For longest time, I was intimidated by synthesizer controls. Terms like oscillators, LFO’s, and envelopes seemed beyond my grasp. Somehow, over time, I figured out a few synth tricks.
As it turns out, there are some basic synth concepts that enable dramatic and useful results. One such concept is the filter. And filter controls are commonly available, even on inexpensive keyboards.
What a synth filter does
What a synth filter does is cut out a certain amount of high frequencies in your sound. Whether it lets just the low sounds through or all the sound through is up to you. That setting is called the filter cutoff frequency. Everything above the cutoff is filtered out, while everything below the cutoff passes through. It basically functions like an EQ low-pass (or high-cut) setting.
A synth’s filter cuts out some of the high frequencies.
So how is the filter cutoff useful?
Filter synth tricks #1 – edit a sound to make it brighter or darker
Sometimes a preset synth sound is not quite right. Pads are a great example. Often, stock pad sounds are too bright. That’s easily fixed by simply lowering the sound’s filter cutoff frequency. You can probably double the number of useful pads in your keyboard with this simple edit.
Filter synth tricks #2 – frequency sweeps
Filter sweeps can create very dramatic and dynamic effects. You’ll need a control knob, either one on your keyboard, or a MIDI knob to control a software synth, like those in Mainstage. In the video below, I use Mainstage’s ES2 synth plugin, which actually has two filters. The macro cutoff control will affect both, so I can map a knob to that macro dial. Then, I can hold a chord and sweep the filter for the effect.
Filter synth tricks #3 – using the LFO for a pulsing sound
This third synth trick is a little more technical, but very do-able. Some synths will allow you to use a low frequency oscillator (LFO) to automate the filter cutoff over time. One application is to move the filter from high to low with the tempo of your song. In the ES2 synth, that’s done in the modulation router. Watch the video below for a quick demonstration.
The Mainstage advantage
The biggest thing to help me conquer my fear of synthesizers has been Mainstage. Being able to see the controls laid out visually on a screen is a huge advantage over scrolling through menus on a tiny keyboard screen. If you own a Mac, I highly encourage you to check out the powerful options that Mainstage offers. The best way to learn Mainstage for keyboard is the Mainstage Keyboard Course. Check it out today!
