delayfiltersinloop.csd Written by Iain McCurdy, 2006 THE deltap3 OPCODE IS PLACED IN A SEPARATE, ALWAYS ON, INSTRUMENT FROM THE SOURCE SOUND PRODUCING INSTRUMENT. THE IS A COMMONLY USED TECHNIQUE WITH TIME SMEARING OPCODES AND EFFECTS LIKE REVERBS AND DELAYS. ksmps MAY NEED TO BE LOW (AND kr THEREFORE HIGH) WHEN WORKING WITH SHORT DELAY TIMES DEFINED INITIALLY AT KRATE -iadc -odac -dm0 sr = 44100 ;SAMPLE RATE ksmps = 4 ;NUMBER OF AUDIO SAMPLES IN EACH CONTROL CYCLE (MAY NEED TO BE LOW WHEN WORKING WITH SHORT DELAY TIMES DEFINED INITIALLY AT KRATE) nchnls = 2 ;NUMBER OF CHANNELS (2=STEREO) 0dbfs = 1 ;MAXIMUM AMPLITUDE ;FLTK INTERFACE CODE;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; FLcolor 255, 255, 255, 0, 0, 0 ; LABEL | WIDTH | HEIGHT | X | Y FLpanel "delay with filters in feedback loop", 500, 400, 0, 0 ; ON | OFF | TYPE | WIDTH | HEIGHT | X | Y | OPCODE | INS | STARTTIM | DUR gkOnOff,ihOnOff FLbutton "Input On/Off", 1, 0, 22, 180, 25, 5, 5, 0, 1, 0, -1 FLsetColor2 255, 255, 50, ihOnOff ;SET SECONDARY COLOUR TO YELLOW ;GENERAL_TEXT_SETTINGS SIZE | FONT | ALIGN | RED | GREEN | BLUE FLlabel 13, 1, 3, 255, 255, 255 ;LABELS MADE INVISIBLE (I.E. SAME COLOR AS PANEL) ;BUTTON BANKS TYPE | NUMX | NUMY | WIDTH | HEIGHT | X | Y | OPCODE | INS | STARTTIM | DUR gkinput, ihinput FLbutBank 14, 1, 2, 18, 40, 250, 0, -1 ;GENERAL_TEXT_SETTINGS SIZE | FONT | ALIGN | RED | GREEN | BLUE FLlabel 13, 1, 3, 0, 0, 0 ;LABELS MADE VISIBLE AGAIN ;TEXT BOXES TYPE | FONT | SIZE | WIDTH | HEIGHT | X | Y ih FLbox "Input", 1, 5, 14, 50, 16, 200, 0 ih FLbox "Drum Loop", 1, 5, 14, 75, 16, 270, 0 ih FLbox "Live ", 1, 5, 14, 75, 16, 270, 20 ;VALUE_DISPLAY_BOXES WIDTH | HEIGHT | X | Y iddlt FLvalue " ", 80, 20, 5, 75 idmix FLvalue " ", 80, 20, 5, 125 idfeedbackamt FLvalue " ", 80, 20, 5, 175 idamp FLvalue " ", 80, 20, 5, 225 idporttime FLvalue " ", 80, 20, 5, 275 idHPFcf FLvalue " ", 80, 20, 5, 325 idLPFcf FLvalue " ", 80, 20, 5, 375 ;SLIDERS MIN | MAX | EXP | TYPE | DISP | WIDTH | HEIGHT | X | Y gkdlt,ihdlt FLslider "Delay Time (sec)", .001, 5, 0, 23, iddlt, 490, 25, 5, 50 gkmix,ihmix FLslider "Dry/Wet Mix", 0, 1, 0, 23, idmix, 490, 25, 5, 100 gkfeedamt,ihfeedamt FLslider "Feedback Amount", 0, 2, 0, 23, idfeedbackamt, 490, 25, 5, 150 gkamp,ihamp FLslider "Output Amplitude Rescaling", 0, 1, 0, 23, idamp, 490, 25, 5, 200 gkporttime,ihporttime FLslider "Portamento Time", 0, 2, 0, 23, idporttime, 490, 25, 5, 250 gkHPFcf,ihHPFcf FLslider "High Pass Filter Cutoff", 20, 20000, -1, 23, idHPFcf, 