I'm really into the idea of an Ableton-style FM synth for M4L that uses the same basic format with loads of extra features. I'm running into problems, though. First, with terms like 'harmonicity' and 'modulation index.' I've gotten the math to calculate harmonicity using the simple coarse/semitones/fine scheme, but mod index is still confusing me. In the Max tutorial the function is set to a range of 0-24. Can anyone explain this? I've tried scaling it with less than desirable results.

Next, how do the algorithms come into play? If it's a simple answer of 'lots of gate~ and selector~ objects' that's fine and I can toil over it for a while longer. Max's SimpleFM~ tutorial patch is a bit too simple for deducing the answer, so I'm just wondering if there's a simpler solution. Essentially I want to have 4 to 8 oscillators to incorporate into this thing.

I've been troubled with this for months, coming back to it over and over and not getting any further. Can anyone give me any pointers? Here's what I've got so far.

I'm really into the idea of an Ableton-style FM synth for M4L that uses the same basic format with loads of extra features.  I'm running into problems, though.  First, with terms like 'harmonicity' and 'modulation index.'  I've gotten the math to calculate harmonicity using the simple coarse/semitones/fine scheme, but mod index is still confusing me.  In the Max tutorial the function is set to a range of 0-24.  Can anyone explain this?  I've tried scaling it with less than desirable results.

Next, how do the algorithms come into play?  If it's a simple answer of 'lots of gate~ and selector~ objects' that's fine and I can toil over it for a while longer.  Max's SimpleFM~ tutorial patch is a bit too simple for deducing the answer, so I'm just wondering if there's a simpler solution.  Essentially I want to have 4 to 8 oscillators to incorporate into this thing.

I've been troubled with this for months, coming back to it over and over and not getting any further.  Can anyone give me any pointers?  Here's what I've got so far.


looking-to-design-an-fm-synth-like-operator

>Next, how do the algorithms come into play?

I have a basic FM operator abstraction. Then for each "algorithm", I have a separate patch with different arrangements of the operators and different routing. These patches are loaded dynamically into a poly~ (depending on which algorithm is used). The poly~ has a low signal vector size so that the algorithms can include a feedback loop with minimal delay.

#P hidden newex 407 164 72 196617 pattr interval;

#P hidden newex 409 43 54 196617 pattr amp;

#X prestore 21 0 2000. 0. 1. 0. 0. 0 146.788986 0.859375 0 366.972473 0.65625 0 1522.935669 0.609375 2 1798.165039 0.09375 0 2000. 0. 0;

#P hidden newex 409 12 54 196617 pattr mod;

#X prestore 24 0 2000. 0. 24. 55.045868 5.25 0 733.944946 18.75 0 1137.614624 5.25 0 1394.495361 7.125 2 1596.3302 1.5 0 1761.467773 3.75 0 2000. 0. 0;

#P hidden newex 352 -42 54 196617 pattr mod;

#P hidden newex 305 -60 51 196617 pattr dur;

#P hidden newex 6 -40 64 196617 pattr power;

#P hidden newex -59 -34 59 196617 pattr harm;

#P hidden newex -91 92 74 196617 pattr volume3;

#P hidden newex -94 67 74 196617 pattr volume2;

#P hidden newex -92 46 74 196617 pattr volume1;

#P hidden newex 194 -33 41 196617 * 127.;

#P hidden newex 122 -33 70 196617 snapshot~ 20;

#P hidden newex 122 -55 98 196617 receive~ phaseorrr;

#P hidden newex -584 13 70 196617 receive clear;

#P hidden newex 325 218 56 196617 send clear;

#P hidden message -510 57 28 196617 dump;

#P hidden message -513 80 31 196617 erase;

#P hidden message -592 67 59 196617 record $1;

It's in 4.6 and I don't know how they talk with each other, but that's a patch I made for using my keyboard as an 'instrument' and recording based on a networked phasor to keep time. It was while performing with Mobile Performance Group =) I apologize for the total chaos of the patch =,( First time opening it in 3 years =P.

You'll need to just make a sub-patch to replace the "SimpleFM.mxb" that is in the lower left of the unlocked patch. Just copy this inside it.

#P comment 123 141 92 1310730 modulator amplitude;

#P comment 109 116 92 1310730 modulating oscillator;

#P comment 75 190 74 1310730 carrier oscillator;

#P comment 164 25 77 1310730 Modulation index;

#P comment 85 25 77 1310730 Harmonicity ratio;

#P comment 5 25 74 1310730 Carrier frequency;

#P window setfont "Fixedwidth Serif" 10.;

It's in 4.6 and I don't know how they talk with each other, but that's a patch I made for using my keyboard as an 'instrument' and recording based on a networked phasor to keep time.  It was while performing with Mobile Performance Group =)  I apologize for the total chaos of the patch =,(  First time opening it in 3 years =P.  

You'll need to just make a sub-patch to replace the "SimpleFM.mxb" that is in the lower left of the unlocked patch.  Just copy this inside it.

_________Max 4.6 copy+paste_______
#P window setfont Times 10.;
#P window linecount 1;
#P comment 123 141 92 1310730 modulator amplitude;
#P comment 109 116 92 1310730 modulating oscillator;
#P comment 75 190 74 1310730 carrier oscillator;
#P comment 164 25 77 1310730 Modulation index;
#P comment 85 25 77 1310730 Harmonicity ratio;
#P comment 5 25 74 1310730 Carrier frequency;
#N comlet FM signal;
#P outlet 31 213 15 0;
#P window setfont "Fixedwidth Serif" 10.;
#P newex 113 87 38 1441802 *~ $2;
#P newex 31 164 43 1441802 +~;
#P newex 64 61 38 1441802 *~ $1;
#P newex 64 139 59 1441802 *~;
#P newex 64 114 43 1441802 cycle~;
#P newex 31 188 43 1441802 cycle~;
#N comlet Modulation index;
#P inlet 193 39 15 0;
#N comlet Harmonicity ratio;
#P inlet 114 39 15 0;
#N comlet Carrier frequency;
#P inlet 31 39 15 0;
#P window setfont Times 10.;
#P comment 46 214 53 1310730 FM signal;
#P fasten 3 0 9 1 198 57 146 57;
#P connect 9 0 6 1;
#P connect 7 0 5 0;
#P fasten 7 0 9 0 69 82 118 82;
#P fasten 2 0 7 1 119 57 97 57;
#P connect 6 0 8 1;
#P connect 5 0 6 0;
#P connect 1 0 8 0;
#P fasten 1 0 7 0 36 57 69 57;
#P connect 4 0 10 0;
#P connect 8 0 4 0;
#P window clipboard copycount 17;
__________end copy+paste__________

See Peter Elsea's 'Max and FM' tutorial for a clear demonstration of harmonicity and mod index, and how they relate to timbre spectra

looking to design an FM synth like Operator