‘Genetic’ modulation – fundamental control
Modulation is the motion at the very heart
of bass music, featuring heavily in styles like dustep and neuro bass. Synths
like Native Instruments’ Massive are just as essential to these genres as
Fender guitars were to rock ‘n’ Roll in the 1950s. In the most widely
understood sense, modulation means either delay-based effects like chorus,
flange and phasing, or using, say, an LFO to ‘wobble’ the cutoff frequency of
the filter in a synth. Indeed, modulation is one of the key elements of
subtractive synthesis, where filters take big chunks of the waveform away,
resulting in a final, ‘sculpted’ sound. As those filters are modulated by LFOs
and envelopes, different parts of the sound are boosted or removed, creating
those awesome sonic sweeps and twists that are so much a part of current bass
music.
Modulation
is one of the key elements of subtractive synthesis, where filters take big
chunks of the waveform away, resulting in a final, ‘sculpted’ sound
But the times they are a-changing, and
there are new ways of looking at things. As professor Brian Cox will tell you:
the closer you look at something, the weirder it gets. So far in this cm
Special we’ve used modulation to sculpt our waveforms. But what
if the waveform itself was ‘alive’? What if the modulation occurred deep in the
DNA of the sound, at its most fundamental level? Could we create an oscillator
that was made of modulation? Ladies and gentlemen, welcome to the word
of additive synthesis.
With instruments like the expertly crafted
Razor, we can see modulation working almost behind the Soundwave. We saw in the
distortion tutorial how adding extra overtones to a fundamental sine wave
creates a richness of tone. These extra overtones are called partials. Around
two centuries ago, a French mathematician named Joseph Fourier postulated that
every sound can be broken down into a series of sine waves (partials) that vary
(modulate) in volume over time – so in theory, if we can create a bunch of sine
waves and modulate them correctly, we can make any sound we want!
Using vast and complex calculations it’s
possible to realistically model natural sounds like pianos or cymbals, but as
we’re focusing on bass music here, we’re much more interested in the brutal and
terrifying sounds that can be made by using traditional synth processes like
envelopes and LFOs to modulate these sine waves. In our next walkthrough, we’re
looking at four of Razor’s modules to get a handle on this additive synthesis
sink, with added distortion from the Clipper serving up a real screamer.
Step by step: Building a killer sound
using 320 sine waves and modulation!
- Load up the CM Razoripper start.nrkt
patch. The row of vertical lines in the display that looks like a
barcode represents the 320 sine waves we’re going to be torturing. (Razorripper_basic.mp3)
- The first job is to switch on the Clipper
module on the far right. This is a dirty distortion that will magnify the
effect of the interactions between the sine waves that are about to
happen. Setting the Drive to 60% pushes the signal level
past the fixed clip point and just tickles the meter beneath the Foldover
knob. (Razorripper_clipper.mp3)
- We want more subtle harmonic distortion,
but without destroying our initial sound too much, so we insert a
Bitcrusher plugin. The Clip Level is reduced and the signal is
gently driven, so even though there’s a lot more in the way of overtones,
the original signal is still far from broken. (Razorripper_bitcrush.mp3)
- Our next step is to insert a UAD Neve
1073 EQ. We use this to add further drive and a hefty chunk of mid-range
EQ at about 1kHz; we also add a little extra top end. Now we have a good
core sound that really pops out of the speakers. (Razorripper_neveeq.mp3)
- Left of the Clipper module is the stereo
effects section. Clicking he down chevron at the top left of each module
brings up a menu in the displays above. We select Unisono Noise,
which emulates a chorus effect, and String in the Dissonant Effect
module. (Razorripper_string_unison.mp3)
- Now for the fun stuff. Select the Number
Pitchbend module for Osc 1. This module enables all or some of the
partials to be manipulated in a way that creates the effect of stepping
through the harmonic sequence – like whirling a bendy hollow tube around
your head. (Razorripper_number_pitchbend.mp3)
- There are two little circular meters
below the P Offs (pitch offset) and Amp knobs. Clicking here
brings up a menu of modulation sources. We select En 3 (Envelope 3)
for P Offs, and both En 3 and Vel for the Amp
parameter, which cranks some welly into the Clipper and starts adding dirt
to the sound.
- For the Filter 1 module, we’re going to
use Lowpass Phaser. This is a low-pass filter with the emulation of
a phaser creating a downward-spiraling ‘barber pole’ effect, the speed of
which is governed by the setting of LFO 2. The mod wheel (MW) is
routed to the Cutoff frequency. (Razorripper_filter1_lowpassphaser.mp3)
- Now we select and engage the Format
module in the Osc 2 slot. This is a kind of oscillator/filter hybrid, but
you don’t have to understand it to realize how powerfully it can twist the
sound. We’re using the keyboard pitch (Key) to modulate the Format,
so the tone changes with every note played. (Razorripper_osc2_format.mp3)
- Lastly, we summon up a Pseudo
Pitchbend module for Filter 2. This is one of many esoteric ‘filter’s
in Razor (including the curious Waterbed!), and it actually acts in quite
a similar way to the module we selected for Osc 1. Routing Env 3 to the Cutoff
parameter finishes off our rather aggressive sound nicely. (CM
Razorripper.nrkt, razorripper_in_context.mp3)
