Synthesizer Sound Generation Methods and Representative Models

Synthesizers create sound by synthesizing audio using various methods. In this discussion, we will introduce the different sound generation methods along with representative hardware and software synthesizers for each method.

■ Table of contents

1. Additive synthesis method
2. Reduction synthesis method

Additive synthesis method

First, let's look at the sound generation method called additive synthesis.
This method mainly synthesizes a new tone by combining multiple sine waves of equal or different frequency and amplitude.
As I introduced in my previous blog, the drawbar of an organ is physically easy to understand.
To explain it simply, it is a sound source method that attempts to create sounds that imitate various musical instruments by combining the same notes, lower harmonics, higher harmonics, and so on.
Based on this principle, pipe organs, for example, are said to imitate the sound of wind and string instruments for high notes and percussion instruments for low notes.

Hardware Synthesizer

HAMMOND / XK-4

A new model is newly released in 2023 from Hammond Organ, a well-known organ.
The newly developed MTW2 sound source is used from this model, which not only faithfully reproduces the tone wheel that is at the heart of the vintage organ sound, but also allows detailed setting of its characteristics.
In addition, it has a drawbar, which is standard on all Hammond keyboards and synthesizers!

VISCOUNT / Legend

This is an organ made by Bicount, a long-established Italian manufacturer of electronic organs, although it may not be familiar in Japan.
The feature of this organ is its drawbar, which is almost twice as large as that of a normal organ.
It can switch between two patterns, A and B, and drawbar positions can be set for each.
In addition, the lineup includes not only 73 keys, but also 61 keys LIVE, two different colors black (JdF Signature), and red walnut (Soul).
There is also a single-level 61-key Solo, which is also convenient to carry and operate. This is the perfect keyboard for those who need an organ-specific keyboard.

Software Synthesizer

Native Instruments / Vintage Organs

This sound source has been standard since KOMPLETE 14 SELECT.
Five different organs and 100 presets are available. In addition to drawbars and percussion selection, rotary effects, EQ, and reverb can also be selected.

IK MULTIMEDIA / Hammond B-3X

This software reproduces the Hammond B3, which has been passed down as a famous organ machine.
It not only reproduces and adjusts the sound source, but is also equipped with EQ and effects.
In addition, the Leslie can be modeled from 7 amps and 5 cabinets.

Subtractive synthesis method

Next, let's discuss the sound generation method known as subtractive synthesis.
This method switches sounds by attenuating waveforms with a filter.

Additive synthesis is a method often employed in analog synthesizers. It is based on the three fundamental principles of sound that are crucial for human auditory perception: timbre, pitch, and volume. This explanation is commonly mentioned in discussions about "what is a synthesizer."
Most synths have square wave, sine wave, and triangle wave as standard tone (VCO), and some synths use sawtooth, pulse, and white noise as derivatives.
The volume (VCA) is omitted in most cases, as it is often set by a volume knob or gain.
The main part of this method, the place filter (VCF), as the name implies, switches the pitch of the sound source by restricting the passage of certain frequencies by a filter and letting only a few left frequencies through.
Most models have one or both of two main types of filters: a high-pass filter (which blocks low frequencies through high frequencies) and a low-pass filter (which blocks high frequencies through low frequencies).
There is also a bandpass filter, which is mainly found on soft synths, that allows only specified passages through and blocks out unspecified passages, regardless of whether they are high or low.

Hardware

Analog Synthesizer

MOOG / MOOG Subsequent37

SEQUENTIAL（Dave Smith Instruments） / Prophet-5 Rev.4

Mogg and Sequential (Dave Smith) are two brands that have dominated the analog synth market.
Almost all of the products in their lineup are analog synthesizers.
The most distinctive feature is the amount of knobs, which are intuitive and easy to use as only analog synthesizers can be.

Analog Modeling Synthesizer

KORG / microKORG S MK-1S

ROLAND / GAIA SH-01

Although many people refer to derivative forms such as wavetable synthesizers, these synthesizers are basically analog synthesizers that implement the principles of analog synthesizers using digital circuitry.
By using a CPU board to perform modeling similar to that of analog circuits, these synthesizers have the advantage of being lighter than analog synthesizers. Some models are a little more complicated to operate than others, but they are basically easier to handle than other synthesizers because of their simpler structure.

Software Synthesizer

Software analog synths are basically simple in principle, which is why all DAWs have them as a basic feature. Derivative forms, such as wavetable synths, can perform similar operations.

These are the synthesizers of additive and subtractive methods.
We will continue to introduce more synthesizers in the future, so please refer to them.