CLAVIA DMI AB CLAVIA NORD Rack 2X [75/114] About subtractive 11 synthesis

About Subtractive Synthesis Page 73

11. About Subtractive

Synthesis

Introduction

Subtractive synthesis is one of the oldest and most widely spread forms of synthesizing sounds. It is the

method employed in such classics as the Moog synthesizers, the Sequential Prophet-5 and 10, Arp syn-

thesizers, most Oberheim synthesizers, the Roland Jupiter models, the TB-303 etc; the list is practically

endless. Even new digital instruments such as workstations and sample playback devices employ many

of the basic principles of subtractive synthesis.

So what’s the big deal about the Nord Lead then? Simply another “subtractive synthesizer”? Well, the Nord

Lead is the first modern, digital instrument that combines a faithful reproduction of the behaviour of the

old analog favourites with the convenience and stability of the newer designs.

The purpose of this chapter is to give you a quick introduction to this world of subtractive synthesis as

used in he Nord Lead and its analog predecessors. If you’d like to know more, there are number of text

books on the subject.

The Building Blocks

Subtractive synthesis started its life in modular synthesizers, large cabinets housing separate electronic

modules, connected via patch cords. With the advancement of technology, the functionality of many of

these modules could be put onto one single circuit board. But functionality-wise, subtractive synthesizers

are still built out of the same modules (or building blocks) as they were decades ago.

We will now take a closer look at these building blocks. Let’s first talk about the three that actually create

and process sound:

Oscillator

The Oscillator is actually the only thing in a synthesizer that actually produces any sound, (all the other

modules only shape the sound from the oscillator.) The oscillator is a bit like the string on a string instru-

ment, it vibrates to create sound.

Filter

The signal from the oscillator is sent through the Filter which shapes the timbre of the sound to make it

“bright”, “dull”, “thin”, etc.

Amplifier

The Amplifier shapes the volume of the sound making it “soft” or “hard”, “slow” or “short”.

In addition to these major three modules all synthesizers also have “modulators”, devices that can make

the volume, timbre pitch and other qualities of sound vary continuously when you play a key. It is these

modulators that basically add animation to the sound, taking it from a dull organ drone to a dynamic and

interesting timbre. The two most common modulators are Envelopes and LFOs: