analogue and digital FM. differences/ similarities

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oblioblioblio
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Post by oblioblioblio »

it's quite interesting, the signifance of the root frequency of a tuning system.

to the ear and the mind, the important thing is the ratios that you use to move from one note to the next.

but i guess all physical things have some structural resonances, the body certainly.

432 also lines up with Ancient Indian tuning.
AK
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Post by AK »

steevio wrote:
AK wrote:(quote: start with C = 2hz)

Thats impossible though. That would end up at, c7 = 2048hz, in A/440 c7 = 2093hz. Is it the A/432 that produces c = 2hz? If not, it would be impossible to calibrate a whole studio to a tuning system such as that.
C = 2 Hz is 432 tuning, thats what i was on about.

but while 2048 may seem on paper alot different to 2093, in reality its just 31 cents flat. (theoretically) which is not alot of difference.

its not impossible bro, my studio is tuned to 432. it took me one minute to do it.
you can tune your studio to whatever you want, 432 is considered one of the oldest and purest of tunings, some of the legendary instruments such as the Stradivarius violin are tuned to 432.
440 is totally arbitary, and only been in existence for about 70 years.
Mate, theres a fair bit I know about 432, didnt know you were refering to it then though. But yeah, thats way too OT. But isnt it 32cents detune?

In terms of frequencies and fm experiments, how do I work out the frequencies of notes? If c = 2hz and a = 432, then how can i get the other note values?

Its not important for me to simply detune the master tune, I was an octaves worth of hz values to work with. I only just finished a chart with A/440 frequencies so may as well do one on this too. So if we start at a low octave where c = 32hz and a = 54hz, how do i get the other 10 notes?
steevio
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Post by steevio »

got to go out now,

but, 3 x C = G
3 x G = D
3 x D = A

etc etc....

3 x any frequency is its perfect 5th.

(as near as damn it (within 2 cents))

tuning by ear its 31 cents detune (to my ear)
s.k.
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Post by s.k. »

ok guys i want to put up another fm demo, this time more of a dedicated work, needless to say - kick & bass. i think a sound is worth a thousand words so nevermind noone else puts up stuff - here goes mine:

http://www.sendspace.com/file/wezwtv

about the file - i deny the whole concept of 'mixing' kickdrum + bass, sidechaining and all that BS, thats too rock&roll. my personal choice is mixing by multiplying instead of summing, which at its core FM, i just do it in my own personalized way to an extent. hope you like it, i also made it very simple on purpose, again for demonstration of a technique moreso than a showoff or anything... hope not too simple for your taste, and yeah - feedback pls.

good thread innit? i like it how we can actually be constructive and by everyone sharing his knowledge on stuff we fill the whole puzzle.

@AK - totally go for it man, it is very predictable. being harmonic, inharmonic or whatever the fck you want depends on the C:M ratio (carrier to modulator). 1:1 will give you the harmonics of a saw wave, only with different (and varying!) amplitude of the harmonics (sidebands) - which in turn depends on the mod index (the amplitude of the modulator). 1:2 will give you the harmonics of a square. these are the most simple harmonic ratios of normal form. 1:3, 1:4, 1:5 and every other ratio where C is 1 and M is integer is a harmonic ratio... thats the base.

@steevio - totally agreed on PWM, i am not by any means denying the power of it, just comparing the techniques and their ways of work, pros and cons, for different tasks they are for sure both valid, excuse me if i sound rude at times im trying not to :) .
AK
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Post by AK »

Ah thanks. Knew there must have been a formula for working that out. :P
AK
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Post by AK »

s.k. wrote:ok guys i want to put up another fm demo, this time more of a dedicated work, needless to say - kick & bass. i think a sound is worth a thousand words so nevermind noone else puts up stuff - here goes mine:

http://www.sendspace.com/file/wezwtv

about the file - i deny the whole concept of 'mixing' kickdrum + bass, sidechaining and all that BS, thats too rock&roll. my personal choice is mixing by multiplying instead of summing, which at its core FM, i just do it in my own personalized way to an extent. hope you like it, i also made it very simple on purpose, again for demonstration of a technique moreso than a showoff or anything... hope not too simple for your taste, and yeah - feedback pls.
Is this all done in Max/MSP? The Justsurf audio demo is wicked, I love that kind of FM sound. Yeah the kick/bass one, I didn't quite get what you mean. Is this the same sound but with 2 the decay opened on the 2 and 4?

Test 1 and test 2 are similar to sounds I was getting out of FM8, but I got tons of 'clicks' and the sounds never really seemed to have a clear tone to mean even though in theory, you'd think it would ( being digital ) But Probably down to me somewhere I imagine.

I have been checking out a few youtube videos of analog FM, definitely has more bollox to the sounds and also seems to have a depth and presence I can't hear in digital FM. It's not like I have enough knowledge about FM to argue any points mind you! :lol:

Yeah, we need a few analog FM audio examples.
s.k.
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Post by s.k. »

AK wrote:Is this all done in Max/MSP?
yes
AK wrote:Is this the same sound but with 2 the decay opened on the 2 and 4?
no its not that simple, look at the waveform

FM8 could be ok, i have tested it before but not enough to know in depth how it behaves. yes we definitely need analogue demos!
steevio
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Post by steevio »

will post some analogue demos when my studio is back in one piece again.

i can give you a demo of a Bosch electric drill if you like.

will likewise check out your demo when everything is back on line.
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