Filter

loopman · Post by **loopman** » Tue Aug 23, 2016 2:51 pm

Hello,
there would be a way to achieve an FM Filter on my Radias?

Thanks a lot

OpAmp · Post by **OpAmp** » Tue Aug 23, 2016 10:20 pm

Hi,

What exacty do you understand under FM Filter?
Virtual patches will help you most likely. Route one to the cutoff of the filter and use as source of the patch an LFO, or keytracking, depending on what you understand FM.

Good luck.

Citizen Klaus · Post by **Citizen Klaus** » Tue Aug 23, 2016 11:37 pm

If you mean audio-rate FM of the filter, the RADIAS doesn't really do that. The best you can get is a fast LFO.

That said, the sorts of timbres you can create by audio-rate filter FM can easily be achieved through other means on the RADIAS. Do you want to fuzz up your sound a bit, like you'd get with subtle audio-rate FM at lower resonance settings? Use some pre-filter drive. Do you want to do audio-rate FM of a sine oscillator, like you'd get with a filter at high resonance settings? Use the Cross or VPM options for Osc Mod with Osc 1 set to a sine.

loopman · Post by **loopman** » Wed Aug 24, 2016 3:02 pm

I have in my mind something like this:

https://www.youtube.com/watch?v=WBn3vk2UZeg

or

https://www.youtube.com/watch?v=B3_m6qLsTc8

or

https://www.youtube.com/watch?v=C4S46Y9Du3U

It seems that my Radias Filter section has parameters like Cutoff, Resonance,Eg and Keytrack but not a Frequency (FM) parameter

OpAmp · Post by **OpAmp** » Wed Aug 24, 2016 9:54 pm

Hi,

I've not seen any filter with FM modulation to be honest...

The first video describes what I mentioned in a previous post. In fact I would call it cutoff modulation, meaning the cutoff frequency is modulated by another oscillator. In the particular video, it is done by an LFO (low frequency oscillator). As said before use a virtual patch on the radias to route the LFO (source) to the cutoff frequency of the filter (destination). Don't forget to turn up the modulation intensity of the virtual patch. Further on, play with the initial setting of the cutoff frequency and the parameters of the chosen LFO for modulation. Possibly you want to set up a second virtual patch to modulate the resonance of the filter as well.

By the way, the example in the first video is not that interesting in my opinion. The initial oscillator is a sine wave send through a modulated filter. As the spectrum of a sine wave is only one spectral line, the modulation is in fact more or less the same as modulating the amplitude of the sine wave. More interesting results can be achieved by starting with a waveform with more harmonics like saw or square. The cutoff modulation will change the harmonic content and thus the waveform continously.

Have fun!