Noob question about FM synthesis

Official support for: u-he.com
RELATED
PRODUCTS

Post

Hi, I recently bought Zebra and am absolutely loving it. :) I'm currently trying to get my head around FM. :shock:

I was wondering if any of you dedicated Zebra users still feel the need to dust off your copies of FM8 from time to time.

I came across an FM thread which compared Zebra to FM8 (and Octopus):

http://www.kvraudio.com/forum/viewtopic.php?p=3392728

Some guy was saying "Zebra can't apply both feedback and a separate modulator to the same carrier ... (or) allow a zero-frequency carrier to be used as a waveshaper."

Do you guys consider these serious limitations? I'd be very interested in hearing what you think.

Cheers
When all else fails, read the instruction manual.

Post

[quote=http://www.kvraudio.com/forum/viewtopic.php?p=3392728[/quote]

There should be no gap in this address, of course. I don't know why one gets inserted after it previews OK. Damn technology :x
When all else fails, read the instruction manual.

Post

That was me!

And yes, I do consider those to be real limitations. There are certain kinds of sounds, easily produced with FM8 or Octopus, that Z2 can only approximate.

There's an "ease of use" factor, too: in FM8 or Octopus, it's easy to tune operators to exact harmonics (say, the 11th partial). In contrast, if you want to tune a Z2 oscillator to the 11th partial, you've either got to dial in a Tune Value of 41.5 plus a Detune Value of 0.50, or to tune the oscillator normally and use the miniscule waveform editor to isolate the 11th partial in Spectroblend mode.

That said, I've ended up using Z2 for all the FM sounds on my current composition project -- because the modular nature of Z2 means it's much more flexible than either of those dedicated FM synths. For instance, I need to be able to modulate LFO rates with envelope shapes. Easy in Z2; impossible in FM8 or Octopus.
If you like 80s retro sounds, check out my latest tune…

Post

Some FM links you might find useful. The first is the absolute basics of FM but very good for getting started:

http://www.gorenfeld.net/lou/fmguide.html

For a more technical discussion of carriers and operators, and how they relate to each other, see this one:

http://www.synthzone.com/midi/yamaha/dx7/2fmsynth.htm

Peace,
Andy.

Post

Thanks for the info, guys! :tu:

Yep, I'm on a steep - well, vertical - learning curve right now, and this is really helpful.
When all else fails, read the instruction manual.

Post

btw, here's one of the zebra fm sounds I'm using -- an example of what fm8 and octopus CANNOT do...

FM-broad-flutters
If you like 80s retro sounds, check out my latest tune…

Post

Very cool! Spookily beautiful...

Erm, if you have the time and inclination, do you mind posting a couple of classic FM sounds Zebra has trouble with?
When all else fails, read the instruction manual.

Post

Okay, these were super-quick and nothing exciting. You could get similar results with Zebra, but you'd have to take a different route to get there.

First, a simple bass patch with one carrier, using feedback to thicken it, and FM by a higher modulator to give it some punch on the attack.

http://pnauert.googlepages.com/ClassicFm8.mp3

Next, a variation on the same patch, with the original carrier fed through a new 0Hz operator (not exactly zero, a little tuning offset, for movement). The 0Hz operator acts as a waveshaper, and I raise the input level going into this operator as the example plays.

http://pnauert.googlepages.com/ClassicFm8-shp.mp3
If you like 80s retro sounds, check out my latest tune…

Post

PaulSC wrote:Okay, these were super-quick and nothing exciting. You could get similar results with Zebra, but you'd have to take a different route to get there.

First, a simple bass patch with one carrier, using feedback to thicken it, and FM by a higher modulator to give it some punch on the attack.

http://pnauert.googlepages.com/ClassicFm8.mp3

Next, a variation on the same patch, with the original carrier fed through a new 0Hz operator (not exactly zero, a little tuning offset, for movement). The 0Hz operator acts as a waveshaper, and I raise the input level going into this operator as the example plays.

http://pnauert.googlepages.com/ClassicFm8-shp.mp3
What exactly do you mean by feeding through a 0Hz operator? Are you setting a carrier at 0Hz and then using the carrier from the first patch as its modulator? Or something else entirely?

Post

lococarlos wrote: Are you setting a carrier at 0Hz and then using the carrier from the first patch as its modulator?
Exactly - except you can get a bit of quasi-detuned animation by offsetting the carrier frequency slightly from zero. The fixed Hz offset in FM8 or Octopus is good for this, but I just used a very small ratio, like 0.008* or something.

*[Edit: probably more like 0.0008]
If you like 80s retro sounds, check out my latest tune…

Post

PaulSC wrote:
lococarlos wrote: Are you setting a carrier at 0Hz and then using the carrier from the first patch as its modulator?
Exactly - except you can get a bit of quasi-detuned animation by offsetting the carrier frequency slightly from zero. The fixed Hz offset in FM8 or Octopus is good for this, but I just used a very small ratio, like 0.008* or something.

*[Edit: probably more like 0.0008]
thanks for clearing that up, that's pretty interesting, I might have to check out whether I can do something like that in Operator. Although I think only one operator has feedback for itself so I couldn't exactly duplicate your patch.

Post

Quick note: Zero Hz FMO modes are planned for some sort of future update... Paul got me convinced here... :)

Btw. still my favourite preset that one can't do with anything else is Drone Darkness Orchestra (movie recommendation: Babylon AD by Mathieu Kassovitz). It also plays the main role in one of the demo songs - can't miss it by name. I love chains like Osc->VCF->FMO or Noise->Comb->FMO.

The great thing about FM is, the less harmonics, the louder the fundamental. Thus FM provides for fat basses without compensating for loss of amplitude due to closing filters in subtractive synths (which can be easily explained with a pencil and a sheet of paper, but not easily in a forum post)

;) Urs

Post

Urs wrote:Quick note: Zero Hz FMO modes are planned for some sort of future update...

8)
If you like 80s retro sounds, check out my latest tune…

Post

Here's a post about FM synthesis with some free FM patches by Michael Kastrup that might help you.
http://www.kvraudio.com/forum/viewtopic ... ol#3071399
Later,
Mike

Post

Once again, guys, thanks for all the help. What a great commmunity! :D

Hmm... So zero Hz FMO modes and harmonic tuning of FMOs will be coming to Zebra at some point. (:hail: Urs) So that leaves it up to me to decide whether it's worth spending money and the time getting my head around another synth for the ability to apply both feedback and a separate modulator to the same carrier... Something to ponder on. After all, Zebra has a huge arsenal of sounds as it is, and I'm certainly nowhere near exhausting that yet!

Paul, are the workarounds to approximate those sounds very involved? I suspect they'll be beyond my abilities for a while, but it'd be good to know.

Cheers,
Neil
When all else fails, read the instruction manual.

Post Reply

Return to “u-he”