Cabling for Audiovisual Systems

Introduction

This chapter covers the standard AV cables and signal types, performance considerations, environmental considerations, conventions, and best practices for planning, designing, and installing cabling for AV systems.
Cabling for AV Systems consists of three key components:
  • Cable and Signal Types encompasses the cable types utilised for the transmission of AV signals
  • Cable Termination covers the cable end points including connectors, patchbays, cable testing, and adaptors
  • Cable Management outlines the best practices for lacing and looming, cable pathways, mitigating environmental impacts to cable performance, compliance with building regulations, labelling, and colour codes
Integrated AV systems feature a diverse range of inter-connected components transmitting a variety of AV signal types. AV signals are commonly high frequency, high bandwidth and susceptible to electromagnetic interference and crosstalk. The performance of a cable is determined by its intrinsic transmission capability, proximity to other services, and environmental conditions. Any possible degradation to an AV signal performance can be mitigated by intelligent planning and design.
This chapter focuses on low-voltage cabling specific to commercial AV integrated technology. AV cabling includes the following:
  • Any low-voltage wired connection between two devices in an AV system
  • Any low-voltage wired connection between an AV system device and building automation system (lighting, blinds, HVAC, occupancy sensor, et al)
  • Any low-voltage wired connection between an AV system and building fire panel
  • ICT network cabling and infrastructure supporting transmission of AV signals
The following cabling categories are outside the scope of this chapter:
  • Electrical cabling and circuits
  • Lighting cabling and circuits
  • Telephony cabling and infrastructure
  • MATV cabling and distribution infrastructure

