Digital Audio Basics

DIGITAL AUDIO BASICS & BEYOND

Let's keep it simple. We could really dive in deep with understanding every facet of digital audio, and if you want to do that, there are some really great books and in-depth articles regarding digital audio on the web. I'm not going to re-invent the wheel so to speak, but I can wade through all of the ridiculousness and get you the right information so that you'll have a basic grasp of digital audio.

For starters, check out these two videos:

So, how does this realistically relate to what you do as a live sound (or recording) engineer? I can say with a great deal of certainty, that you use the above process every time you step into that booth. Do you record the message every service on a CD recorder, MP3 recorder, or DAW? Then digital audio is involved. Even if you have an analog console, and still record on tape (who does that nowadays?), if you use an effects processor for reverb or other effects, then you will have an analog signal being converted to a digital signal, and then back to analog again. Most digital devices have a converter involved. The natural world thus far (and for years to come) is for the most part, an analog world. Just about any modern technology you use day to day, will have some type of digital conversion process involved. For Example: When audio comes out of the digital device you are listening to, for it to be translated to actual speakers or headphones, it has to be converted from digital to analog.

There are 2 different types of converters involved in this process. There is an ADC (analog to digital converter), and an DAC (digital to analog converter). Most devices for live sound that has any digital component in it, will have an analog to digital converter on the input, and then the signal is processed, and then back out through a digital to analog coverter (it's a little more complicated than this, but you get the idea).

This very basic diagram shows the process in which ADC and DAC's are involved in digital devices, like an effects processor or a digital mixing console

Here are some examples of devices that use A/D and/or D/A conversion:

A CD Player/Recorder will have a very basic set of A/D & D/A converters a.k.a. ADC and DAC.

Mytek Stereo ADC (Analog to Digital Converter)

8 Channel Focusrite OctoPre Recording Interface. 8 Channels of ADC's and 8 Channels of DAC's

A DiGiCo SD7 Digital Mixing Console

The DiGiCo SD-Rack Madi POD will handle 56 Channels of Analog to Digital & Digital to Analog Conversions. This unit is used to run audio to and from their SD Series Digital Mixing Consoles. BTW - Notice the redundant power supplies...Very Niiiice.

Digital Audio Connector Types

If you are in audio long enough, you will come across these digital connectors. It will be very important for you to know what they are, how to use them, and what they can accomplish.

Here they are in no particular order ( click on each for a thorough description of what each one is for ):

ADAT Lightpipe - 8 Channels of Audio: Toslink Connector

S/PDIF - 2 different types of connectors for S/PDIF: RCA or Toslink

Firewire - 800 on left & 400 on right.

AES/BEU - Yes it uses an XLR connector, but carries digital information

Thunderbolt

USB

MADI - Can use Fiber Optic or BNC connectors

Dante - Essentially an RJ-45 connector in a robust housing

If at any time you are wondering what a particular technical term may mean on this site, please feel
free to check out this audio glossary!