Comparing Exponential, Linear, and Through-Zero FM

[@OmriCohen-Music]

Here's an introduction to FM synthesis - kzbin.info/www/bejne/j6XOgKd5mJZ2bpY 00:00 Introduction 01:00 - Exponential FM 12:05 - Linear FM 19:10 - Through-Zero FM 20:58 - Example

[@GeorgeLocke]

Day 3, Omri had 8 mushrooms. Day 4, Omri had 16 mushrooms. Day 5, Omri forgot what day it was.

[@OmriCohen-Music]

Oh yeah :)

[@pardaq24]

"So here's a piece of paper." Nobody: ... Omri: V E R Y N I C E

[@sh0ckvalue989]

I love having a deeper understanding of WHY the oscillators sound the way they do. Thank you for this.

[@OmriCohen-Music]

Yeah, I find it fascinating!

[@brianbergmusic5288]

I am grateful for this lesson. In my travels, I have been enjoying my Mercury-6 license (a software emulation of the Jupiter-6), and the cross-mod is a form of analog fm. The cross-mod does not seem to be a zero-fm circuit/algorithm. For my purposes with the Mercury-6, not having a zero-fm in the cross-mod is fine if the user: 1.) Does not need a fixed pitch (i.e. sound fx or drums). 2.) Does not need the originating timbre to change via the cross-mod (not using the envelope on the cross-mod). Now I know why a zero-fm circuit would be beneficial and also why phase-modulation was invented (which is the form of fm used in the Yamaha DX-line of digital synths). In addition, I can also see another reason why someone would wish to explore modular synthesis. Thank you for passing on such useful knowledge. [edit] I will pose one question. Is there any resources that would compare zero-fm to phase-modulation?

[@NBSStudioMusic]

The best FM explanation I ever saw

[@OmriCohen-Music]

Thanks!

[@yasiin_miim3278]

I just love your explaination with mushrooms!

[@sillysquirrel9979]

Drunk game: 1. open any omri video 2. drink every time he said "very nice"

[@maracuder]

I was always wondering, what through-zero would mean. Now, thank you for your really comprehensive explanation, now I understand the concept.

[@OmriCohen-Music]

I'm really happy it was helpful :)

[@ndf3]

Enlightening video about synthesis AND psilocybin tolerance

[@CinematicLaboratory]

With too much mushrooms, the days will also get longer :). Super cool explanation!

[@exoner6110]

From time to time I have the need to watch videos like this one again to get back-grounded to the roots of what its all about in modular. The best way to keep things simple and effective is to know about the basics. All these feature rich, mighty and "deeeeep" modules are nice to play with for a short while (like a toy), but when it comes to serious patching, most of the times I end up with the modules, that offer limited functionality but a clear design. This is why I love the fundamental modules supported by a few collections, offering functionalities that cannot be patched with the fundamentals. Videos like this one help a lot to get the most out of basic modules and to make them sound amazing. Thank you so much for sharing your knowledge, Mr. Cohen.

[@OmriCohen-Music]

I appreciate it, thank you!

[@rnx317]

seriously one of the best ressources on modular in general - thanks for the good work my man!

[@OmriCohen-Music]

I appreciate it!

[@stephencrane561]

Brilliant explanations and straightforward examples - thank you.

[@OmriCohen-Music]

Glad you enjoyed it!

[@tunefulsensation3044]

I totally didn't know that I could use FM synthesis without minding about tuning issues. I should have watched this much, much earlier. This is a brilliant video!

[@OmriCohen-Music]

Glad I could help!

[@leonardovelazquez1029]

I understand now thank you!

[@OmriCohen-Music]

Glad it helped!

[@screenslaveuk5308]

Great explanation, very clear. I now understand why it sometimes goes badly wrong ...

[@OmriCohen-Music]

Thanks! Yeah, it's super interesting.

[@Leo_Wieber]

Thanks a lot, you are explaining extremely good and the Topic becomes very clear !

[@OmriCohen-Music]

Glad it was helpful!

[@BoardgameBaker]

When Omri puts on his teacher hat KZbin listens. Very educational, great stuff!

[@OmriCohen-Music]

Cheers!

[@luiscoderapuzo]

I should have seen this video years ago, thank you very much!

[@OmriCohen-Music]

Glad it was helpful!

[@derekholland3328]

thanks for explanation, never knew differences.

[@OmriCohen-Music]

Happy to help!

[@PargusAuriga]

Amazing explanation!

[@OmriCohen-Music]

Glad it was helpful!

[@Steve.Benedict]

Awesome. I didn't realize the FM inputs were different on some of these oscillators but wondered why they didn't behave the same. Now I know why :) Should be easy to tell the difference now just by listening, I think...

[@OmriCohen-Music]

Glad I could help! Cheers!

