Contrary to the effects I covered in “Part 1” of this lesson, in “Part 2” I will deal with modulation effects that alter sound in ways that one might call dramatic and bizarre.
Although these – more or less – “advanced” effects have been on the market for years, they are increasingly evident in contemporary music genres.
Here are 4 exotic modulation effects that producers find very valuable.
A ring modulator is a popular tool that affects both frequency and amplitude. It mixes two waveforms together, thus adding frequencies to the output that are the sum and difference of the frequencies present in each signal. These “sum and difference tones” are often more prominent than the original signals. It is also unlikely that they will be harmonically related (since addition/subtraction is linear and pitch is perceived non-linearly). The result is a rich, unique texture – quite inharmonic and clangorous (like metallic bells).
Out of the parameters in a ring modulator, the most significant is the “frequency” of the waveform that is being mixed with the carrier. In most cases, it is accompanied by dry/wet and phase parameters as well as additional oscillators.
A resonator, generally, is a unit that affects tone by emphasizing particular frequencies. They take an incoming audio signal and run it through a series of filtered delay lines. When these delay lines are mixed with the original dry signal, it multiplies the amplitudes of certain frequencies again and again. Resonators allow you to create a sustained tone out of non-sustained sounds. You can even achieve “vocoder-like” sounds by tuning the parameters just right.
One example of a late and more advanced resonator unit is called Resochords. Resochords features more parameters and options for customization. It allows several comb filters to be implemented and individually tuned to produce a selected chord (see blog: Diatonic Chords). The results are most interesting on percussive content (like drums) because they force Resochords to generate “new” harmonic content spontaneously.
The vocoder is, shall we say, one of the most disruptive inventions to hit the music production industry. It has strongly influenced contemporary music and can be recognized by its distinctive robotic, “talk-box” sound.
A vocoder is an audio processor designed to alter the human voice. It is most commonly implemented as a real-time A-D-A converter/processor; inputting a human voice, disassembling its qualities, and turning them into a stream of digits to be modified. Some vocoders can also be used as an insert effect, like a “resonant” EQ. In this implementation, the vocoder imposes the characteristic peaks and noise components in speech sounds called “formants” onto the input via filtering.
Granular synthesis is a technique that rapidly sequences small bits of sound (called grains) over time. It is great for creating soundscapes and other ethereal music. Typically, each grain is between 20 and 100 milliseconds, but they can be longer/shorter. Grains that are shorter are often perceived as clicks. This can be a desired sonic effect for experimental sounds. The silence between grains is known as “intergrain time” and can be customized. In addition, each grain has its own parameters for control such as envelope shape, length, pitch, and amplitude. Grains can be performed mono-phonically or poly-phonically, with or without delay, with a programmed or a random sequence. Imagine the intricate, astonishing sounds you can uncover with this tool.
PRACTICAL USE & AUDIO EXAMPLES
Ring modulator – popular today as an insert effect in samplers and DAWs, used by producers on countless sources from guitar to synths.
Perhaps the best example of this application would be on a short synth sequence. I automated the frequency & LFO speed parameters for some extra movement.
Pad Clean with Ring Modulation
Resonator (ResoChord) – could be applied to a variety of sound sources to add tasteful harmonics (mentioned earlier) and/or build a chord out if one note.
In this example, I processed a vocal recording with a resonator.
Vox with Resonator
Vocoder – widely known as the “robotic voice” effect. It is perhaps best represented on a vocal recording.
Vox with Vocoder
Granulator or granular synthesis – also exemplified effectively on vocals. By time stretching, pitch shifting, and manipulating the recording on a granular level, you will experience radical psychedelic change.
Vox with Granulator