2-pole LP/BP/HP/Notch Filter
This is probably one of the last my simple building blocks before I start to post my completed ensembles and/or instruments. And since I described almost all of the building blocks it’s not a problem to describe the completed things. Well, let’s take a look at the filter design which I’ve left as it was in one of my synths, the design is quite optimized because I had no plans to publish my synths until I realized that the number of my ideas is far bigger than time I have to explore it’s actual creative potential, and I need to write them down before another bunch of them kidnapped the time window.

One of the specific features is separate stereo-channels wireless modulation. Of course it’s a pretty exotic feature. Most of synth-builders don’t put a lot of attention to stereo separation. But when it comes to sequencing the stereo tricks sounds quite fat. After all, let’s give some respect to the Creator who has given a couple of ears to most of us
Next specific option is the type fader. The reason I’ve done the fader instead classic switch is simple - why not?. 2-pole filter Reaktor module has 3 outputs and it’s too prodigally to have them unconnected to somewhere.
The structure is simple. And there is a couple of notes I would like to point out. As you may see I used “Pitch to Frequency” modules to modulate the cutoff frequency. There are 2 reasons I’ve done this instead modulating the cutoff frequency directly. First, the cutoff fader has pitch (half-tones) scale which linear modulated (multiplied) with the modulation source before converted to the frequency, that produce logarithmic shaping for the modulation frequency that comes to the 2-pole filter module. That mean basically more deep sweeping for low/mid frequencies. Second, “F” (frequency modulation) input of the 2-pole filter is audio-type, we’re not limited with event timing rate. These notes are, probably, not very obvious, but worth to mention I think.
And finally a couple of words about stereo modulator macro:
The main idea of the stereo modulator is having of one or two modulators and produce scaled reflecting of the signal for an opposite channel, i.e. when Left channel got high value of modulation the Right channel got low one, and vice versa. There is a small file that illustrate it. Basically, the stereo modulator is similar to my standard modulator, the difference is splitting one modulation source (modulation fader/knob) to 2 separate ones (which can be tuned from “the same” to “mirrored”) with “phase inverter” which do the main trick.
Downloads:




December 2nd, 2006 10:12
What exactly is involved in your “phase inverter”
December 2nd, 2006 11:13
Hi.
There is no anything very complicated in the “phase inverter”, but I’ve added the structure picture to the post.