Glossary of Terms

Term
Definition
10 / 100 / 1000 / 10G Base-T
Standard terminology used to denote groups of network standards, including Ethernet frame transfer speeds, representing 10 Mbps, 100 Mbps, 1000 Mbps (1Gbps) and 10Gbps bitrates, respectively.
4K UHD 60
Digital video resolution of 3840 × 2160 (8,294,400 pixels) at 60 frames per second (60Hz).
8P8C connector
8 position 8 contact (8P8C) is a modular connector commonly used to terminate twisted pair cabling used for Ethernet, often referred to as RJ45.
Analogue; Analog
An analog signal is in the form of a wave that uses continuous variations in time (e.g., voltage amplitude or frequency variations) to transmit information.
AS
Australian Standard
AV System
A multimedia presentation system for video and audio presentations
AV
Audiovisual (AV) encompasses the integrated devices for managing the routing, processing, and presentation of video and audio content. It may also include associated AV network data streams, user control interfaces, and automation processes.
AWG
American Wire Gauge (AWG) system used for the diameters of round, solid, nonferrous, electrically conducting wire. The cross-sectional area of each gauge is an important factor for determining its current-carrying capacity and resistance to EMI.
Balanced
Balanced connections typically use shielded twisted-pair cable.The two wires form a circuit carrying the audio signal; one wire is in phase with respect to the source signal, the other wire is reversed in polarity.
This means that much of the electromagnetic interference will induce an equal noise voltage in each wire, which may then be identified and removed from the signal.
Bitrate;
Data rate
In computing, and transmission of data streams, bit rate is the number of data bits that are transferred per second
Chroma Subsampling
A type of compression that reduces the color information in a signal in favor of luminance data. This reduces bandwidth without significantly affecting picture quality.
Colour Space: RGB
A particular RGB color space is defined by the three chromaticities of the red, green, and blue additive primaries
RGB can produce any chromaticity that is the triangle defined by those primary colors combined with gamma correction to adjust colour intensity
Colour Space: YCbCr (4:n:n)
YCbCr Is Designated as 4:n:n (Y:Cb:Cr) for digital video signals.
Y(4) is the sampling rate of the Luma (luminance)
Cb:Cr (n:n) is Chroma difference (Blue minus Luma:Red minus Luma)
See Chroma Subsampling
Decibel (dB)
A unit of measurement to express the ratio of one value of a power to another on a logarithmic scale.
It may be used to measure and calculate the following:
Speaker loudness (SPL) reduction at different listening positions:
  • 20 x Log10(Meters away from Speaker) = dB loss
Speaker sensitivity and output loudness:
  • Double Power (W) = 3dB gain
    • Half Power (W) = 3dB loss
  • Signal loss over cable distance:
    • (Refer to cable specifications)
Dual-Link (DVI)
Variant of digital video interface connector (DVI) capable of 7.92Gbps data transfer rate
Dual-Mode / DP++ (DisplayPort)
Compatibility for DisplayPort output interfaces to transmit to a Single-Link DVI, or HDMI input interfaces via a passive adaptor. Limited to 1080p resolution.
Not backwards compatible (HDMI to DisplayPort)
EIA
Electronic Industries Alliance
EMI
Electromagnetic interference (EMI), also called radio-frequency interference (RFI) when in the radio frequency spectrum, is a disturbance generated by an external source that affects an electrical circuit by electromagnetic induction, electrostatic coupling, or conduction. The disturbance may degrade the performance of the circuit or even stop it from functioning.
Full-Duplex
A communications interface may send and receive messages simultaneously via a single cable.
HDCP
High-bandwidth Digital Content Protection (HDCP) is a form of digital copy protection developed by Intel Corporation[1] to prevent copying of digital audio & video content as it travels across connections. Types of connections include DisplayPort (DP), Digital Visual Interface (DVI), and High-Definition Multimedia Interface (HDMI)
HDMI
High-Definition Multimedia Interface (HDMI) is a proprietary audio/video interface for transmitting uncompressed video data and compressed or uncompressed digital audio data from an HDMI-compliant source device, such as a computer or document camera, to a compatible sink device, such as a data projector, flat-panel display or recording device.
HID
Human Interface Device is a peripheral that connects to a computer to allow a user to interact and provide input. Examples include keyboard and mouse
ICT Architecture
Information and communications technology architecture encompasses the computers, servers, phone systems, and network switching and routing for an organisation’s network
IP Address
An Internet Protocol Address (IP Address) is used for network communication between computer devices. The IP address allows a device to be identified on the network
IR
Infrared. In AV systems, IR is typically used for one-way control and automation of third-party controllable devices
LAN
Local Area Network (LAN) is a network of interconnected computers within a building or department
Normal
A normal connection in an audio or video patchbay is a default internal connection between a pair of connectors. The internal connection is interrupted if a patch cable is plugged into the patchbay.
NZS
New Zealand Standard
Ohm (Ω) / Impedance
An ohm is a resistance (impedance) that produces a potential difference of one volt when a current of one ampere is flowing through it. As impedance is increased, the current flow (ampere) is reduced.
Impedance rating may be a characteristic of a cable, or a circuit (resistor / transformer)
RS232;
RS422;
RS485
A telecommunications standard for serial communication and data transmission. In AV systems, typically used for point-to-point two-way control and automation of third-party controllable devices
Shielded / Screened Cable
A cable of one or more insulated conductors enclosed by a common conductive layer. The shield may be composed of braided strands of copper (or other metal, such as aluminium), a non-braided spiral winding of copper tape, or a layer of conducting polymer. Usually this shield is covered with a jacket.
Simplex
Communication may only be transmitted one way via a cable (sender to receiver)
Single-Link (DVI)
Variant of digital video interface connector (DVI) capable of 3.96Gbps data transfer rate
TIA
Telecommunications Industry Association
Unbalanced
Unbalanced audio cable provides a simple pair of conductors for the audio signal to travel on. This normally means that any electromagnetic interference the cable picks up will be induced into the audio signal. This is a common reason for undesirable hum or noise.
Wi-Fi
Wi-Fi is a family of radio technologies that is commonly used for the wireless local area networking (WLAN) of devices which is based around the IEEE 802.11 family of standards.
WLAN
A wireless LAN (WLAN) is a wireless computer network that links two or more devices using wireless communication to form a local area network (LAN) within a limited area such as a home, school, computer laboratory, campus, office building etc.

