Chapter 4 - Digital Transmission Flashcards
How is digital audio transmitted between devices?
The binary information is transmitted using a square wave in the Megahertz range. The pulses of negative and positive voltage is interpreted as 1’s and 0’s.
What is Jitter?
Jitter is a time based error. The square wave becomes distorted.
What causes jitter?
Caused by varying time delays from component to component in the signal path.
What are the 5 effects of Jitter?
- Increased “grain”
- Instruments losing their sharp edge and focus.
- Apparent loss of level
- Loss of low-level resolution caused by added noise
- Distortion added to the signal
Name the 5 digital audio transmission formats.
- AES/ EBU
- S/PDIF
- MADI
- A-DAT OPTICAL
- Audio Over IP
What is SDIF-2 used for?
Transmitting serial data between certain digital audio systems sold by Sony in the 1980’s. It is outdated.
What does AES/EBU stand for?
Audio Engineering Society / European Broadcast Union.
What is AES/EBU used for?
Used in professional audio. It is used to convey two-channel or monoaural audio over a shielded twisted pair of wires in a balanced configuration via 3 pin XLR cable. Operates by transmitting channel data and information as blocks of 192 bits. Data is transmitted in an A-B-A-B fashion.
What does S/PDIF stand for?
Sony/Phillips Digital interface
What is S/PDIF used for?
Digital audio transmission between consumer devices.
How does S/PDIF work?
Very similar to AES/EBU. It uses unbalanced Phono (RCA) cables instead.
Is S/PDIF balanced or unbalanced?
unbalanced
Is AES/EBU balanced or unbalanced?
Balanced
What does MADI stand for?
Multichannel Audio Digital Interface
What is a MADI cable used for?
Connecting two digital multichannel devices such as a console and tape recorder.
What is the maximum number of channels that MADI supports?
56
What is the data transmission rate of MADI?
100-mega bits/second.
How does Fiber Optic Transmission work?
It operates by propagating photons through a thin optically clear cable that can be made of either purified glass or plastic. The pulses of light on and off represent binary.
What does ADAT stand for?
Alesis Multichannel Optical Digital Interface
How does ADAT work?
The ADAT protocol conveys 8 channels of digital audio serial information along an optical fibre over short distances.
What does AoIP stand for?
Audio Over IP
What is Audio Over IP?
Distribution of digital audio over an IP network. (Internet or LAN)
Name the 4 Digital Data Transmission Formats.
- LAN
- USB
- IEEE 1394 Firewire 400, Firewire 800
- Thunderbolt
What was the main feature of USB 1.0?
Hot swap.
What is USB 1.0 data transfer rate?
12 megabits per second.
What is USB 2.0 data transfer rate?
480 mbps
Which USB protocol does MIDI use?
USB 2.0
What color is USB 3.0
Blue
What is the Data transfer speed of USB 3.0?
5 Gbps
What are the two revisions of IEEE 1394 firewire?
Firewire 400 and firewire 800
What is Firewire?
The industry-standard implementation of Apple’s 1394 digital I/O system.
How many devices can you connect with Firewire without additional hardware?
63
What is the transfer speed of thunderbolt?
10Gbps
