Additive synthesis is based on the theory that any sound can be made by combining a series of sine waves at various frequencies (see the lesson on harmonics for more details). Start adding waves together and you get new, harmonically-rich waveforms. Essentially you’re deciding at which frequencies you want your harmonics and adding them yourself. [...]
Frequency-Modulation Synthesis, or FM Synthesis for short, works differently than what we’ve talked about so far. It uses one wave to rapidly increase or decrease (modulate) the frequency of another, which creates entirely new frequencies that aren’t part of the first two. Don’t worry if that’s not very intuitive; I’m going to break it down [...]
Most of the synthesis methods we’ve talked about so far produce periodic waves, meaning at some point the repeat. Simple waves may go up, then down, then back up again. More complex waves might go up and down a few times, but somewhere there is a repeating pattern. Wavetable synthesis takes advantage of this fact [...]
A sampler doesn’t synthesize sounds so much as it plays back sounds that were recorded from somewhere. The recordings are stored digitally in memory, so they can be triggered instantly when you hit a key on your synth. They can also be sped up and slowed down to achieve different pitches. Sampled waves can be [...]
So far we’ve talked about what synthesis is and various methods used to generate waves. In the “Building Blocks” section we’re going to look at all the different parts of a synthesizer and how they work together to create sounds. When I talk about “parts”, I’m not referring to the actual capacitors, resistors and other [...]
Noise modules are fairly simple. They produce a random electrical signal (noise). They sound like “shhhhh…” Not all noise is created equal, however. There are different types of noise that have their powers concentrated in different parts of the audio spectrum. They are named after colors of light that have analogous power distribution in the [...]
Waveforms generated by your synth don’t have to be simple or random. They can come from recordings. Samplers operate on this principle. Instead of a simple sine or square wave, they use a digital recording as their sound source. Of course these more complex waves can still be pitched up or down (played faster or [...]
Synthesizers don’t just make sounds; they modify them too. There’s no rule that says you can’t use one to modify or mix sounds that come from outside the synth. There are hundreds of places to get electronic audio signals: Grab your iPod and plug it into your system. If you’ve got a computer running a [...]
The voltage-controlled filter is a major part of subtractive synthesis. There are many different ways to design a filter, and although they basically do the same thing, they all sound a little bit different. The filter is the part of the synthesizer that is most responsible for shaping the tones you get out of it, [...]
A voltage-controlled amplifier lets you use a voltage to control the amount of another signal that is allowed through. The higher the control voltage, the more signal is passed. At some voltage level, the entire signal is let through. One of the most common uses of a VCA is envelope shaping. Think about when you [...]
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