Key Stakeholders

Below is a list of stakeholders commonly involved in the planning, deployment, and maintenance of an Cabling for AV Systems solution:
  • AV and ICT Managers (design of integrated technology)
  • End Users (functionality, features, and user experience)
  • Facility Management (passive network, cabling, patching infrastructure)
  • Structural Engineer (Penetrations, cable pathways)
  • Architect (AV services plan)

Cabling Standards and Licensing

Building Regulation Compliance

Below are some key considerations for achieving building regulation compliance.
  • Any cables installed within a plenum must be rated for low smoke zero halogen (LSZH)
  • Any building penetrations used for cable pathways must be firestopped to maintain the integrity of the building fire rating
  • The following should be coordinated with the building structural engineer:
  • Any planned chased concrete cable pathways
  • Any planned building penetrations to accommodate cable pathways

Cabler Licensing & Registration (Australia)

In Australia, If cabling is used, or intended to be used, to provide a connection that ultimately leads to a telecommunications carrier's network boundary, that cabling is legally considered "customer cabling" under the Telecommunications Act 1997. In other words, if the AV system is reachable via the internet, the communications cabling in the system, even past the first piece of customer equipment, is customer cabling, and licensing applies. Customer cabling parts and installation work are regulated by the ACMA (Australian Communications and Media Association), a federal government authority. New Zealand does not have any such authority.
Cablers must register with one of the five authorities, in order to perform certified cabling installations, or supervise colleagues to do so. Certifications exist for structured wiring (S), optical fibre (O or OF), coax (C), aerial (A) and underground (U).
Individual cablers can be searched on one of the sites below, if required, but it is best to simply request that certification details be provided as part of a tender submission.
Registration Authority
Website
Australian Cabler Registration Service (ACRS)
TITAB Australia Cabler Registry Services (TITAB)
BISCI Registered Cablers Australia (BRCA)
Australian Security Industry Association Limited (ASIAL)
Fire Protection Association Australia (FPAA)

Manufacturer’s Warranty

As well as being a licensed cabler for the appropriate application, it is also crucial to ensure that the cable install will be warranted by the manufacturer for the
This can be achieved by specifying that the work is carried out by a Certified Installer for a major manufacturer of wiring systems that complies with the latest published AS/NZS 11801 Category 7 specification. Evidence of Certified Installer status shall be presented in the form of a recent letter from the relevant wiring system manufacturer. The manufacturer's system warranty shall be provided for the installed wiring system, the warranty to be valid for a period of not less than 15 years. The customer may nominate a specific brand of wiring system to be used for the work.

Cabling Standards Reference List

Below is a reference list of Australian/New Zealand standards documents pertinent to cabling for AV systems, associated with various applications and environments. Your organisation’s network cabling standards should already be referencing the below as the authority responsible for passive cabling on campus.
Inclusion of your own organisation’s network cabling standards in all works and ensuring AV cable installers are held to the same or higher standards is the minimum recommended approach to ensure cabling is installed to both manufacturer’s requirements and those of the organisation.
Reference
Document Title
AS/CA S008:2010
Requirements for Authorised Cabling Products – Statutory
AS/CA S009:2013
(formerly ACA TS009)
Installation Requirements for Customer Cabling (Wiring Rules) – Statutory
AS/NZS 11801:2019
Information technology - Generic cabling for customer premises General requirements
AS/NZS 3000:2016
SAA Wiring Rules
AS/NZS 3080:2013
Telecommunication Installations – Integrated Telecommunications Cabling System for Commercial Premises
AS/NZS 3084:2003
Telecommunication Installations – Telecommunications Pathways and Space for Commercial Buildings
AS/NZS 3085.1:2003
Telecommunications Installations – Administration of Communications Cabling Systems
AS/NZS 3087.1
Telecommunications Installations – Generic Cabling Systems – Specification for Testing of Balanced Communication Cabling in accordance with Values set out in AS/NZS 3080
AS/NZS ISO/IEC 14763.3
Telecommunications Installations - Implementation and operation of customer premises cabling - Testing of optical fibre cabling
AS/NZS 4703:2007
Electrical wiring in furniture
HB 243
Communications Cabling Manual – Module 1 Australian Regulatory Arrangements
HB 29
Communications Cabling Manual – Module 2
AS 2834
Computer Accommodation
AS 3260
Safety of Information Technology Equipment Including Electrical Business Equipment
AS 3548
Electrical Interference – Limits and Methods of Measurement of Information Technology Equipment
AS/NZS 2211.1
Safety of Laser Products – Equipment Classification Requirements and User’s Guide (EC 60825-1 2001 MOD)
AS/NZS 2211.2
Laser Safety – Safety of Optical Fibre Communication Systems
AS/NZS 2211.10
Safety of Laser Products – Application Guidelines and Explanatory Notes to AS/NZS 2211.1 (EC TR 60825.10 2002 MOD)
AS/NZS 4261.1
Electromagnetic Compatibility – Generic Emission Standard – Residential, Commercial and Light Industry
AS/NZS 2063
Conduits and Fittings for Electrical Installations
AS 3600
Concrete Structures
AS/NZS 2648
Underground Marking Tape
TIA/EIA 606-A
Administration Standard for the Telecommunications Infrastructure of Commercial Buildings
EIA/TIA 862
Building Automation Systems Cabling Standard for Commercial Buildings
EIA-3100
Cabinets and 19” Equipment Frames

