A Subtractive Core One flavour of synth that can usually be found in any software- or hardware-based studio is the trusty subtractive synth. Even in its most basic form it will have an oscillator that can generate some or any of the following waveforms: sine, triangle, sawtooth and square. Following that is a filter, which is used to carve out a tone from the chosen waveform. In reality, though, most modern subtractive synths have features that go far beyond these basics. This has two oscillators, enabling you to blend different waveforms or take your first step into creating something ugly-sounding, using two of the same waveform. The square and sawtooth waveforms are the most immediately gratifying in this respect as they are rich in frequency content, and therefore ideal for creating big sounds. A sawtooth wave is full of harmonic frequencies and sounds quite musical, whereas the square wave contains only every other odd harmonic, giving it a dense yet hollow sound. To get started, select two of the same waveform on your synth either a square or sawtooth. Now use the cents or fine-tuning controls for each oscillator and tune one up by 15 cents and the other down by 15 cents. By pulling them apart you will still hear the central pitch in the middle, but you will also perceive a thickening effect like that of any instrument when double-tracked. Lower values will create a thickening effect, but the tone will still be quite pleasant. We also set the amount of cents going up and down to the same values, so the central perceived pitch stays in-tune with your other instruments. This mimics the detuning of two oscillators saving on the use of other oscillators. This also detunes them equally up and down for you. Another area worth exploring is detuning the oscillators but then separating them by an octave. In particular, moving an oscillator up one octave also gives you a denser top end to play with when it comes to filter and amplitude modulation stages. But these extremes are best used on occasion — for contrast within a collection of other sounds, or within a melodic part. You can try and use other instruments in your songs to aid the parts being played by your synths. Try using the kick or percussion parts in your rhythm track to sync with the rhythm of your synth. If this is a little too much, use higher-sounding elements like high-hats instead Making Waves Many modern synthesizers cater for a lot more than the four simple waveforms discussed so far. Synths such as Massive, Albino and Z3TA — to name but three — provide many more custom waveforms. These instantly offer more variety than the classic set of waveform sounds and can save a lot of time and the need to use multiple oscillators when creating sinister tones. A common trick for making a raspy-sounding instrument is to have one or two oscillators playing high enough to carry the notes of the melody, while a sharp-sounding oscillator waveform a sawtooth, for example plays incredibly low — so low, in fact, that it no longer sounds like a musical tone; it instead sounds like rhythmic ticks as you hear the individual cycles of the waveform repeating. Movements using the pitch bend wheel to one or two octaves can also exploit this super-low oscillator effect. Try holding the pitch wheel fully down at the start of a note and immediately releasing it — you should hear a rasping start to the note, which then jumps to the normal playback pitch, at which the listener can hear the notes being played. Vowel-like filters on a synth sound are easier to discern when used in the higher registers. Applied to lower-pitched elements they can generate a lot of movement in a sound Frequency Modulation And Wavetables Frequency modulation and wavetable synthesis are features common to most modern synths and are excellent ways of getting screeching lead synth sounds and noisy FX. FM enables you to control the pitch of one oscillator via the frequency of another, effectively making the frequency of one oscillator act as a vibrato or LFO to the pitch of another. However, as the frequency of an oscillator is in the audible range and at a much faster rate than vibrato or an LFO, new frequencies are heard from the oscillator being frequency-modulated. This is key for getting dense and coarse-sounding lead sounds. You can investigate the scope of the sounds available through FM by first slowly raising your FM dial. Experiment with both the amount of FM being applied as well as the tuning of the modulating oscillator. Flicking between octaves on the oscillator providing your frequency modulation will give you musical changes in terms of how high or low the new tones being created are. The same goes for changes in semitones at harmonic intervals. To understand what this sounds like, try using just a sine waveform for your modulation oscillator and applying FM to a sawtooth wave. This is similar to the feedback-type of tones guitarists get when they let their guitars ring out next to a cranked-up amp. A quick way to inject movement into a sound before we look at parameter modulation options is to detune the modulating oscillator by a few cents again. This will create a beating tone that will increase in speed the more you detune. Just the slightest amount of noise-based FM will give you a bumble bee-like tone that can work really well on higher lead parts, giving them a unique character while helping them to sit within your mix. Wavetable synthesis is another option for harmonically interesting tones. The process enables you to play a small portion of a longer and varied oscillator waveform file. So, rather than the oscillator being a single squaretooth waveform, it can be a sound moving through various tones, and the wavetable position enables you to slide through various points in the waveform. Try re-amping it through a hi-fi or guitar amp and recording it. This will add the unique characteristics of the amp, speaker, room and mic to use alone or mix in with the original sound. Some synths are restricted to a few hard-wired modulation options such as filter, amp and pitch envelopes, with perhaps an LFO or two to assign to amp, filter and pitch controls. Other synths, however, enable you to assign envelopes or LFOs to pretty much any parameter available. When it comes to moulding an aggressive sound, we suggest you start by looking to modulate the parameters that have the most drastic impact on your sound. This enables you to hear how they will sound when modulating while you focus on tweaking the parameters that work best for this current sound. As part of the oscillator stage, applying some pitch modulation can really help to make things a little meaner-sounding. This is good for adding a slightly uncomfortable feeling throughout a song. Another effective use of pitch modulation is for creating a pitch-bend over time from an envelope this is how you can create those obnoxious-sounding higher lead parts. Create a triangle shape with the attack and decay controls of an envelope be sure to set the sustain level fully down. Set the envelope strength to pull up the pitch by three or four semitones for a very angry sound, or a smaller pitch range to maintain the clarity of each note while still adding a little attitude. The famous Hoover synth sound uses the extremes of an octave or two in pitch modulation. Using a hardware device or correctly mapped MIDI controller will give you hands-on access to the sounds and parameters available in your synth, enabling you to quickly assess presets and tweak them to taste, or build your own sounds from scratch. The non-mechanical timing with sync turned off can really add some funk to an otherwise vicious-sounding synth. Conversely, you can add a harder edge to a soft sound by using a less smooth LFO a square or sawtooth wave , giving more drastic-sounding changes in volume. In a similar way to using small amounts of FM, amplitude modulation can also be used to create a distorted sound. Set the LFO to its highest frequency rate, then pull downwards to hear different distortion tones before it slowly becomes a noticeable flickering of volume change. As the rate of the LFO remains fixed, the pitch of the distortion will also remain the same, so it can be quite effective if you tune the distortion by ear to correspond with a note in your melody, emphasising that particular note each time you play it. A classic technique is to apply a low- or band-pass filter and use an LFO or envelope to modulate its cut-off position. A triangular envelope like that used for pitch modulation earlier is good for getting the sound to quickly approach and disappear again. Or, as with amplitude modulation, you can use an LFO to give rhythmic movement to a part. Increasing the resonance on the filter will give an edgier sound, so this needs to be balanced with how sharp your existing synth sound already is. As with slower-rate amplitude modulation, the most detuned and non-melodic sounds can be given a smoother character via some low-pass filtering. Using amp and cabinet emulation software can help bring a unique tone to each synth part. Taking the metal approach of very high gain levels can yield a nasty sound from even the humblest-sounding synth. An Aggressive Future As you can see, there are many different ways of creating aggressive synth tones — just explore your options on a synth-by-synth basis, as this is why certain models are better suited to certain tasks than others.
