Synth Programing – Korg MS20 Lesson 2

Synth Programing – The Filters

In the last video in this synth programing series the oscillators were discussed and are responsible for creating the actual sounds. In the following video let’s look at the filters. The filters modify the tonal quality of the sound.

The Korg MS20 has 2 filters, a low pass filter (LPF) which as the name suggests allows or passes low frequencies through and cuts or removes high frequencies. The frequency cut off control setting determines the frequencies to be passed and which should be cut. It behaves in a similar manner to the basic ‘tone’ control on a simple radio, therefore as you start to turn the filter control the sound becomes more muffled, as the higher frequencies are being cut. The high pass filter (HPF) does the opposite to low pass filter in that it cuts the low frequencies while passing the high frequencies, and again, the frequency control setting determines which are cut or passed.

Synth Programing - Korg MS20The two controls below each frequency control are known as ‘resonance’ or ‘peak’ controls, and what they do is to boost or amplify the cut off point set by the frequency controls. This produces a ‘whistling’ effect, the pitch being determined by the frequency control, so it is possible to tune it to match the not being played for some interesting effects. Essentially the resonance effect is picking out and amplifying the harmonics of the sound. Be careful as to how much you turn up the resonance or peak control as too much can produce a very piercing whistle which can be quite painful to the ears.

Another filter type is the Band Pass filter that can really enrich our synth programing arsenal, and this allows a range of frequencies through. Some synths have a band pass filter setting with a frequency control, however the range of frequencies is often set and you cannot adjust this. One of the big advantages of a true analog synth like the Korg MS20 is the possibility to set up both the high and low pass filters to work together producing the band pass filter effect. Add some resonance to both these filters and you really get a very rich sound as Jose demonstrates in the video.

Enjoy using your filters to full effect, but watch those resonance control settings. More to come on this Synth Programing mini course.