Cable Types and Signals

An AV cable may include:
  • any low-voltage wired connection to or from a device in an AV system;
  • any wired connection that transmits video, audio, and/or control messages;
  • ICT network cable connections to devices in an AV system;
An AV signal is defined as:
  • any video, audio, USB data, or control messages transmitted between devices in an AV system;
  • any video images that may be presented to a display or projector;
  • any sound that may be made audible by speakers or headphones;
  • any video or audio that may be recorded by a capture device;
  • any control messages to change the state of a device in an AV system;
  • any control messages to report the current state of a device in an AV system.

Cable Termination

Cable termination for AV cables:
  • is any end point of an AV cable;
  • may be a plug termination to connect an AV cable to an AV equipment interface, patchbay, or junction;
  • may be a socket termination to a connection plate, patchbay, junction box, etc.

Recommendations for Cable Runs & Terminations

General

  • Any cables run in walls, ceilings or floors are presented at both ends on a fixed outlet, with an easily replaceable patch cable used to interface with the device at each end.
  • Point-to-point Category (CAT) cabling generally uses solid-core type cabling for structured runs between field devices, with a fixed outlet at each end, and stranded type, prefabricated patch cabling at each device.
  • All digital video cables and stranded CAT patch cables (e.g. CAT6/CAT6A) should be prefabricated and designed of appropriate length for the signal path.
  • No field terminated USB/digital video cables (e.g. USB-C, HDMI, DVI) should be accepted.
  • All other cables, with the exception of high frequency power cables which must be cut to an electrical length, should be cut to the length dictated by the run.
  • Fixed outlets, terminal blocks, boards, strips or connectors, should be supplied for all cables which interface with racks, cabinets, consoles or equipment modules, as is appropriate for the application.
  • Cables should be of the correct type and manufacturer outlined in the drawings and specifications unless equivalents are approved in writing. If a specific cable type is required for a particular product, it must be identified by the AV consultant or contractor and included in the bill of materials of a project.
  • All use of data cabling whether used for network data or AV signal transmission must comply with the organisation’s data cabling standards for quality, installation and termination. To be accepted the installed cabling must pass the organisation’s approved testing process.
Audio cabling
  • Proper circuit polarity and loud speaker wiring polarity should be observed at all times.
  • No cables should be wired with a polarity reversal between connectors at either end.
  • All circuits should be balanced and floating, except as noted in manufacturer specifications. All system wire, except spare wire, after being cut and stripped, should have the wire strands twisted back to their original lay and be terminated by approved soldered or mechanical means. No bare wire ends should be accepted.
  • Heat shrink type tubing should be used to insulate and dress the ends of all wire and cables including a separate tube for the ground or drain wire.
  • All solder connections should be made with rosin-core solder. Temperature controlled soldering irons rated at least 40 watts shall be used for all soldering work. All mechanical connections should be made with approved crimp plugs of the correct size and type for the connection. Wire nuts are not permitted. Each connector should be attached with the proper size controlled-duty-cycle ratcheting crimp tool which has been approved by the manufacturer of the connectors.
  • XLR patch panels and connectors should be wired as follows (using the “pin 2 hot” convention):
Connector
Signal
Pin#2
Hot or Positive
Pin #3
Cold or Negative
Pin #1
Ground or common

