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4. Adding weight to the bass with pitch modulation

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Layering bass sounds and using filter cutoff modulation is a good way to create weight in your low end, but these techniques might not suit the type of music you’re making. Another way to fill out the bass frequencies is to use pitch modulation to sweep the sub. Let’s look at an extreme example of this technique. Mute the LFO bass patch, or load up the Sine bass.als project if you’re starting from scratch here. 2

Bring up the sub-bass Dune CM’s interface and click the Mod Matrix 1>12 button. We’re going to use modulation to sweep the pitch of the sub automatically every time we play a note. Set the second row of the Matrix’s Source to Mod Env, Destination to Osc 1 Semi and Amount to +24. (Audio: Bass pitch mod.wav) 3

This gives us an approximation of a Roland TR-808 kick drum, a sound that’s used for punchy sub-bass in countless dance tracks. The pitch drops from two octaves up to the root note very quickly at the start of the sound, giving the bass a kick drum-like punch. We can control the time the pitch takes to drop with the Modulation Envelope’s Decay knob. Set it to 67%. (Audio: Long decay bass.wav) 4

Let’s incorporate another type of pitch modulation into the sound. Set the third row of the Modulation Matrix to Source: LFO 1, Destination: Osc 1 Semi and Amount: +2. Now both the LFO and the envelope affect the pitch of the sub. Set the Rate of LFO 1 to 7.5Hz to make the bass wobble more quickly. This gives us a sub that, although simple, has a lot of movement and character. (Audio: Wobble sub.wav)