AET 2050 - DAW Production

5. Data Transmission


  1. Describe the advantages of using digital interconnections over analog interconnections.
  2. Identify the two components of a digital interconnect format.
  3. Define word clock, bit clock.
  4. Differentiate between embedded clock and dedicated clock.
  5. Given one or more devices, determine a proper clocking scheme for direct connect, daisy-chain, or star topologies.
  6. Define the relationship between Master and Slave clocking.
  7. Select the appropriate clock sources for devices.

Transmitting Audio Data

Two methods:



Digital Data Transmission Formats in General

Numerous data formats have been devised for digital interfacing.

These formats define such potential variables as:

Components of Digital Audio Transmission

All digital transmission formats must have:

Digital clock

Digital audio transmission requires that the sample timing of each device be synchronized together.

i.e. The device receiving each of the samples per second must know

Do you know when each sample to the left starts and stops?

1) HOW many samples per second are being sent (44.1k, 48k, 96khz etc),

2) How long the samples are (i.e. 16 bits long, 24 bits long, etc)

3) Exactly when each one starts & ends.... a giant stream of 1's & 0's don't mean much if you don't know how to break each down into an audio sample.

If the clocks are not sync'd, errors will manifest:

From a user's point of view, the only difference between analog and digital transmission is that digital requires a timing reference.

The timing reference is a known as the clock - a signal that identifies when a sample of audio is executed.

Types of Clock Signals

Internal clock

Word clock

Bit clock

Other clock sources

Transmission of Clock

Two basic methods of clock signal is transmission:

Embedded clock

Dedicated clock

Is one better?

Clocking Master and Slaves

Digital audio equipment has the capability of determining its clock source - either internal or external.

Absolutely, positively, without a shadow of a doubt, there can be only one clock source, or clock master. All other devices must receive their clock reference from this one master; in essence, they become clock slaves.

One master, all others are slaves to that master.

The master uses an internal reference, and the slaves use an external reference, sourced from the master.


Establishing the Clock Reference

Two pieces of gear


Multiple pieces of gear


Daisy-Chain, or Loop

Word clock with a THRU port


Example connection schemes

Two devices:   

Click here to view proper settings & connection



Three devices:  

A proper connection A and B

With Real Gear