Factory-Made Connectors

Factory-made (molded, pre-made, or pre-molded) connectors can have the following features which may be beneficial to an installed system:
  • Factory-made with reliable build quality
  • Terminations can be environmentally sealed up to IP68 rating
  • Reduces time spent terminating cables
  • Cable length (must be) determined prior to installation and cable rough-in.
Factory-made cables and connectors are typically used in the following applications, however their use can be extended to any signal cable, provided it meets organisational cabling requirements.
Connector Type
Plug, Socket, Both
Typical Applications
HDMI
Both
All
DVI
Both
All
DisplayPort
Both
All
USB
Both
All
Unshielded 8P8C RJ45
Plug
Fly Leads, Patch Cables
Shielded 8P8C RJ45
Plug
Fly Leads, Patch Cables
TOSLINK (JIS F05)
Both
All
Fibre Connectors
(LC, SC, PC, FC, etc.)
Both
All
HD15 (VGA)
Plug
Fly Leads, Patch Cables
3.5mm TS
3.5mm TRS
3.5mm TRRS
Plug
Fly Leads, Patch Cables
6.5mm TS
6.5mm TRS
Plug
Fly Leads, Patch Cables
RCA
Plug
S/PDIF, Fly Leads, Patch Cables
XLR3
(EIA RS-297-A)
Plug
Patch Cables

Hand-Terminated Connectors

Hand-terminated connectors have the following features, which may in some applications have benefits, but can also introduce elements of risk to the system:
  • Cable conductors are soldered or crimped to a plug or socket connector
  • Heat shrink may be used to insulate exposed pins and conductors
  • Stripping the cable jacket may make the cable susceptible to damage from bending or pulling (heat shrink may be used to improve the robustness of the cable)
  • Flexibility to use connectors and shells that match installation conditions and requirements
  • Cable length may be measured and determined on-site
Hand-terminated cables and connectors are typically used for the following applications:
Connector Type
(Applicable Standard)
Plug, Socket, Both
Typical Applications
Unshielded 8P8C RJ45
(TIA/EIA-568B)
Socket
Plenum, Riser
Shielded 8P8C RJ45
(TIA/EIA-568B.2)
Socket
Plenum, Riser
Fibre Connectors
(TIA/EIA-568B.3)
Both
All
HD15 (VGA)
Plug
Fly Leads, Patch Cables
3.5mm TS
3.5mm TRS
3.5mm TRRS
Plug
Fly Leads, Patch Cables
6.5mm TS
6.5mm TRS
Plug
Fly Leads, Patch Cables
XLR3
(EIA RS-297-A)
Both
All
RCA
Both
Fly Leads, Patch Cables
Euroblock / Phoenix
Both
All
D-sub 9 (DE9, DB9)
Both
All
D-sub 25 (DE25, DB25)
Both
All
3, 4, 5, 6 Pin Mini-Din
Both
All
BNC
Both
All
UHF RF Antenna
Both
All
SpeakON
Both
Speaker Connections, Amplifier Connections
Spring Terminal
Bare copper into terminal
Speaker Connections, Amplifier Connections
Screw Terminal
Bare copper into terminal
Speaker Connections, Amplifier Connections
Banana Connector
Plug
Speaker Connections, Amplifier Connections
MOLEX
Plug
Low Voltage Power Connections

AV Signal Patchbays

AV signal patchbays are commonplace in recording and broadcast studios, as well as event spaces, but may be appropriate in a number of applications.
Conventions for AV signal patchbay designs:
  • AV signal typically flows from top row of connectors to bottom row of connectors
  • Top row of connectors wired to AV device output interfaces
  • Bottom row of connectors wired to AV device input interfaces
  • The front panel of the patchbay must be labelled above each connector to identify the connector reference number, function and/or associated AV device input/output
  • Use robust connectors to minimise risk of damaging cables and/or connectors through frequent plugging and unplugging of patch cables
  • Typically use 19” rack-mounted panel or wall-box

Normal Connections

A normal connection in an audio or video patchbay is a default internal connection between a pair of connectors. The internal connection is interrupted if a patch cable is plugged into the patchbay.
Normalled Circuit
Connector Function
Non-Normal Patchbay
  • No internal connection between top and bottom connector.
  • Patch cables required to make connections between top and bottom rows of connectors.
  • Typically used if connectors are not associated.
Half-Normal Patchbay
  • Default internal connection between top and bottom connectors.
  • Patch cable plugged into the top row (output) does not interrupt the circuit. Signal split to internal connection and patched connection.
  • Patch cable plugged into bottom row (input) breaks the internal connection to top row.
  • Typically used to split the top row signal to a monitor or headphone while maintaining the internal default connection.
Normal (Full-Normal) Patchbay
  • Default internal connection between top and bottom connectors.
  • Patch cable plugged into top or bottom rows breaks the internal connection.
  • Typically used to bypass default internal connections to make a new signal path with patch cables.