[@vizion9680]

Fantastic video Omri I learned so much about FM thank you!

[@OmriCohen-Music]

Thanks so much!

[@veets1891]

Thank you for this thorough and insightful illustration.

[@OmriCohen-Music]

Glad it was helpful!

[@harrisonfived4966]

Thanks for your work Omri, for guys like me who knew little of this stuff before VCV Rack your videos are invaluable :)

[@OmriCohen-Music]

Hey, that's great, thank you so much!

[@scottkc2cad733]

Boy that really shed some lite for me....And thanks for the pointer on the head phones the other day.I should be getting them tomorrow .....Scott

[@OmriCohen-Music]

Oh that's great! Let me know how you like them :)

[@StudioSixPlusOne]

nice examples, your examples make understanding easy

[@OmriCohen-Music]

That's great, thank you!

[@juniorbonner]

excellent and informative

[@OmriCohen-Music]

Glad you liked it

[@persywho5863]

you will never be the same after day 6🍄🥺

[@OmriCohen-Music]

True...

[@andygrichting]

nice one, spot on explanation and easily understandable. thanks for sharing

[@OmriCohen-Music]

Glad it was helpful!

[@FourTetTrack]

Mushroom algebra, best algebra :D. I love your videos Omri, Thanks for sharing them!

[@OmriCohen-Music]

Glad you like them! Thank you!

[@LYFoulidis]

I can see clearly now. Thanks!

[@OmriCohen-Music]

That's great, thanks!

[@devimckarof7558]

Priceless information, Thanks Omri ^_^

[@OmriCohen-Music]

Glad it was helpful!

[@PfhorShark]

very nice! I wish the mushrooms grew exponentially like that in my area ;) you are such a good teacher, thank you so much for your videos

[@OmriCohen-Music]

Thank you very much!

[@Jimantronic]

Beautifully explained, thank you :)

[@OmriCohen-Music]

Glad it was helpful!

[@sir_williamW]

Thank you!!!!

[@OmriCohen-Music]

Cheers!

[@PspiralifeTutorials]

Great video! well explained thank you !

[@OmriCohen-Music]

Thanks so much!

[@GeorgCarlson]

excellent as always, thanks!

[@OmriCohen-Music]

Thanks so much!

[@ShapeNoise]

The only way out is THRU ZERO 🙏

[@ZuluEchoRomeoOscar]

Ain't that the truth...

[@chemicalBR0]

who knew that FM would need so many mushrooms and so much paperrrrrrr :)

[@OmriCohen-Music]

The only FM is mushroom FM...

[@7177YT]

I was intruiged by the through zero comcept since I stumbling over Divkids videos on oscillators using it. Thank you for bringing the idea to rack. (;

[@OmriCohen-Music]

Oh man, this whole FM thing is super exciting!

[@7177YT]

@@OmriCohen-Music agreed! (:

[@Val_Cla]

You have a ukulele ! I have one too

[@OmriCohen-Music]

Still trying to figure out how to tune it...

[@Val_Cla]

@@OmriCohen-Music mine is G lowC E A , but you can also try some open tunings ! Slide ukulele can be interesting too, i tried that a few days ago :)

[@7177YT]

+1 for ukulele lovers (:

[@markovchains573]

Very interesting!

[@OmriCohen-Music]

Thanks!

[@GeorgeLocke]

Also worth mentioning phase modulation, which, iirc, is how the DX synths worked. Submarine has some oscillators that allow phase modulation, and the relatively new mini oscillators from BogAudio can do it too.

[@GeorgeLocke]

Phase modulation being different from phase distortion. Phase modulation: Sin(f1*t + A*sin(f2*t)). Frequency modulation: sin(f1*t*(1+ A*sin(f2*t))).

[@GeorgeLocke]

Phase modulation sounds identical to through-zero linear FM, though, doesn't it? So maybe just an academic distinction.

[@OmriCohen-Music]

Good call! Thanks!

[@KrikIDDQD]

​@@GeorgeLocke They are identical if the modulating signal is a sine. If the modulator has a different signal, then the results begin to differ. Phase modulation appeared as a way to optimize the frequency modulation algorithm (because it is easier to implement, more stable and requires less computing power). However, when FM synthesizers with interchangeable waveforms began to appear (like TX81Z and AdLib), then the whole catch surfaced, lol.

[@GeorgeLocke]

@@KrikIDDQD very cool, thanks!!

[@JanDTio]

Big light on an obscure theme, thanks, Omri! I am just wondering how one can know the type of FM oscillator except by trial and error?

[@OmriCohen-Music]

Yes, it's an exciting subject! Well, the manual is your friend I guess... And if there's no manual then yes, trial and error.

