

ELBAC

AREITTESROM

PIRTSLANIMRET

ELANIMRET

LANIMRET

[G]

1 =segnale/signal
2 =schermoemassa/shieldand GND

3.3TELEPHONEINPUT

Theequipmenthasprovisionsforconnectionofatelephonesystemby
meansofthe“TEL”terminalstrip[10].Thisinputisbalancedbya
transformer,hasitsownlevelcontrol-“ LEV.”[11 ]-andisequippedwith
aVOXcircuitforbroadcastingmessageswithahigherprioritylevelthan
anyotherinput.
Thetelephoneinputalsoenablestheequipmenttobeconnectedtothe
FBT preamplifiedbases.Todothis,itisnecessarytoremove
thefive-poleDINplugfromthecableonthebaseandusethewiresto
maketheconnectionsillustratedinFigure3.3.1.Thisconfigurationalso
enablesawarningsignaltobesent(seepoint3.5).
IMPORTANT :Forthistypeofconnectionitis ESSENTIALtoclosethe
contacts[G ]and[COM]ofthe“ TEL”terminalstrip[10 ]withajumper.

2 OREN KCALB [ MOC ]

3 OCNAIB ETIHW [ TOH ]
4 OSSOR DER
5 EDREV NEERG [P]

"LET"

[+]

"YTIROIRP"

Fig.3.3.1

6

CONNECTIONSCONNESSIONI

3.4USCITA‘MUSICONHOLD’(MOH)
Aquestimorsetti[9 ]e’disponibileilsegnalepresenteall’ingresso INPUT

[15];talesegnalenone’soggettoall’azionediprecedenzamicrofonicao
telefonica.Inparticolare,l’uscitabilanciataatrasformatore(morsetti
1-2-3 difig.3.4.1)puo’essereutilizzataperilpilotaggiodiunulteriore
amplificatore,diuncentralinotelefonicoodaltro;l’uscitadipotenza
(morsetti3-4 difig.3.4.1)e’ingradodipilotaredirettamenteunpiccolo
altoparlantemonitorda8Ω conpotenzamassimadi1W.
Épossibileregolareillivellodiuscitaagendosulcontrollo“LEV.”[8 ].

1:600Ω (linea-latocaldo)

(line-warmside)

2:600Ω (linea-latofreddo)

(line-coldside)

3:massaeschermo

GNDandshield

4:1W/8Ω uscitaaltoparlanti

loudspeakersoutput

Fig.3.4.1

3.5PRECEDENZAESEGNALEDIPREAVVISO
Chiudendoicontattidellamorsettiera“PRIORITY”[ 13 ]viene

ammutolitoilsegnalepresenteallpresa INPUT [15];lachiusuradel
contattogeneraunsegnaledipreavvisoaduetoni(CHIME)seilselettore
“CHIME”[12 ]sitrovainposizione ON.
Épossibilemodificareillivellodelsegnaledipreavvisoagendosultrimmer
semifisso VR301 postosulcircuitoPriority(v edipar.2.3).

3.4‘MUSICONHOLD’OUTPUT(MOH)
Thesignalavailableon INPUT[15 ]isalsoavailableontheseterminals

[9].Thissignalisnotaffectedbytheuseoftelephoneprecedence.
Inparticular,thebalancedtransformeroutput(strips 1-2-3 ,Fig.3.4.1)
canbeusedtodriveanadditionalamplifier,atelephoneexchangeor
otherequipment.Thepoweroutput(terminals 3-4 inFigure3.4.1)is
capableofdrivingdirectlyasmall8 Ω monitoringloudspeakerwitha
maximumoutputof1W.
Itispossibletoadjusttheoutputlevelbymeansofthe “LEV.”
control[8 ].

5:TEL(massaschermo)

(GNDandshield)

6:TEL(ingresso-latofreddo)

(input-coldside)

7:TEL(ingresso-latocaldo)

(input-warmside)

3.5PRIORITYANDWARNINGSIGNAL
Ifthecontactsofthe“PRIORITY ”terminalstrip[13]areclosed,the

signalonthe INPUT socket[15 ]ismuted.Closingthecontactcausesa
two-tonewarningsignal(CHIME)tobegenerated.The“ CHIME ”switch
[12]isinthe ON position.
Itispossibletochangethelevelofthewarningsignalbymeansofthe
semi-fixedtrimmer VR301 onthePrioritycircuit(seepoint2.3).

3.6USCITEDIPOTENZA
Leuscitedipotenzaperidiffusorisonodisponibilisullamorsettiera[18].

¨possibilerealizzareunimpiantodidiffusionesonorautilizzandosia
diffusoriabassaimpedenza,siadiffusoridotatiditraslatoredilinea.
Inentrambiicasiilcaricocomplessivonondeveesseretaleda
sovraccaricarel’amplificatore:nonapplicarecioèdiffusoriogruppidi
diffusoriconimpedenzapiøbassadiquellanominaledellapresaalla
qualesonocollegati.Siraccomandainoltrediporreparticolareattenzione
alcalcolodelleimpedenzenelcasosidebbanorealizzareimpiantidi
diffusionemisti(abassaimpedenzaeatensionecostante).
Intabella3.6.1sonoriportatiivalorinominaliditensioneedimpedenza
perlediverseuscite.

Uscita

8 Ω

50V
70V

100V

3.6.1 Sistemiabassaimpedenza
Inapplicazionicherichiedonol’usodipochialtoparlanti,lalineadi
collegamentopuòessereconnessatrailterminalecomune“0”elapresa
“8 ΩΩΩΩΩ”dellamorsettiera[18].
Ilcollegamentodeglialtoparlanti,ditiposerieoparalleloomisto,deve
fornireun’impedenzacalcolatapariosuperioread8.Ω
Infigura3.6.1Øriportatounesempiodicollegamento.

