So I implemented the module below. I used a low pass filter and and high pass filter instead of testing the frequencies as per my initial question. Frequencies below the low pass (typically set at 400Hz) have a +2 oct dominance and a lesser, if any, + 1oct. Frequencies above the high pass (typically set at 400Hz as well) have a + 1oct dominance and a lesser +2 oct. I also try to add a low frequency chorus on the high pass.
So it sort of works, but the biggest problem is that there is some sort of "flubber" in the sound, can't really describe it, but it's obvious when you use the preset. I wonder if it has to do with applying EQ in combination to pitch shifting, although on whole octaves.
It makes it kind of hard to use, unless the gain is much lower. I don't think it's due to the chorus being applied to only the shifted freqs above the high pass, as it did the same thing without the chorus.
Dunno, if anyone has any ideas, I'm sharing the module below in case we can make it work better.
PS: I researched what other software does, via users groups. I found a few "naive" presets on the Guitar Rig site where all they do is shift the entire signal by +1 oct and nothing else. It sounds disastrous, yet the users seem to think it sounds good. I guess they never heard an Eventide…
HEADM adc 2 2 stereomixer1-left stereomixer1-right "12 String v2" Empty 1 "Main Menu-obj" ;=200,0,100,0
FILTER "High Pass R" adc-in2 "HP Freq-out" 0 2 ;=300,75,100,0
KNOB "HP Freq" "HP Freq: %5.0fHz" "HP Freq" 25 20000 5 400 ;=150,225,100,0
FILTER "High Pass L" adc-in1 "HP Freq-out" 1 2 ;=450,25,100,0
MENUPAGE "Main Menu" "12 String" "12 Str" 9 "Dry Gain-obj" "HP Freq-obj" "HP Gain-obj" "LP Freq-obj" "LP Gain-obj" "L Shift Freq-obj" "L feedback-obj" "L Shift Freq1-obj" "L feedback1-obj" ;=300,425,100,0
STEREOMIXER stereomixer1 6 adc-in1 adc-in2 "L shiftMix-out" "L shiftMix1-out" "pitchshift L1-out" "pitchshift R1-out" "Dry Gain-out" "Dry Gain-out" "HP Gain-out" "HP Gain-out" "LP Gain-out" "LP Gain-out" -1 1 -1 1 -1 1 ;=600,25,100,0
KNOB "Dry Gain" "Dry Gain: %3.0fdb" "Dry Gain" -100 0 1 -3 ;=450,175,100,0
KNOB "HP Gain" "HPass Gain: %3.0fdb" "HP Gain" -100 0 1 -6 ;=450,300,100,0
PITCHSHIFT "pitchshift L" "High Pass L-out" 21 -60 10 adc-null 1200 0 0 ;=825,150,100,0
PITCHSHIFT "pitchshift R" "High Pass R-out" 21 -60 10 adc-null 1200 0 0 ;=1025,25,100,0
KNOB "LP Freq" "LPass Freq: %5.0fHz" "LP Freq" 25 20000 5 400 ;=400,650,100,0
FILTER "Low Pass L" adc-in1 "LP Freq-out" 1 0 ;=600,650,100,0
FILTER "Low Pass R" adc-in2 "LP Freq-out" 0 0 ;=775,650,100,0
PITCHSHIFT "pitchshift L1" "Low Pass L-out" 21 -60 10 adc-null 3600 0 0 ;=975,425,100,0
PITCHSHIFT "pitchshift R1" "Low Pass R-out" 21 -60 10 adc-null 3600 0 0 ;=1150,425,100,0
KNOB "LP Gain" "LPass Gain: %3.0fdb" "LP Gain" -100 0 1 -6 ;=100,675,100,0
FREQSHIFT "L freqshift" "L shiftMix-out" "L Shift Freq-out" ;=1625,700,100,0
MIX "L shiftMix" "pitchshift L-out" "L freqshift-out" 1 "L feedback-out" ;=1450,700,100,0
KNOB "L Shift Freq" "HL Shift Freq: %5.2f Hz" knob -10 10 0.01 1.4 ;=1175,725,100,0
PERCENTKNOB "L feedback" "HL fback: %4.0f %%" percent -100 100 1 40 ;=1300,725,100,0
PERCENTKNOB "L feedback1" "HR fback: %4.0f %%" percent -100 100 1 40 ;=1325,875,100,0
KNOB "L Shift Freq1" "HR Shift Freq: %5.2f Hz" knob -10 10 0.01 1.4 ;=1175,875,100,0
MIX "L shiftMix1" "pitchshift R-out" "L freqshift1-out" 1 "L feedback1-out" ;=1475,850,100,0
FREQSHIFT "L freqshift1" "L shiftMix1-out" "L Shift Freq1-out" ;=1700,900,100,0
