In preparation for discussing EQ, Matt gives an overview of how frequencies work in practice. Nearly every sound is made up of many "ingredient" frequencies called partials. Depending on the mathematical relationship between these frequencies, these partials may be harmonic or non-harmonic. An oscilloscope and a spectrum analyzer each give clues about the partials in a sound, and the shape of the wave and the recipe of partials define each other.
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- Frequencies interact in interesting ways…when you combine multiple sounds.…Let's look at some of those interactions…and how they relate to mixing music.…Here's a graph of amplitude versus frequency.…It's called a spectrum analyzer.…And it tells us which parts of the frequency spectrum…are at what amplitude.…It's quite different from a waveform graph…or oscilloscope view.…Being able to read both is important.…So, let's compare them with some test signals.…
(musical tones)…Now every sound, no matter how complex,…is made up of ingredients of sine waves…at different amplitudes, frequencies, and timings…or phases constantly coming and going.…
Let's explore how these graphs work…using simple test tones,…then apply that to more complex sounds.…A sine wave, like this…(musical tone)…is just one frequency.…On the oscilloscope, it's a smooth wave.…Exactly like a graph of the mathematical sine function.…On the spectrum analyzer, it's a spike right at 1000 Hz…and nothing anywhere else,…showing the one frequency that's playing.…
The course starts with explanations of what sound really is and how we hear it, including discussions on frequency, amplitude, phase, and psychoacoustics. Matt explores analog audio signal path, explaining connections, gain staging, and metering. Next, he brings the audio signal into the digital domain, discussing analog to digital conversion, digital gain staging, file formats and compression, and dither.
Then the course digs into digital audio workstations (DAWs), explaining the concepts and misconceptions involved in digital recording systems. Matt describes how memory, CPU speed, and storage affect your DAW's performance, as well as how to manage computer resources and understand the plethora of file formats associated with digital recording. He follows with an overview of MIDI: how to generate, store, process, and communicate MIDI data. He wraps up with the audio processors that are often used for mixing in a DAW—including EQ, compressors, reverb, delay, and many others.
- What is sound?
- The three domains of sound: acoustic, analog, and digital
- The analog vs. digital signal paths
- Converting analog audio to digital
- Digital formats and data compression
- Understanding the five types of DAWs
- Recording performances with MIDI
- Mixing and processing audio with EQ, compression, and other effects