Creating A Simple FM Bass From Scratch

DX-type FM basses have become all the rage again recently with our rekindled love for all things ’80s! While it’s obviously easy to reach for a DX-preset, plug-in (FM8/ Dexed etc) or a sample, there are also analogue synths offering FM (frequency modulation) of one oscillator via another and it’s more fun creating your own FM sounds! Below, we show you how to get a bespoke FM bass happening on any FM-equipped analogue synth.

These steps can be applied to any analogue/digital 3-osc synth with FM available. Start from an initialised patch so you have a clean slate to work from. On the Voyager, select a blend of triangle and saw for Oscillator 1’s wave shape.

Set ‘amount to filter’ to full, then set the filter envelope for a nice punchy sound, with plenty of snappy attack and no release so it cuts off cleanly. Do the same for the amp envelope. Balance the oscillator levels to taste in the mixer.

Set Osc 1’s octave pitch to 4’ and now turn on Osc 2 and set it to a square wave. We are going to use this oscillator as sub oscillator to bolster the lows. Set the octave pitch to 32’ and keep the frequency at 0.

For some further grit, route audio out of your synth, back into the external input and overdrive to taste. On the Voyager this adds dirt, thickness and weight which is always welcome with FM sounds – they can often sound pretty thin and cold!

Keep Osc 3 switched off in the mixer and set its pitch to 32’ with a triangle/saw blend much like Oscillator 1. Once again, keep the frequency at 0. Switch on the ‘3-1 FM’ switch which enables frequency modulation of Oscillator 1 via Oscillator 3.

Try different tonalities by tweaking the waveshapes on Oscillator 3/1 and using different filter cutoff/resonance settings. Add modulation from an LFO to affect pitch or filter to add further interest. Once recorded into your DAW, you can then effect/process further.