The Filter – pt 2

We’ve shown you what a filter does and how it does it, and now it’s time to put that knowledge to use!

- Scot Solida

1 Fire up Voltage Modular Nucleus and bring in the CM Filter patch we made last time around. As you may recall, our last experiment was plumbing a sine wave through our filter, revealing that the latter had very little effect on the former. If you’ve read our explanation on harmonics (above right) you’ll understand why.

Last issue we looked at the many functions of a typical filter, using the module included with Cherry Audio’s Voltage Modular Nucleus. We showed you each of the onboard filter types (low-pass, high-pass, etc) and two slopes. We learned how the filter’s ability to carve away selected frequencies make a subtractive synthesis, well, subtractive and how it affects some of the waveforms produced by a typical analogue oscillator.

This month, we’ll use that sculpting power to create some familiar timbral effects.

A filter is at its best used dynamically – simply setting the cutoff frequency and leaving it alone does not make for an exciting sound! Such a static approach surely has used – especially when using a filter as a corrective tool – but the best synth sounds are organic, ever-changing, and when combined with other modules, filters are great for imparting motion and life.

To that end, we’ll call some of the most common modulation sources into play to control our filter over time. A glance at virtually any analog synth, hard or soft, will reveal the two most common filter modulation sources – the humble envelope generator and the LFO (low-frequency oscillator). We’ll continue using the basic synth patch we made last time. If you missed it, load up the preset patch called CM Filter, which can be found on FileSilo.