The idea here is that instead of having a bass patch with the normal sharp attack and slow decay, we’re going to create a sound with an organ-like on/off envelope, but extreme velocity-controlled analog filter juiciness. But that’s just part of the equation; we’ll get to the rest in a bit. First here are some sonic reference points.
We’ll start with the lead-off track from Depeche Mode’s Violator disc, “World In My Eyes”. This has to be some of the meanest synth bass ever recorded, courtesy of Alan Wilder’s custom MIDI-fied Minimoog/Oberheim SEM rack. It’s a mix of a couple parts, but you can clearly hear the different filter cutoff settings on each note. In a similar vein, the Sneaker Pimps’ “Low Place Like Home” incorporates a slithery gliding mono synth bass that leans heavy on the resonance. And the Crystal Method make use of a similar heavy-on-the-glide, heavy-on-the-resonance type patch in the signature riff of “Busy Child”.
So what of this velocity-controlled bass? Let’s make the patch. I used Arturia’s Minimoog V, an obvious choice for big-time bass, but you can use other virtual analog synths. Because of triggering and glide, some may not work as well as others, but the basic ideas will work. First I used two oscillators split one octave apart, both with sawtooth waves selected. Detune them a wee bit for flavor. Moving to the filter, initial cutoff frequency should be very low; just enough so that a dark but audible sound comes through. Crank the resonance (or “emphasis” in Moog-speak) up to about 60%. Filter envelope amount should be zero. Amplitude envelope controls should have zero attack, zero decay, sustain full up, and release on zero. Ignore the release if you’re using a Minimoog clone.
Now we’ll transform our relatively boring bass patch into something fun. In the modulation routing section, set the source to velocity, and the destination to filter cutoff. Now set the amount to around 50–75%. You’ll need to experiment, but when you play light, the bass should be super dark, and when you really whack it, you should hear cutting sawtooths. The idea is to avoid turning the mod depth up too high, otherwise all of your harder velocities will make for full brightness, thereby compromising your dull-to-bright dynamic range.
Now make sure the sound is in mono mode, i.e., you can only play one key at a time. Different synths use different nomenclature, but just look for the section that has a “poly” or “mono” or “number of voices” setting and set it for “mono” or “one.” Most synths also have options for the mono mode, including “retrigger” and “legato” modes. “Retrigger” means the envelopes will start at the beginning of their cycles with every key press, whereas “legato” mode restarts the envelopes only when ALL keys have been released and a new key is pressed. Set this to “legato.” Finally, since we’re in mono mode, most synths have a switch to give the high, low, or last note hit priority; set this to “last”, i.e., the most recently hit note sounds.
Now it’s all in how you play it. The fun thing is that you can hold your left hand down on a key and hit notes with your right hand at different velocities, radically altering the color of the bass tone. Try adding a heavy dose of glide, and you’re all set to get busy child!