If classical music can’t exist without the piano, the same can be said of electronic music when it comes to synthesizers. Generating powerful chords, inspiring leads and other blips and blops that make you appreciate what you are hearing, the synthesizer is a central musical instrument in electronic music. Complex, but fun to use when mastered, your comprehension of electronic music will greatly depend on your ability to understand and master synthesizers.

What is a synthesizer and what does it do?

Simply defined, a synthesizer is an electronic musical instrument, typically operated by a keyboard, producing a wide variety of sounds by generating and combining signals of different frequencies. It is the extensive amount of sound-generating possibilities that make electronic music such a vast and unlimited domain for original creators.

There are some unmistakable principles which make synthesizers what they are. Indeed, the sounds that come out of a synthesizer are all based on the combination of a number of initially basic sounds, that when added tougher deliver a timbre that is rich in harmonics. Once you have generated a sound out of your synthesizer, the possibilities of sound design are endless with built-in tools such as filters, LFO, and amp envelope modulation options.

What are the elements of synthesizers?

Most of the time,  the main elements which you will find in a synthesizer are the same: 

  • Several oscillators which generate sound waves that constitute the basis of the sound you hear
  • A combination of filters which enable you to sculpt your sound even further
  • An amplifier, which will have control over how the sound you are creating evolves in time
  • LFOs & Amp envelopes which control the evolution of the waveform in different ways (pitch, cutoff etc.)
  • A majority of synthesizers will feature built-in effects  (chorus, distortion, reverb, delay etc. )

Basic synthesizer components

Oscillators

Oscillators are doubtlessly the most important element of any synthesizer. Without them, no sound would be generated as it is the waves that are generated by oscillators that produce the basic tones & harmonics of a synthesizer.

When synthesizers were invented, there were only 3 basic types of oscillator waveforms: square, sawtooth and triangle.

Over the years, and with the never-ending development of electronic music hardware and software, new waveforms such as sine, noise and pulse waves were included. Today, some synthesizers will even feature more complex waveforms which are not based on an initially fixed and constant sound-wave patterns.

1. The Sine Wave

The simplest wave shape of a synthesizer is the sine wave. It is based on a fundamental frequency and does not contain any additional harmonics. The usage of this sound wave is very common with sub-basses or in combination with another waveform to add more body to the initial sound.

2. The Square Wave

This sound wave has mellow and hollow sound properties due to the unusual harmonics it producers. If it is always best to use a sample library to incorporate wind instruments in your music productions, the square wave is also suited to that. Moreover, its versatility makes it adapted for any strings, pads, basses or lead sounds.

3. The Pulse Wave 

The Pulse wave is a waveform which can be visualized as a series of rectangles, alternately above and below the horizontal centerline. The relative widths of the above and below centerline portions determine how much even-harmonic content the wave contains. Containing some of the sound properties of the square wave, the pulse wave lets you produce thin reed-like timbres along with wide hollow sounds.

4. The Triangle Wave

The sound of the triangle wave is similar to that of a sine wave. Moreover, as with the sine wave, this type of waveform is often mixed with a sine, square or pulse wave to add a sparkling and glittery feel.

However, visually it resembles more of a square wave, having two linear slopes and consisting of odd harmonics. The triangle wave also shares sound properties with the square waves as its timbre is thin and hollow.

5. The Sawtooth (Saw) Wave

The saw wave is the one that should be used when creating powerful chords. Without a doubt, it is one of the most popular and most used waveforms in most synthesizers.

The main reason is that the timbre it produces has the most harmonic content of all sound waves. Most of the times, if you want to create a complex and rich timbre, you will need a saw wave.

6. The Noise Wave

Noise waveforms are the most untypical waveforms because they generate a random mixture of all frequencies rather than actual tones. The less known ‘pink’ noise is heavier than the more common ‘white’ noise. Noise can be employed for a significant amount of reasons, the main ones being making a sound more percussive or using it for a sweep/FX sound.

Filters

The filter section of a synthesizer is where your sound will be routed for additional sound design. In subtractive synthesis (a technique we will evoke later, which consists of removing frequency content), filters can be used to remove undesired frequencies to shape the sound which is desired.

Therefore, filters must be of good quality to give you an extensive amount of sculpting options. Usually, possibilities with the filter section are extensive and various filter options will be featured. These include low-pass filters (the most commonly used), high-pass and bandpass filters. Sometimes, synthesizers will feature notch and comb filters.

The unit used to measure filters are dB transitions with the less elevated one being 6 dB (single-pole filters). Two-pole and four-pole filters are mostly used by music producers. These equate to 12 and 24 dB filters.

The Amplifier section

The amplifier section on a synthesizer will determine the way your sound will evolve over time. attack, decay, sustain and release settings will let you shape your sound the way you want to.

1. Attack

The attack parameter corresponds to the time the sound-wave takes to be played.

A longer attack time will make your sound “fade in”, whilst a short attack time will make the sound you generate snappy and plucky depending on the sustain and release settings.

Most of the time, a very short attack time is employed. A few exceptions are pads and sweeps.

2. Decay

The second parameter in the amplifier section determines how fast a note takes to decay in volume.

A good way to picture this parameter is to think about when you hold a note. If the decay setting is low, the sound will “fade away” quickly. If not, it will be punchy and present. The time the initial peak takes to fade away from the attack stage to the sustain level is known as the ‘decay time’.

3. Sustain

The third setting of the amplifier section is the sustain time, the period after the initial attack and decay determines the length of the note.

Decay and sustain are related in the sense that if the sustain level is set to the maximum, no decay setting will have an effect.

On the other hand, if there is no sustain level at all, the note will be dependent on the decay settings.