Ethernet Patchbays

Ethernet patchbays are commonplace in communications rooms, AV racks and lectern designs. They are a recommended solution wherever a large number of communications cables are co-located, as they allow organisation in a relatively small footprint, and are often called for by organisational network cabling standards.
Conventions for network patchbay designs:
  • Use colour-coded cables and/or patchbay labels to identify each cable by function, network traffic type, or subnet
  • The front panel of the patchbay must be labelled above each connector to identify the connector reference number, function and/or associated AV device input/output
  • Use robust connectors to minimise risk of damaging cables and/or connectors through frequent plugging and unplugging of patch cables
  • Typically use 19” rack-mounted panels
  • Typically a cable strain-relief bar is installed above or below the patch panel
  • Where twisted-pair cabling of differing categories or brands are combined on a single patch-bay it is best to ensure installers have consulted with all manufacturers involved to validate compatibility with patch panels, cables, outlets and labelling systems
    • Requesting a sample for approval is recommended, as well as confirmation of manufacturers warranty for all parts of the installation.

Standards Compliance

Network patchbays should comply with the following standards as a minimum to ensure the installation can support current and future technologies and signals:
  • ANSI/TIA-568-C.2
  • ISO/IEC 11801 2nd Edition
  • IEC 60603-7
  • IEC 60603-7-51
  • IEEE 802.3an
  • IEEE 802.3af (PoE)
  • IEEE 802.3at (PoE+)
  • IEEE 802.3bt (PoE++)
  • ANSI/TIA-1096-A

Cable Testing

To verify the integrity of AV cables once installed, each signal path/cable type should be tested using the following specialised equipment:
Testing Equipment
(AV Signal)
Typical Features
Tests
Digital Video Cable Tester
(HDMI / DVI / DisplayPort)
  • Test Pattern Generator
  • 4K60 (4096x2160 60Hz)
  • RGB/YCbCr 4:4:4 (30 bit)
  • HDCP 2.2, 1.4, Off
  • EDID
  • Audio tone generator
  • 16-channel Audio send
  • Up to 18Gbps integrity
  • 19-Pin continuity
  • Shorted pins
  • Open pins
  • Audio send / receive
SMPTE Coax Cable Tester
(3G/HD/SD-SDI)
  • Test Pattern Generator
  • Waveform monitor
  • Audio tone generator
  • 16-channel Audio send
  • Up to 1002 MHz frequency
  • Return loss
  • Cable continuity
  • Shorted pins
  • Open pins
  • Audio
Category 6A Cable Tester
(10GBase-T / HD-Base-T)
  • Pass / fail indicator
  • Report generator
  • Compatible with all current network cabling standards
  • Up to 10Gbps integrity
  • Crosstalk
  • Return loss
  • Shield faults
  • Cable continuity
  • Shorted pins
  • Open pins
Audio Cable Tester
(Balanced/Unbalanced Mic/Line Audio)
  • Pass / fail indicator
  • Cable continuity
  • Shorted pins
  • Open pins

Adaptors/Converters

Converting one signal to another may require an active or passive adaptor, depending on the source and the destination AV signals.
Whilst adaptors are useful for converting one AV signal to another, their use should be minimised wherever practical to simplify system designs, reduce points of failure and increase system robustness.
Below is a table of common AV signal conversions, adaptor required, and AV signals passed or lost in the conversion (where they originally may have existed). Note that manufacturer solutions may differ, so the specification should always be checked.