490, 25, 5, 300 gkLPFcf,ihLPFcf FLslider "Low Pass Filter Cutoff", 20, 20000, -1, 23, idLPFcf, 490, 25, 5, 350 gkingain,ihingain FLslider "Live Input Gain", 0, 1, 0, 23, -1, 140, 20, 350, 5 ;SET_INITIAL_VALUES VALUE | HANDLE FLsetVal_i .31, ihdlt FLsetVal_i .5, ihmix FLsetVal_i 1.08, ihfeedamt FLsetVal_i .7, ihamp FLsetVal_i 0.3, ihporttime FLsetVal_i 2000, ihHPFcf FLsetVal_i 7000, ihLPFcf FLpanel_end ;END OF PANEL CONTENTS ;INSTRUCTIONS AND INFO PANEL FLpanel " ", 500, 320, 512, 0 ;TEXT BOXES TYPE | FONT | SIZE | WIDTH | HEIGHT | X | Y ih FLbox " delayr delayw deltap3 - filters in loop ", 1, 5, 14, 490, 15, 5, 0 ih FLbox "-------------------------------------------------------------", 1, 5, 14, 490, 15, 5, 20 ih FLbox "This example adds a low pass and a high pass filter within ", 1, 5, 14, 490, 15, 5, 40 ih FLbox "the feedback loop. The result of doing this is that each time", 1, 5, 14, 490, 15, 5, 60 ih FLbox "the signal loops around the system it will be more sharply ", 1, 5, 14, 490, 15, 5, 80 ih FLbox "filtered. (This is equivalent to iterative filtering.) ", 1, 5, 14, 490, 15, 5, 100 ih FLbox "Feedback values greater than 100% (I.E. value=1) are now ", 1, 5, 14, 490, 15, 5, 120 ih FLbox "possible as the signal is likely to be attenuated by the ", 1, 5, 14, 490, 15, 5, 140 ih FLbox "filters anyway. The signal is clipped at maximum amplitude ", 1, 5, 14, 490, 15, 5, 160 ih FLbox "using the 'clip' opcode anyway. This type of delay effect ", 1, 5, 14, 490, 15, 5, 180 ih FLbox "simulates the signal degradation that is evident in analog ", 1, 5, 14, 490, 15, 5, 200 ih FLbox "tape loop delay systems when using signal feedback. These ", 1, 5, 14, 490, 15, 5, 220 ih FLbox "were frequently used in dub reggae. ", 1, 5, 14, 490, 15, 5, 240 ih FLbox "In this example the user can choose between a drum loop sound", 1, 5, 14, 490, 15, 5, 260 ih FLbox "file as input or the computer's live input. A gain control is", 1, 5, 14, 490, 15, 5, 280 ih FLbox "is provided to control the gain of the live input. ", 1, 5, 14, 490, 15, 5, 300 FLpanel_end FLrun ;RUN THE FLTK WIDGET THREAD ;END OF FLTK INTERFACE CODE;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; instr 1 ;PLAYS FILE if gkOnOff=0 then ;SENSE FLTK ON/OFF SWITCH turnoff ;TURN THIS INSTRUMENT OFF endif ;END OF CONDITIONAL BRANCHING if gkinput==0 then ;IF INPUT '808loop.wav' IS SELECTED... gasigL, gasigR diskin2 "808loop.wav", 1, 0, 1 ;GENERATE 2 AUDIO SIGNALS FROM A STEREO SOUND FILE (NOTE THE USE OF GLOBAL