Hello, Friends! On the previous topics we talked about how to record live instrument and MIDI in your MIX. But today we won't speak about instruments or samples but about synthesizer - digital instrument, that have own unique sound. I would like to explain the usage of the 5 most important synthesis modules: Oscillator, Filter, Amplifier, Envelope, and LFO on the example of ES2 in Logic 9 Pro.



Create a new software instrument track and set the input to the ES2. The synth will pop up automatically. 



Oscillator 


An Oscillator generates a sound. Its task is to create a waveform which will produce a different sound depending on the shape of the waveform. The oscillator does this continuously. The rate at which it generates each cycle of the waveform is what we hear as pitch.



The most common oscillators are:


1. Sawtooth waves, also called saw waves, have a very strong, clear, buzzing sound. A sawtooth wave can be made by adding a series of sine waves at different frequencies and volume levels.


2. Square waves have a rich sound that's not quite as buzzy as a sawtooth wave, but not as pure as a sine. Chip-tune and old video games tracks are made almost exclusively from square waves.


3. Pulse Wave - a variation on the above, the pulse wave is half as wide as a square wave, and has the unique ability to have its width modulated (called ‘Pulse Width Modulation').


4. Triangle waves sound like something between a sine wave and a square wave. Like square waves, they contain only the odd harmonics of the fundamental frequency. They differ from square waves because the volume of each added harmonic drops more quickly.


5. Sine waves look similar to a gentle wave in a bowl of water (like a horizontal ‘S'), moving up and down with no abrupt starts or stops., this produces a mild, soft tone.


6. Noise waves are irregular and they do not have a repeated pattern. Noise generators output all frequencies distributed randomly through the entire audible spectrum.


Do you remember this?) I think it's perfect example of using synthesizer in old game ;) It was created by NIKITA in 1995.

If you're having problems viewing Flash player you can download music there.

As you can see the ES2 has three oscillators. In the default preset the 1 is set to a sawtooth wave, 2 and 3 are both set to square waves with the pulse width set to about 2/3, and 3 is also detuned up 10 cents. The pulse width is a type of modulation controlled by an LFO that modulates the width of the square wave. To the right of the wave dials we see a triangle which looks similar to an x/y pad, but is simply a blend ‘knob’ allowing you to mix between the three oscillators.



Filter


A filter is a module that allows only certain frequencies it receives to pass through, and at the same time is a barrier to others. In this way a filter is used to screen, or filter out, unwanted frequencies from the waveform so as to alter the timbre. The filters can be labeled VCF (Voltage Controlled Filter) or DCF (Digitally Controlled Filter) in our synthesizer.





The most common filters are:


1. Lowpass filter: Low frequencies are passed; high frequencies are attenuated.


2. Highpass filter: High frequencies are passed; low frequencies are attenuated.


3. Bandpass filter: Only frequencies within a frequency band are passed.


4. Band Reject filter: Only frequencies within a frequency band are attenuated.


5. Allpass filter: All frequencies in the spectrum are passed, but the phase of the output is modified.



After being filtered, a brilliant-sounding sawtooth wave can become a smooth, warm sound without sharp treble.



The ES2 has 2 filters which can be used parallel to each other or in sequence, the default preset uses a parallel filter. Filter 1 has Drive, Resonance, and Cut parameters. 
With the Cut knob you select the frequency that the filter begins to reduce, 
the Res knob controls how much resonance is added at the cut frequency, 
and the Drive knob acts like a gain stage. 
The five buttons beside these knobs allow you to choose which type of filter you want, the default is set to a high pass filter. Filter 2 is largely the same with a few differences.

The five buttons of Filter 1 are replaced with 4 slope control buttons which allow you to choose the rate at which the cut descends. The FM knob modulates the Filter 2 Cutoff with the Oscillator 1 frequency.



Amplifier


The amplifier is the module that outputs sound to a sound card or a digital file. It amplifies the signal before the output and it does it with the Envelope.



The Amplifier on the ES2 is the smallest portion. The only true parameter of the amplifier section is the Sine Level  knob which acts as a gain stage. The effects section to the right also contains a Volume and Distortion which, although not technically part of the amp, could still produce the desired loudness.



Envelope


The envelope, also known as ADSR, is what controls the way the oscillator ‘plays’ the notes. ADSR stands for:


Attack time – how fast the note hits or swells,


Decay time – how fast the note goes from the full attack level to the sustained level,

Sustain level – the level at which the note is held while the key is still pressed,


Release time – how fast the note fades away after the key is released.


The ES2 has two true envelopes – 2 and 3 – and another – envelope 1 – that has only attack and decay. In the default preset only envelope 2 is used.



LFO


The LFO, or low frequency oscillator, is called as such because it’s frequency is below the human hearing range. The oscillator is used to modulate other aspects of the synthesizer to add a more player-like sound. We can adjust several settings to produce different effects. It’s great if we want to  sweep similar to tremolo, vibrato or wah-wah. It acts below 20Hz and creates a pitch variation. It’s not a creator of sounds itself, it works when is connected with the oscillator or amplifiers.The ES2 has two LFOs, 1 has an EG slider, which determines how fast the LFO fades in, a Rate slider, which determines the rate the LFO modulates at, and a wave shape button, which determines the type of wave the LFO oscillates as. 2 has only a Rate slider and a wave shape button.



I hope this information will be helpful for you. Synthesizer is a powerful instrument, which have own timbre, like any live instrument. And it's perfect opportunity to give your music more color. Try to experiment and find the sound that you need. Synthesizer has a lot of thing which can help you to reach this goal.


Good luck!

Copyright © Roman Shirokinskiy