Re: Music Theory
Posted: Sat Nov 17, 2012 8:53 pm
The pleasures mine bro, no worries, glad I could help 
I'd like to explain a little more because I sort of skimmed over some things.
When I said
Envelopes and LFOs are collectively known as modulators because they are a group of parameters used to change something over time. There are different categories of parameters on any given synth. Modulators are one type, which I've described. Oscillators are another, which produce the actual sound. They send the signal to the speaker driver, instructing it on how it should move in and out. The speed of the oscillation defines it's pitch and the shape of the wave programmed in to the oscillator defines the nature of how the speaker driver moves. A sine wave for example moves the speaker driver in a smooth manner, translating in to a single fundamental tone with no harmonics, it's pitch will be defined by the frequency of oscillation playing an A above middle C for example will instruct the oscillator to modulate the speaker driver at 440Hz as that is the frequency we have decided is the note A within the octave of middle C, this is because of how we have set frequencies into a system of harmonic degrees known as the chromatic scale, every note corresponds to a frequency, 440Hz being the A above middle C.
Anyway Digressions aside back to wave types.Using a saw wave shape on the oscillator makes the speaker driver push out then snap back quickly, this fast movement creates a very sharp preasure change, psychoacoustically it translates in to experiencing a much higher frequency preasure change for that small moment, which we experience as a higher tone overlaying the fundamental wave (that defines the pitch/note of the sound). In the case of a saw wave, it 'sounds' a lot brighter because of these periodic smaller/quicker/higher waves overlaying the fundamental.
What I have been describing (modulators and oscillators) are different parameters. An oscillator creates the sound. A Modulator changes something over time. You can apply modulators to different parameters on a synth inorder to shape the nature of the sound.
The Amplitude Envelope controls will alow you to shape just that. Adding a filter to the sound and applying an enelope to that filter will alow you to change the timbre of the sound over time. Applying an LFO to the tuning of an oscillator (oscillator pitch tuning will be available on pretty much all synths). Will allow you to change the pitch of the note, the frequency of the LFO will define how quickly the pitch modulates. Pitch modulation is a very common technique used in instrumental playing all the time, it is known as 'vibrato'. So creating a vibrato effect in synthesis is essentially applying an LFO modulation to the oscillators tuning parameter.
Another thing I noticed you seemed a little confused about is when people mentioned frequencies. Understanding the frequency spectruk is one of the most fundamentally important aspects of music production. There will be specific reasons people mention applying some kind of process to a certain frequency range, but this will always be dependant on the individual circumstance, so the only thing I can do here is link you to this frequency chart and advise you also browse the sound on sound website looking for articles relating to the frequency spectrum. This is a good one I found with a quick google search.
I can't really think of anything else at the moment but I hope you've picked up enough to begin messing with synthesis. Lastly, understand that it will take you a really long time to get to a point you're happy with, so don't try and make synth patches when in the context of a song, instead do a lot of self teaching and simple exploration of synthesis in general, get a feel for it's nature and different types of synthesis, along the way the terminology will become second nature.
I'd like to explain a little more because I sort of skimmed over some things.
When I said
It wasn't entirely true. What I described is simply the altering of a sounds timbre. Modulation as I described is "to change something over time". But using a filter doesn't necessarily have to involve changing that filter over time. You can use a 'low pass' filter to reduce the amplitude of a sounds higher harmonics (as it allows the low frequency content to pass - a low pass filter).Turnipish Thoughts wrote: Which in synthesis, a filter can be used to alter, that is, it can be applied to reduce or increase certain harmonics present within the tone of a sound. This is known as modulation.
Envelopes and LFOs are collectively known as modulators because they are a group of parameters used to change something over time. There are different categories of parameters on any given synth. Modulators are one type, which I've described. Oscillators are another, which produce the actual sound. They send the signal to the speaker driver, instructing it on how it should move in and out. The speed of the oscillation defines it's pitch and the shape of the wave programmed in to the oscillator defines the nature of how the speaker driver moves. A sine wave for example moves the speaker driver in a smooth manner, translating in to a single fundamental tone with no harmonics, it's pitch will be defined by the frequency of oscillation playing an A above middle C for example will instruct the oscillator to modulate the speaker driver at 440Hz as that is the frequency we have decided is the note A within the octave of middle C, this is because of how we have set frequencies into a system of harmonic degrees known as the chromatic scale, every note corresponds to a frequency, 440Hz being the A above middle C.
Anyway Digressions aside back to wave types.Using a saw wave shape on the oscillator makes the speaker driver push out then snap back quickly, this fast movement creates a very sharp preasure change, psychoacoustically it translates in to experiencing a much higher frequency preasure change for that small moment, which we experience as a higher tone overlaying the fundamental wave (that defines the pitch/note of the sound). In the case of a saw wave, it 'sounds' a lot brighter because of these periodic smaller/quicker/higher waves overlaying the fundamental.
What I have been describing (modulators and oscillators) are different parameters. An oscillator creates the sound. A Modulator changes something over time. You can apply modulators to different parameters on a synth inorder to shape the nature of the sound.
The Amplitude Envelope controls will alow you to shape just that. Adding a filter to the sound and applying an enelope to that filter will alow you to change the timbre of the sound over time. Applying an LFO to the tuning of an oscillator (oscillator pitch tuning will be available on pretty much all synths). Will allow you to change the pitch of the note, the frequency of the LFO will define how quickly the pitch modulates. Pitch modulation is a very common technique used in instrumental playing all the time, it is known as 'vibrato'. So creating a vibrato effect in synthesis is essentially applying an LFO modulation to the oscillators tuning parameter.
Another thing I noticed you seemed a little confused about is when people mentioned frequencies. Understanding the frequency spectruk is one of the most fundamentally important aspects of music production. There will be specific reasons people mention applying some kind of process to a certain frequency range, but this will always be dependant on the individual circumstance, so the only thing I can do here is link you to this frequency chart and advise you also browse the sound on sound website looking for articles relating to the frequency spectrum. This is a good one I found with a quick google search.
I can't really think of anything else at the moment but I hope you've picked up enough to begin messing with synthesis. Lastly, understand that it will take you a really long time to get to a point you're happy with, so don't try and make synth patches when in the context of a song, instead do a lot of self teaching and simple exploration of synthesis in general, get a feel for it's nature and different types of synthesis, along the way the terminology will become second nature.
