PATCHES N PATHWAYS PART 3/3 EQ CHART/AMPLIFIER/MODULATORS/ENVELOPE GENERATOR
PATCHES N PATHWAYS PART 3/3 EQ CHART/AMPLIFIER/MODULATORS/ENVELOPE GENERATOR
TRANSCRIPT:
EQ CHART
Florence- So we want to show you all a EQ Chart which may put frequencies and using filters in context. Say in a recording sense or if you’re playing with multiple different instruments. So different instruments sounds they all occupy different spaces on frequency range. So you have really low frequencies, starting with things like bass, some drums, going all the way up to the high end with organ, violin, some strings that kind of stuff. So they exist in different frequency ranges and we want to be able to operate them so we can hear them better. And the use of filters is so that you can cut out certain frequencies and have only certain ones be present. You can have others only take up a certain amount of space and therefore everything has its own place and can be heard kinda equally.
EQ Part Two
Chris- Ok, so just like the last image we’ll kinda use this image to imagine or think about frequencies and sound and kind of, what are we doing when we’re accentuating or cutting some of these frequencies? We’ll start at the left side of this chart and we’ll start kinda on the bottom but you can think of the bottom and top as kinda the same thing, the flip side of each other. If we start on the left side we are looking at sub-frequencies. These are frequencies that you cant really hear but you can feel them. You know, the frequencies of a car passing by that you can feel or when bass hit the note and you can feel that but you cant hear it, thats the sub-frequencies. Kinda moving up, through you know, we go into this kind of rumbly area, this kind of area that people describe as “mud”. As we move into the mid-range or warmth or thick kinda area, and as we get towards some of the higher frequencies- these are frequencies that we might describe as being “crisp” or adding sheen, or sizzle or even kind of adding a characteristic of harshness to our sound. And its really helpful we think to have this kind of image in your head as you're using a synthesizer and as you’re playing music in general because you can- using this, really shape your sound, really get the sound to sound exactly how you want and get it to mesh with other instruments and other sounds that you are playing with. Because as we started and kinda talked about with noise, you don't want to have all kinda of frequencies happening at the same time. You actually want to have frequencies separated in a way that you can actually hear them and enjoy them.
Amplifier
Florence- So the last step of the synthesizer pathway that we have is the amplifier. So the oscillators, and the filters, they're doing a great job producing the sound and shaping the sound, now we need to actually amplify the sound. And so you put it through the amplifier which is controlling the volume so that we can hear it.
Modulators
Chris- Ok so we just covered the three most common and basic components of the synthesizer but we have other components to actually allow us to make even more complex sounds. And those are called Modulators. And modulators basically, they don't create any sounds or really actually themselves do anything to the sound. What they do is, they alter the functions of any of the three components that we just mentioned. So you can modulate the characteristics of the oscillator, you can modulate the characteristics of the filter, and you can modulate the characteristics of the amplifier. And we’re going to discuss the tools that you would do that with.
Envelope Generator
Florence- So one of the most common modulators you’ll see on a synth is called the envelope generator. And the envelope generator allows us to shape the sound from the point from which the key is pressed from the point to which the key is released, and what kinds of sounds that’s going to take on. The different components of the envelope generator are known as ADSR and you can see on this ADSR graph you have Attack, Decay, Sustain and Release.
Chris- The envelope generator has four characteristics that you can alter to shape your sound. The first characteristic we’ll talk about is Attack. Attack sets how long does it take for the sound to hit its loudest level once you hit the key.
Decay. Decay sets how long does it take for your sound to die down to the level it will sustain at for as long as you hold the key.
Sustain refers to the level that while you're holding the key that the note will actually hold for most of the time that it is held .
Release controls how long the sound stays around after you’ve released the key.
Envelope Shapes
Florence- So we have common instrument envelope shapes here on this diagram. We have a piano, strings, organ, flute and percussion- and you can see that with the piano you’re getting an immediate attack when you hit the hammer with the string. Then the sound pretty much doesn't sustain and it dies away.
With the strings you’re getting a slow attack and then a sustain as you continue bowing. And then once you stop bowing and you release the sound disappears. With an organ you’re getting an immediate attack and high sustain as you play the key through and then when you release, it barely stays in the air. With the flute you're getting a slower attack because you're taking a breath which then decays to the sustain level as you're breathing through the instrument and then when it releases, the sound lingers for a bit in the air. Lastly with the percussion sound, its going to be an immediate attack, no sustain and no release as the sound is just a single hit.
LFO
Chris- The Low Frequency Oscillator is a modulator that creates an oscillating signal that is lower than the audio range. We use this low frequency signal to modulate the characteristics of any of the other components of the synthesizer. Using the LFO, or low frequency oscillator, we can make the filter move on its own, following the LFO. We can make the amplifier, or the volume, move on its own, making a tremolo affect or we can use the LFO on an oscillator pitch.