Korg 61key, 73key, 88key Using Filters

Playing and editing Programs
38
Using Filters
Thefiltersallowyoutodiminishoremphasize
specifiedfrequencyareasofthesound.
Thetoneofthesoundwilldependsignificantlyon
thefiltersettings.
Thebasicfiltersettings,includingtherouting,type,
cutofffrequency,andresonance,aresetontheP3–1:
Filterpage.
Filter Routin g
Eachoscillatorhastwofilters,FilterAandFilterB.The
FilterRoutingparametercontrolswhetheroneorboth
ofthefiltersareused,andifbothareused,itcontrols
howtheyareconnectedtoeachother.
TheSingleroutingusesonlyFilterAasasingle2‐pole,
12dB/octavefilter(6dBforBandPassandBandReject).
TheSerialroutingusesbothFilterAandFilterB.The
oscillatorfirstgoesthroughFilterA,andthenthe
outputofFilterAisprocessedthroughFilterB.
ParallelalsousesbothFilterAandFilterB.The
oscillatorfeedsbothfiltersdirectly(andallow
independentsettingsforeach),andtheoutputsofthe
twofiltersarethensummedtogether.
The24dB(4Pole)routingmergesbothfilterstocreatea
single4‐pole,24dB/octavefilter(12dBforBandPass
andBandReject).IncomparisontoSingle,thisoption
producesasharperroll‐offoffrequenciesbeyondthe
cutofffrequency,aswellasaslightlymoredelicate
resonance.Manyclassicanalogsynthsusedthistype
offilter.
SerialandParallelRouting
Filter Types
Thisselectsthepartsofthesoundthatwillbeaffected
bythefilter,asdescribedbelow.WiththeSerialand
Parallelroutings,youcanindependentlysetthetypes
forFilterAandFilterB.
Thefilterswillproduceverydifferentresults
dependingontheselectedfiltertype.
LowPass:Thiscutsoutthepartsofthesoundthatare
higherthanthecutofffrequency.LowPassisthemost
commontypeoffilter,andisusedtomakebright
timbressounddarker.
HighPass:Thiscutsoutthepartsofthesoundthatare
lowerthanthecutofffrequency.Youcanusethisto
maketimbressoundthinnerormorebuzzy.
BandPass:Thiscutsoutallpartsofthesound,both
highsandlows,exceptfortheregionaroundthecutoff
frequency.Sincethisfiltercutsoutbothhighandlow
frequencies,itseffectcanchangedramatically
dependingonthecutoffsettingandtheoscillator’s
multisample.
Withlowresonancesettings,youcanusetheBand
Passfiltertocreatetelephoneorvintagephonograph
sounds.Withhigherresonancesettings,itcancreate
buzzyornasaltimbres.
BandReject:Thisfiltertype–alsocalledanotchfilter–
cutsonlythepartsofthesounddirectlyaroundthe
cutofffrequency.Trymodulatingthecutoffwithan
LFOtocreatephaser‐likeeffects.
FilterTypesandCutoffFrequency
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