VARIABLES) else ;OTHERWISE asigL, asigR ins ;TAKE INPUT FROM COMPUTER'S AUDIO INPUT gasigL = asigL * gkingain ;SCALE USING 'Input Gain' SLIDER gasigR = asigR * gkingain ;SCALE USING 'Input Gain' SLIDER endif ;END OF CONDITIONAL BRANCHING endin instr 2 ;DELAY INSTRUMENT kporttime linseg 0, .001, 1, 1, 1 ;USE OF AN ENVELOPE VALUE THAT QUICKLY RAMPS UP FROM ZERO TO 1. THIS PREVENTS VARIABLES GLIDING TO THEIR REQUIRED VALUES EACH TIME THE INSTRUMENT IS STARTED. kporttime = kporttime * gkporttime ;SCALE PORTAMENTO FUNCTION WITH FLTK SLIDER VALUE kdlt portk gkdlt, kporttime ;PORTAMENTO IS APPLIED TO THE VARIABLE 'gkdlt'. A NEW VARIABLE 'kdlt' IS CREATED. adlt interp kdlt ;A NEW A-RATE VARIABLE 'adlt' IS CREATED BY INTERPOLATING THE K-RATE VARIABLE 'kdlt' ;;;LEFT CHANNEL DELAY;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; abufferL delayr 5 ;CREATE A DELAY BUFFER OF 5 SECONDS DURATION (EQUIVALENT TO THE MAXIMUM DELAY TIME POSSIBLE USING THIS EXAMPLE) adelsigL deltap3 adlt ;TAP THE DELAY LINE AT gkdlt SECONDS adelsigL clip adelsigL, 0, 1 ;SIGNAL IS CLIPPED AT MAXIMUM AMPLITUDE USING BRAM DE JONG METHOD adelsigL atone adelsigL, gkHPFcf ;LEFT CHANNEL DELAY PASSED THROUGH A HIGH-PASS FILTER WITHIN THE DELAY LOOP adelsigL tone adelsigL, gkLPFcf ;LEFT CHANNEL DELAY PASSED THROUGH A LOW-PASS FILTER WITHIN THE DELAY LOOP delayw gasigL + (adelsigL * gkfeedamt) ;WRITE AUDIO SOURCE AND FEEDBACK SIGNAL INTO THE BEGINNING OF THE BUFFER ;;;RIGHT CHANNEL DELAY;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; abufferR delayr 5 ;CREATE A DELAY BUFFER OF 5 SECONDS DURATION (EQUIVALENT TO THE MAXIMUM DELAY TIME POSSIBLE USING THIS EXAMPLE) adelsigR deltap3 adlt ;TAP THE DELAY LINE AT gkdlt SECONDS adelsigR clip adelsigR, 0, 1 ;SIGNAL IS CLIPPED AT MAXIMUM AMPLITUDE USING BRAM DE JONG METHOD adelsigR atone adelsigR, gkHPFcf ;RIGHT CHANNEL DELAY PASSED THROUGH A HIGH-PASS FILTER WITHIN THE DELAY LOOP adelsigR tone adelsigR, gkLPFcf ;RIGHT CHANNEL DELAY PASSED THROUGH A LOW-PASS FILTER WITHIN THE DELAY LOOP delayw gasigR + (adelsigR * gkfeedamt) ;WRITE AUDIO SOURCE AND FEEDBACK SIGNAL INTO THE BEGINNING OF THE BUFFER aL ntrpol gasigL, adelsigL, gkmix aR ntrpol gasigR, adelsigR, gkmix outs aL * gkamp, aR * gkamp ;CREATE A MIX BETWEEN THE WET AND THE DRY SIGNALS AT THE OUTPUT clear gasigL, gasigR ;CLEAR THE GLOBAL AUDIO SEND VARIABLES endin ;INSTR | START | DURATION i 2 0 -1 ;INSTRUMENT 2 PLAYS A HELD NOTE f 0 3600 ;'DUMMY' SCORE EVENT KEEPS REALTIME PERFORMANCE GOING FOR 1 HOUR