4. Release

The last setting of the amplifier section is the release period. This setting is dependent on sustain as it corresponds to the time the sound will take to fade to silence once you have played a note.

A release setting set to zero will make your sound stop immediately after it is released. If the highest value is set your sound will fade away slowly. However, if sustain is set to zero and release to the maximum setting you will only hear a click.

As you have seen, the different settings on a synthesizer are linked and one setting can affect the extent to which you can utilize the other settings. Therefore, sound design and shaping a unique sounds takes a lot of time and tweaking to figure out what sounds best.

Modulation

If basic sound design such as the combination of the sound waves we mentioned above can produce satisfying results and unique sounds by the modification of octave settings, filters or pitch, modulation is what will really take your sound to the next level.

Modulation is a concept which applies to physics too and can be simply defined as “the process of varying one or more properties of a periodic waveform, called the carrier signal, with a modulating signal that typically contains information to be transmitted”.

In a synthesizer, there are two main outlets for modulation: the amp envelopes and classical LFO (low-frequency oscillation) modulation.

1. Amp envelopes

Amp envelopes have limited modulation options in the sense that they can’t modulate the initial sound based on a waveform in the way an LFO does. Nonetheless, on their own, they can still modify, cutoff options, pitch, resonance, volume and panning. Paired with LFOs they can prove to be even more useful. 

2. LFO oscillators

LFO oscillators are used to modulate other synthesizer parameters such as pitch, filter cutoff, distortion, volume or panning to introduce additional movement into a sound. All of these processes can produce very interesting results. 

One of the main parameters which are associated with LFO is waveforms. As with the synthesizers’ original sound-waves, you can determine the form of the signal that will modulate the initial sound (saw, triangle, ramp etc). Alongside these, an LFO will include a rate control, the gain and the offset (sometimes).

The number of modulation options that are offered will entirely depend on the synthesizer’s capabilities. It is always good to have more LFOs, destinations and modulation options to extend your creative options. Sometimes, with analog synthesizers, you will have a great amount of “patching” options as on the image below.

Effects

Finally, depending on your synthesizer, some effects will usually be included. Hardware synthesizers need to have some form of digital signal processor (DSP) to permit the inclusion of effects. 

More high-end hardware synthesizers will feature a vast array of effects such as chorus, distortion, delay or reverb and even more complex ones. However, it is not rare for entry-level synthesizers to include basic effects such as delay or distortion.

Conversely, software synthesizers often come with a large amount built-in effects, even if some music producers prefer to use external plugins or the ones that are included in their DAW due to their higher quality.

What is the difference between hardware and software synthesizers?

Hardware synthesizers are physical synthesizers which are sometimes more expensive but give you the possibility to create without a computer.

Software synthesizers are computer programs that let you have access to the same creative options as on analog synthesizers with the limitation of having to use a computer in order to do so.

Software synthesizers mostly replicate hardware synthesizers. Therefore you will find the same functions with the flexibility of programming and sound design. Some people prefer a hands-on approach. Others like to be able to have a tactile approach to making music.

However, the debate about “software vs. hardware” synthesizers has been going on for decades with some saying that the latter is delivering a more qualitative and high fidelity sound.

Nonetheless, with the development of computers, extremely capable software synthesizers such as Xfer’s Serum or Reveal Sound’s Spire have been manufactured. Moreover, with a computer, you can have access to more advanced options at a less elevated price.

What are the different types of synthesizers?

The diagram above illustrates the different types of synthesizers which exist. As you can see, it is a rather exhaustive list. Under the hardware and software division, there are also different type of synthesizers (FM Synthesizers, AM synthesizers, hybrid synthesizers etc.), which utilize different forms of synthesis.

Synthesis simply implies the combination of sound waves and the ways these are modified. In music production, you will often hear recurrent concepts such as additive synthesis or subtractive synthesis.

Synthesizer and synthesis options are extensive and each will provide a different touch to your musical creations. However, on most of them, you will find most of the subtractive synthesizer functions we have listed above.

What are some tips and techniques to master synthesizers?

One must not forget that synthesizers are a musical instrument and electronic music is a musical genre. Therefore one of the best assets you have (if you have not already) is to learn more about music theory and improve your skills in piano playing.

Software synthesizers might be the easy option considering how easy it is to use one on your computer. Nonetheless, hardware synthesizers have the advantage to give you a hands-on approach which will automatically make you feel more at ease with any synthesizer.

More often than not, hardware and software synthesizers provide detailed manuals and instructions for your synthesizer of choice. Alongside to simply reading these, we recommend that you spend time applying what you just read and practice. Your goal should be to learn each of their functions and how they relate.

Finally, with the number of resources that are available today, there is simply no excuse for why you are not increasing your knowledge about synthesizers. Forums, youtube tutorials and even buying books about synthesizers will only improve your knowledge of the most important electronic music instrument.

Conclusion

Synthesizers come in different shapes and with different functions. However, the principles behind their functioning are the same for most of them: sound-waves, amplifier sections, filters, modulation and effects being their essential components. Most of the subtractive analog and hardware synthesizers you will use will include these functions.

However, with the constant evolution of capabilities and methods to produce electronic music, in recent years different and more unusual forms of synthesis such as granular synthesis and sampling (which don’t rely on the aforementioned principles) have become more popular. If you are interested in what the best synthesizers on today’s market are, we have already compiled a list of those for you.

To conclude, the tips and techniques we have featured to improve your knowledge about synthesizers should encourage you to practice for hours. It is only by improvising with the combination of different sound-waves, filtering, modulation and the application of effects that you will produce interesting synthesis results. In turn, the original sound design you have produced can only lead you to the creation of a  “killer track”.