It's now the end of the third week of "Introduction to Music Production", an online course from Berklee College of Music via Coursera. We have been learning the editing functions of our DAW.
For this, our third assignment, I chose the suggested topic:
• Categories of effects: Teach the effect categories including which plugins go in each category and which property of sound each category relates to.
== Lesson ==
Sound
First, a review of some properties of sound. There are three properties that we often wish to manipulate:
1. Amplitude refers to what we perceive as loudness of a sound. We often want to raise or lower the loudness of one track relative to the others. More technically, though, we want to amplify the signal to a certain level, but not have it exceed another level. We are affecting the dynamics of the sound.
2. Frequency refers to what we perceive as pitch, but it is really far more complex than that. A tone has a series of harmonics, and it is the relative strengths of those harmonics that give a sound its perceived timbre. We can apply filters that affect certain frequencies, that then change the timbre of a sound.
3. Propagation refers to the movement of sound through a medium; through the air, and how it is reflected from surfaces. The time difference of the signal as it enters our two ears allow us to tell which direction a sound is coming from. We also use a sort of unconscious echolocation, so that the time delay properties of the sound tell us how large a room we are in.
In a DAW, these properties are manipulated using plug-in, and are called "effects". An effect can be applied to one track, or tracks can be sent to a common bus, and the effect applied to the bus.
Categories of Effects
Dynamic Effects, also called "Volume Changing" effects.
These are related to amplitude; they automatically control volume based on the material over
time.
Examples are compressors, limiters, expanders and gates.
Generally, this type of effect determines the overall or perceived volume of the track. They make the tracks sound more even, not too loud or too soft.
A Limiter can raise the overall volume of a track (by setting the Limiter threshold low), but the volume never goes over the specified limit, so the track is never so loud that it "clips". If you set the Limit and Threshold too low, you can squish the dynamics. That's one way to make elevator music.
Filter Effects, also called "Sound Shaping" effects
These control the timbre of the sound. If you recall, timbre is the result of the presence of certain overtones or harmonics of the sound. If you change that pattern of overtones, you change the timbre.
Filters change those overtone patterns. EQ filters, such as parametric filters or graphic equalizers, are examples, as are any high- or low-pass filters.
The range of about 4000-6000 Hz is called the "Presence" range. You can bring a voice or instrument forward or pull it back by a slight gain or drop of these frequencies.
Delay Effects, also called "Time-Based" effects.
They add slight delays to the signal, and are thus related to the propagation principle of sound.
Examples are reverbs, delays, choruses, phasers, and flangers.
The cool thing about these effects is that you can create an audio illusion. You see, if someone is playing in a small room, the sound signals come to both of the listener's ears directly and nearly simultaneously. In a large room, the sound echoes a bit. If you apply a bit of delay to a track, it will sound as if the sound is being played in a large room. This illusion is so great that most DAWs have preset effects for "large room", "small room", etc.
A touch of delay can also just make a track sound fuller and richer.
In Reaper, there are over 200 plug-ins that come with the program. Of note are:
ReaComp - a compressor; a type of dynamic effect.
ReaDelay - a delay effect used to make sounds fuller or thinner
ReaEQ - a filter effect that adjusts the frequency spectrum to change timbre
ReaGate - a filter effect that filters out sound when the volume falls below a specified threshold.
ReaPitch - a filter that can raise or lower the pitch of a sound, or of certain harmonic peaks.
ReaVerb - a delay effect that focuses more on actual reverb and echoes
VST stands for Virtual Studio Technology; VST plugin effects are used by a number of DAWs. There are also VST instrument plugins, and VST MIDI effects.
Each effect has a number of parameters that can be set, but most also have presets that can be used.
=== Reflection ===
I found it very helpful to place effects in categories. However, some effects cross the boundaries. For instance, the ReaGate effect really falls into two categories -- it uses a filter to determine whether to apply a dynamic effect. So all is not black and white.
This topic didn't really call for screen shots. I hope this text-version is okay, and is understandable.
Thank you for taking the time to read it.
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