[@loopinnerthe]

thank you so much. you have opened my mind to fm and through zero and explained its effect. but how do these clever oscillators do negative frequencies? do they just reverse the sign so -30Hz becomes +30Hz?

[@OmriCohen-Music]

I'm happy it helped :) About the frequencies, they don't do negative frequencies, they invert the signal and bring it up the frequency range so, for example, if it goes 30Hz "bellow" zero, it will be inverted and will go to 30Hz. Does this make sense?

[@loopinnerthe]

@@OmriCohen-Music gotcha. thanks.

[@adamsmith7058]

@@OmriCohen-Music Trying to remember the theory here, isn't negative in this context just inverting phase?

[@XiXora]

If you want to save the world and if you like to draw. Perhaps drawing on your table with a white board marker will work? Although, maybe a wipeable vinyl mat if you like to keep your desk clean along with the look of the video. I do love the explanation of how this works. That Linear A-HA moment was great and now I know why you like FM-OP so much!

[@OmriCohen-Music]

Man, you're totally right, but I couldn't find anything now that everything is closed. On the positive side though, my son used those papers to draw on them :)

[@kionazaki8892]

thanks

[@OmriCohen-Music]

Cheers!

[@fritsvanzanten3573]

Interesting video. Sadly, the Woldemar is not supported anymore (you can't add it anymore). The input you used to demo the linear FM has no name, how did you know it was linear?

[@OmriCohen-Music]

Thanks :) Yeah, Woldemar is still not in the library but its on its way I hope. About the FM input,. just to make sure, I contacted the developer.

[@studio48nl]

With vcv rack you don't have the issue of DC offsets you might experience with hardware (analogue) VCO's modulating. Any tip on that? Besides an offset module, I have heard one could use a highpass filter?

[@OmriCohen-Music]

Well, yeah. If you think about it, DC offset is just voltage that has either a very low frequency, or it has the frequency of 0Hz. If you high pass everything below 20Hz, all of those signals will be filtered out. That's how a DC blocker works actually, and that's why you need a DC coupled interface for sending pitch and LFOs and such so they don't get filtered out. Does this make sense?

[@studio48nl]

@@OmriCohen-Music yes, a bit. But I'm still wondering if it would do any good with '0 hz'. SO theoretically, if I would chain a wave (VCO or LFO) through an offset generator through a HPF, the offset is gone? I need to try this...!

[@OmriCohen-Music]

@@studio48nl Yeah, a HP filter should get rid of any offset. of course, it might also effect the sound depending on how low it will go...

[@PspiralifeTutorials]

Basically, if you want normal mushrooms, use Linear through Zero FM. But if you want the effect of infected mushroom, use exponential FM. HAHA!

[@OmriCohen-Music]

You got it! :)

[@kp8923]

@7:59 Wow, that extra oomph you put on the rolled R in "piece of paper" reminded me of Piece of Paper by Amon Tobin. Haha. Any chance you're a fan?

[@OmriCohen-Music]

Wow, that's an amazing track! Thanks for this :)

[@kp8923]

@@OmriCohen-Music I thought you'd appreciate it if you weren't familiar. Take care.✌️

[@rubbaclaymo2822]

cant find any videos on exponential thru zero. does it just not exist?

[@OmriCohen-Music]

Well, I'm pretty sure something like this cannot exist because you will never really reach zero...

[@rubbaclaymo2822]

@@OmriCohen-Music good point and a tough maths reality check for me

[@karmafxify]

Naive Exponential FM will not cross 0Hz. However, if you correct for the Exponential FM detuning you will need a Through-Zero oscillator, just like in the Linear FM case. I've written a paper on this subject, which list the formulas for corrected Exponential FM tuning: karmafx.net/docs/karmafx_DAFx2020_paper_61.pdf It also explains the differences between Linear FM and Phase Modulation.

[@chitlun]

And by day 6 things were getting quite psychedelic 🤪 👍 ✌️

[@OmriCohen-Music]

Oh yeah!

[@blueconcretezebra]

Hungry now...

[@theropodfx436]

Doesn't the Bogaudio FM module actually use Phase Modulation instead of Frequency Modulation? If you run the same scenario of plugging your sequencer CV into the FM input on FM-OP, the only thing you'll hear is some little clicks at the note change. No change in pitch whatsoever because it's just changing the phase rather than the pitch. I think most linear FM synths are actually using phase modulation, but they still call it FM.

[@OmriCohen-Music]

Well, I'm pretty sure that most of the time, FM in the digital realm is actually Phase Modulation, but we just call it FM. I'm not 100% sure though, but the important thing is the result I guess.

[@theropodfx436]

I think that Lindenberg module is one of the only times I've seen digital FM that's actually linear FM and not Phase Modulation. Good find. In practice I don't think it makes a ton of difference unless you're feeding it a square wave.