Matt outlines how sampling works to convert analog audio to digital. The analog-to-digital converter takes measurments of the analog signal at a specific sampling rate such as 44.1kHz. Before the samples are taken, the audio goes through an anti-aliasing filter to remove any frequencies above the Nyquist limit, or half the sampling rate, which could potentially cause aliasing distortion. Then each sample is quantized, or rounded off, to a number whose precision is determined by the bit depth, such as 24 bits per sample.
- To bring sound from the analog domain…into the digital domain, we use a process called Sampling.…Sampling is done by an analog to digital converter…or ADC for short and it means that…we take regular snapshots, that is measurements…of the voltage of the analog signal…and record them as numbers.…Here's a wave showing a few different sample points…where the voltage of the analog signal was measured.…The timing of how often those samples are taken…is called the Sampling Rate or Sampling Frequency.…
Just like any frequency, this is measured in hertz,…the number of times per second.…The two most common sampling rates…in digital audio are 44.1 kilohertz,…that is 44,100 samples per second…and 48 kilohertz or 48,000 samples per second.…The sampling frequency determines…how detailed a representation of the…analog signal will be captured in the digital domain.…Since higher frequency sounds create…more detail in the shape of a sound wave…than low frequencies,…we need to use a higher sampling rate…to capture those sounds.…
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