Quote:
Originally posted by Equinox
yeah, i've made a couple recently, but it's far from being IDM, you can ask Horakhti about that one... wish I had more knowledge in synthesis, I'm just too lazy to learn
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Subtractive synthesis is really easy to get to grips with.
(your usual 2 oscillators, an LFO or 2, A filter and a couple of ADSR's)
oscillators
You have your oscillators which generate your tone, generally these are switchable between Sine (a soft sound) Triangle (a slightly harsher sound) Sawtooth (more nasal) and Square (harsh)
The other switches you get are usually 32' 16' 8' 4' 2' 1' these determine the pitch of the oscillators (usually based at 8 or 16) to put this in laymans terms 16 is an octave above 32, 8 is an octave above 16, 4 is an octave above 8 etc...
We also have a detune switch which means you can make the oscilators out of tune. Why do you want to do this? well, if you very slightly detune it, you get that fat trance type sound (sick) or you can detune it more than that and have a fifth on every note etc....
So what do we have at the moment? A blart or a squeak with no tonal characteristics...
So we then put it through a filter....
filters
A filter removes part of the sound, there are various types of filter..
Lowpass
The most common type is Low pass filter. This allows only frequencies below the cutoff through.
Highpass
This allows only frequencies above the cutoff frequency to go through
Bandpass
This allows only the frequency selected through
Band Reject
This allows all frequencies through but the selected.
You also have something called resonance. This causes the frequency you've selected to be increased, so on a low pass you would have all the frequencies below, none of the frequencies above and the frequencies at the cutoff would be increased by however much you turned the resonance up.
So with a low pass, if you took the slider down from the top, the sound would appear to get bassier and the high end would disappear. With a high pass, if you took the slider from the bottom to the top, the bass would disappear and the sound would appear tinnier.
OK, after the filter stage, we have a blart with either less top, or bottom and a bit of a squeak (if the resonance is up.
But at the moment there is no life in the sound so we need things to modulate it...
modulators
There are two main types of modulators, LFO's and ADSR envelopes. Let's take LFO's first...
LFOs
LFO stand for low frequency oscillator, called so because it's usually set to a pitch that is below human hearing (<20Hz or cycles per second) these are useful for altering what you've already got.
These also have the option of switching between different waveforms, but what these do is alter the way it changes the sound, so if you take a picture of a sine wave and set the LFO to alter the volume...
What will happen is the volume will wobble smoothly like the picture, but if you use a sawtooth wave...
then the volume will rise and sharply go down...
The speed of this depends on the speed of the lfo...
The LFO can be set to alter pitch, volume or frequency cutoff (even more things on some synths) so it can change the sound quite a bit.
ADSR envelopes
ADSR stands for Attack, Decay Sustain, Release.
Attack: This means how long it takes to get to the top level
Decay: how long it takes to get to the sustain level from the top level.
Sustain: The level it sustains the note at after the decay has finished
Release: How long it takes the note to decay after the note has finished.
This is generally used to alter volume and filter cutoff.
So if we take the idea of volume, then for a big fady pad, you'd set a long attack, so it took a while to build up, you don't want the volume to go down from top level, so you set the sustain to the top and don't have to worry about the delay, and set a long release so it will fade into the next note.
For a spiky EBM style bass you'd have a fast attack, or pretty much no attack, a fairly quick decay, and a medium sustain and pretty much no release, for that quick punch.
If you get the idea of what it does with volume, then imagine that with a cutoff frequency and you've got it...
Well, that is pretty much subtractive (normal analogue) synthesis in a nutshell..
No, I am NOT going to go into FM, I'll be here for a week!!!!
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