KVR Audio

willdub1 · Post by **willdub1** » Sat Nov 23, 2013 4:52 am

Just as the title suggests, does anyone know how the ratios are suppose to be set in FM8?

Halma · Post by **Halma** » Sat Nov 23, 2013 8:57 am

Hey wildub1,

not quite sure if you wanna know something about FM ratios in general (then look here) or if your question was especially related to set the ratios inside of the FM8 (then I can't help you, sry).

But the first one has some great explanation about using proper C:M Ratios and what sidebands to expect.

Regards
Sebastian

GeckoYamori · Post by **GeckoYamori** » Sat Nov 23, 2013 12:05 pm

The ratios follow the overtone series, so that's an excellent reference to use. The first couple of ratios (1, 2, 3 etc) are all octaves and fifths and such, which gives a more clean and neutral character. As you go higher you start getting smaller intervals like thirds, seconds, eventually even smaller than seconds. Dissonant, bell-like sounds usually use smaller ratios like 2 operators with 5 and 8 respectively. Very high ratios like 12 to 2 gives off a more metallic vibe.

I think the problem with purely academic explanations like the one linked above is that they seem completely severed from a musical perspective.

willdub1 · Post by **willdub1** » Sat Nov 23, 2013 5:24 pm

Halma wrote:Hey wildub1,

not quite sure if you wanna know something about FM ratios in general (then look here) or if your question was especially related to set the ratios inside of the FM8 (then I can't help you, sry).

But the first one has some great explanation about using proper C:M Ratios and what sidebands to expect.

Regards
Sebastian

Thanks. This seems interesting.

willdub1 · Post by **willdub1** » Sat Nov 23, 2013 5:27 pm

GeckoYamori wrote:The ratios follow the overtone series, so that's an excellent reference to use. The first couple of ratios (1, 2, 3 etc) are all octaves and fifths and such, which gives a more clean and neutral character. As you go higher you start getting smaller intervals like thirds, seconds, eventually even smaller than seconds. Dissonant, bell-like sounds usually use smaller ratios like 2 operators with 5 and 8 respectively. Very high ratios like 12 to 2 gives off a more metallic vibe.

I think the problem with purely academic explanations like the one linked above is that they seem completely severed from a musical perspective.

Yeah and it also sucks that there is'nt really an explanation regarding setting ratios or how to set them in the manuel

MackTuesday · Post by **MackTuesday** » Mon Nov 25, 2013 5:34 pm

This guy has some free material that you might find useful.

c_bomb · Post by **c_bomb** » Tue Nov 26, 2013 1:51 am

willdub1 wrote:Yeah and it also sucks that there is'nt really an explanation regarding setting ratios or how to set them in the manuel

There aren't any hard and fast rules as to how to set the operator's ratios.

.5, 1, 2, 4, 8, etc are all octaves so they'll sound the most harmonic when modulating another operator.

I've got a spread sheet at home which calculates the notes and their respective ratios, I could email it to you if you like.

Edit: You can also use operators as waveshapers if you set the ratio to 0.

I'm quite partial to sending operators through operator X then the filter (operator Z) then another operator set to 0 ratio for some fun distortion. Muck around with weird operator wave shapes (formants, etc) as your waveshaper.

BertKoor · Post by **BertKoor** » Tue Nov 26, 2013 8:14 am

willdub1 wrote:it also sucks that there is'nt really an explanation regarding setting ratios or how to set them in the manuel

One picture:

shows it's done in Expert mode.
A random tutorial shows the same:
http://www.fm8tutorials.com/tutorials/c ... fm-matrix/

Jessie_puzzle · Post by **Jessie_puzzle** » Sun Feb 03, 2019 11:09 pm

Hi! I am quite interested that spreadsheet you got there. If ever it's still available.

c_bomb wrote: ↑Tue Nov 26, 2013 1:51 am
willdub1 wrote:Yeah and it also sucks that there is'nt really an explanation regarding setting ratios or how to set them in the manuel
There aren't any hard and fast rules as to how to set the operator's ratios.

.5, 1, 2, 4, 8, etc are all octaves so they'll sound the most harmonic when modulating another operator.

I've got a spread sheet at home which calculates the notes and their respective ratios, I could email it to you if you like.

Edit: You can also use operators as waveshapers if you set the ratio to 0.

I'm quite partial to sending operators through operator X then the filter (operator Z) then another operator set to 0 ratio for some fun distortion. Muck around with weird operator wave shapes (formants, etc) as your waveshaper.

BertKoor · Post by **BertKoor** » Mon Feb 04, 2019 7:01 am

See my sig, MusicCalc does that. Getting ratios is simple. Set middle C to 1000 samples long and divide whatever result gets calculated by 1000.

DJ Warmonger · Post by **DJ Warmonger** » Mon Feb 04, 2019 7:31 am

From the guy who invented the thing:

http://www.burnkit2600.com/manuals/fm_t ... ations.pdf

Starting from very basic maths, all the way up to complex sound design.

c_bomb · Post by **c_bomb** » Sun Feb 10, 2019 3:07 am

Jessie_puzzle wrote: ↑Sun Feb 03, 2019 11:09 pm Hi! I am quite interested that spreadsheet you got there. If ever it's still available.

I don't have it any longer unfortunately. You can however use the formula that BertKoor provided in the second post of this thread to whip one up yourself.

viewtopic.php?t=181854

BertKoor · Post by **BertKoor** » Sun Feb 10, 2019 10:42 am

c_bomb wrote: ↑Sun Feb 10, 2019 3:07 am
Jessie_puzzle wrote: ↑Sun Feb 03, 2019 11:09 pm Hi! I am quite interested that spreadsheet you got there. If ever it's still available.
I don't have it any longer unfortunately. You can however use the formula that BertKoor provided in the second post of this thread to whip one up yourself.

viewtopic.php?t=181854

That's an old topic. Must have been around the samed time I created the MusicCalc web page which still is around today.

Setting Operator Ratios In FM8