AW5240

43,8V

10,4 Ω
20,4 Ω
41,7 Ω

Tabella3.6.1

AW5120

31V

20,8 Ω
40,8 Ω
83,3 Ω

3.6POWEROUTPUTS
Thepoweroutputsfortheloudspeakersareavailableontheterminal

strip[18 ].Itispossibletosetupasound-broadcastingsystem
usingeitherlow-impedanceloudspeakersorloudspeakersequippedwith
alinetransformer.Inbothcasestheoverallloadmustnotbesuchasto
overloadtheamplifier.Thismeansthatyoumustnotapplyloudspeakers
orgroupsofloudspeakerswithanimpedancelowerthantherated
impedanceofthesockettowhichtheyareconnected.Itisalso
necessarytopayparticularattentiontocalculatingtheimpedancevalues
ifmixedbroadcastingsystems(lowimpedanceandconstantvoltage)
aretobesetup.
Table3.6.1showsvoltageandimpedanceratedvaluesforthevarious
outputs.

Output

8 Ω

50V
70V

100V

3.6.1 Low-impedancesystems
Inapplicationsthatrequiretheuseonlyofafewloudspeakers,the
connectinglinemaybeconnectedbetweenthecommonterminal“0 ”and
the“8ΩΩΩΩΩ”socketoftheterminalstrip[ 18].
Theloudspeakerconnection,whetheroftheserialorparalleltypeor
mixed,shouldprovideanimpedancecalculatedtobeequaltoorhigher
than8Ω.AnexampleofaconnectionisshowninFigure3.6.1.

AW5240

43,8V

10,4 Ω
20,4 Ω
41,7 Ω

Table3.6.1

AW5120

31V

20,8 Ω
40,8 Ω
83,3 Ω

7

CONNECTIONSCONNESSIONI

•Calcolodell’impedenzaneicollegamentiinserie
Nelcasodidiffusoricollegatiinserietraloro,l’impedenzatotaleèla
sommadellesingoleimpedenze:

impedenzatotale = Z1 + Z2 + Z3+ ....

•Calcolodel l’impedenzaneicollegamentiinparallelo
Nelcasodidiffusoricollegatiinparallelotraloro,l’impedenzatotalepuò
esseredeterminatamediantelaseguenteformula:

impedenzatotale =

1

Z1

+

1

1

++......

Z2

1

Z3

•Calculatingtheimpedancevalueinseriesconnections
Inthecaseofloudspeakersconnectedtooneanotherinseries,thetotal
impedanceisthesumofthesingleimpedancevalues:

Totalimpedance = Z1 + Z2 + Z3+ ....

•Calculatingtheimpedancevalueinparallelconnection
Intheeventofloudspeakersconnectedinparalleltooneanotherthe
totalimpedancecanbecalculatedbymeansofthefollowingformula:

Totalimpedance =

1

Z1

+

1

1

++......

Z2

1

Z3

16ΩΩΩΩΩ16ΩΩΩΩΩ

Fig.3.6.1

3.6.2 Sistemiatensionecostante
Nelcasodiimpianticonungrannumerodidiffusorie/ocondistanzetra
amplificatoriedaltoparlantimoltoelevateèpreferibileutilizzareunsistema
didistribuzioneatensionecostante(definitoancheadaltaimpedenza).
Inquestotipodiimpianto,idiffusori,provvistiditrasformatoridi
adattamentodiimpedenza,sonotutticollegatiinderivazioneallalinea
(vedies.diFig.3.6.2);questoparticolarerendedifacilerealizzazione
l’impiantoe,nelcasoincuiunaltoparlantedovesseperqualchemotivo
scollegarsidallalinea,ilrestodell’impiantoproseguirebbenelsuoregolare
funzionamento.Letensionicostantidisponibiliinuscitadall’amplificatore
sono 50 , 70 e 100V.

•Calcolodelnumerodidiffusori(tramitelepotenze)
Sisuppongadiaveredefinitosial’amplificatore(cioèlasuapotenzadi
uscita)cheiltipodidiffusoreconrelativapotenzaassorbita.
Inquestocasoilmassimonumerodidiffusoricollegabilesullalineaè
determinatodallaseguenteformula:

numerodiffusori =

potenzaamplificatore

potenzadiffusore

20W20W

Fig.3.6.2

3.6.2 Constantvoltagesystems
Whenalargenumberofspeakersisusedand/orthespeakersare
placedfarfromtheamplifiers,constantvoltagedistributionsystem
shouldbeused(alsoknownashigh-impedancesystems).
Inthistypeofsystem,thespeakersarefittedwithimpedance
adaptationtransformersandallofthemhaveshuntlineconnections
(seeexampleofFig.3.6.2).Thissimplifiesthelayoutofthesystemand
if,foranyreason,aloudspeakerisdisconnectedfromtheline,therest
ofthesystemwillcontinuetoworkproperly.Theconstantvoltages
outputfromtheamplifierare 50 , 70 and 100V.

•Determiningthenumberofspeakers(throughpowervalues)
Ifboththeamplifier(i.e.itsoutputpower)andthetypeofspeaker
withitspowerconsumptionhavebeenestablished,themaximumnumber
ofspeakerswhichmaybeconnectedtothelinemaybedeterminedas
follows:

numberofspeakers =

amplifierpower

speakerpower