Korg 73key Electronic Keyboard User Manual


 
Playing and editing Programs
38
Using Filters
Thefiltersallowyoutodiminishoremphasize
specifiedfrequencyareasofthesound.
Thetoneofthesoundwilldependsignificantlyon
thefiltersettings.
Thebasicfiltersettings,includingtherouting,type,
cutofffrequency,andresonance,aresetontheP3–1:
Filterpage.
Filter Routing
Eachoscillatorhastwofilters,FilterAandFilterB.The
FilterRoutingparametercontrolswhetheroneorboth
ofthefiltersareused,andifbothareused,itcontrols
howtheyareconnectedtoeachother.
TheSingleroutingusesonlyFilterAasasingle2pole,
12dB/octavefilter(6dBforBandPassandBandReject).
TheSerialroutingusesbothFilterAandFilterB.The
oscillatorfirstgo
esthroughFilterA,andthenthe
outputofFilterAisprocessedthroughFilterB.
ParallelalsousesbothFilterAandFilterB.The
oscillatorfeedsbothfiltersdirectly(andallow
independentsettingsforeach),andtheoutputsofthe
twof
iltersarethensummedtogether.
The24dB(4Pole)routingmergesbothfilterstocreatea
single4pole,24dB/octavefilter(12dBforBandPass
andBandReject).IncomparisontoSingle,thisoption
producesasharperrolloffoffrequenciesbeyondthe
cutofffrequency,aswellasaslightlymorede
licate
resonance.Manyclassicanalogsynthsusedthistype
offilter.
SerialandParallelRouting
Filter Types
Thisselectsthepartsofthesoundthatwillbeaffected
bythefilter,asdescribedbelow.WiththeSerialand
Parallelroutings,youcanindependentlysetthetypes
forFilterAandFilterB.
Thefilterswillproduceverydifferentresults
dependingontheselectedfiltertype.
LowPass:Thiscutsoutthepartsofthesoundthatare
higherthanthecutofffrequency.LowPassisthemost
commontypeoffilter,andisusedtomakebright
timbressounddarker.
HighPass:Thiscutsoutthepartsofthesoundthatare
lowerthanthecutofffrequency.Youcanusethisto
maketimbressoundthinnerormorebuzzy.
BandPass:Thiscutsoutallpartsofthesou
nd,both
highsandlows,exceptfortheregionaroundthecutoff
frequency.Sincethisfiltercutsoutbothhighandlow
frequencies,itseffectcanchangedramatically
dependingonthecutoffsettingandtheoscillator’s
multisample.
Withlo
wresonancesettings,youcanusetheBand
Passfiltertocreatetelephoneorvintagephonograph
sounds.Withhigherresonancesettings,itcancreate
buzzyornasaltimbres.
BandReject:Thisfiltertype–alsocalledanotchfilter–
cutsonlythepartsofthesounddirectlyaroundthe
cutofffrequency.Trymodulatingthecutoffwithan
LFOtocreatephaserlikeeffects.
FilterTypesandCutoffFrequency
Filter A (Low Pass)Oscillator
Oscillator
Filter B (High Pass)
Filter A (Low Pass)
Filter B (High Pass)
Low Pass
High Pass
Band Pass
Band Reject
Cutoff Frequency