Video Signals

Original
AV Signal
Converted
AV Signal
Active or Passive Adaptor
Passed Through
AV Signals
Lost
AV Signals
HDMI / DVI-D / DisplayPort
HDBase-T
Active
(Transmitter)
All
None
HDBase-T
HDMI / DVI-D / DisplayPort
Active
(Receiver)
All
None
HDMI / DVI-D / DisplayPort
AV over IP
Active
(Encoder)
All
None
AV over IP
HDMI / DVI-D / DisplayPort
Active
(Decoder)
All
None
HDMI
DisplayPort
(Dual -Mode DP++)
Active
Video, Audio, HDCP, EDID
Ethernet, CEC
HDMI
DVI-I / DVI-D
(Single-Link)
Passive
Video (1080p), HDCP, EDID
Video Resolution, Audio, Ethernet, CEC
HDMI
Stereo Line Level Audio
Active
(De-Embedder)
Audio
Video, HDCP, EDID, Ethernet, CEC
HDMI
12G / 6G / 3G-SDI
Active
Video, Audio
HDCP, EDID, Ethernet, CEC
DisplayPort
(DP)
HDMI
Active
Video, Audio, HDCP, EDID
USB
DisplayPort
(Dual -Mode DP++)
HDMI
Passive
Video, Audio, HDCP, EDID
USB
DVI-I / DVI-D
(Single-Link)
HDMI
Passive
Video (1080p), HDCP, EDID
None
12G / 6G / 3G-SDI
HDMI
Active
Video; Audio
None
VGA
HDMI
Active
Video
None
VGA
RGBHV
(Component)
Passive
Video
None
RGBHV
(Component)
VGA
Passive
Video
None
DVI-A / DVI-I
VGA
Passive
Video
None
VGA
DVI-A / DVI-I
Passive
Video
None

Audio Signals

Original
AV Signal
Converted
AV Signal
Active or Passive Adaptor
Passed Through
AV Signals
Lost
AV Signals
HDMI
Stereo Line Level Audio
Active
(De-Embedder)
Analogue Audio
Videog Digital Audio, HDCP, EDID, Ethernet, CEC
HDMI
S/PDIF
Active
(De-Embedder)
Digital Audio
Video, HDCP, EDID, Ethernet, CEC
Stereo Line Level Audio
Mono Line Level Audio
Passive
(Summing Circuit)
Audio
None
Mono Line Level Audio
Split Line Level Audio
Active
(Audio DA)
Audio
None
Line Level Audio
Mic Level Audio
Passive
(Attenuation Circuit)
Audio
None
Mic Level Audio
Line Level Audio
Active
(Pre-amp)
Audio
None
Analogue Audio
(Mic / Line)
Digital Audio
(AES3)
Active
(D/A Converter, DAC)
Audio
None
Digital Audio
(AES3)
Analogue Audio
(Mic / Line)
Active
(A/D Converter, ADC)
Audio
None
Balanced Audio
Unbalanced Audio
Passive
Audio
None
Unbalanced Audio
Balanced Audio
Passive or Active
(Balun, DI unit)
Audio
None

Cable Management

Cable management for AV cables includes:
  • planning for cable pathways, transmission lengths, penetrations, risers, and installation environments for AV cables;
  • conduits, cable trays, lacing, looming, and other accessories required for neat and tidy installation of AV cables;
  • planning for mitigating electromagnetic interference (EMI), environmental hazards, and other factors that may compromise AV signal integrity;
  • planning for cable bend radii, and minimising potential damage to AV cables;
  • a methodology for labelling and identifying AV cables.

Cable Pathways

Consider the following when planning the cable pathways for AV cables:

General

  • Installed plenum cables should be fastened at regular intervals so there are no sagging segments of cable
  • Installed plenum cables must not rest along the inside of the ceiling cavity (eg. on top of ceiling tiles), bottom of raised access floors (computer floor), or touching the finished floor surface
  • Cables, and cable pathways (with the exception of fly leads) should not be visible to the users of the AV system. Install cables in the following spaces to conceal AV cables from view:
    • inside wall, ceiling, floor cavities;
    • within conduit, mounting poles;
    • within sunken cable raceway / cable track;
      • NOTE: above-floor solutions, including “track” and “floor gnomes” often create substantial WHS hazards and should be avoided.
    • behind flat panel displays;
    • above projectors;
  • Cables typically follow an orthogonal path:
    • inside Walls: Vertical only;
    • ceiling / floor surfaces: parallel, or at right angles to ceiling structure.
  • Intersecting cable paths should do so perpendicularly (at right angles)
  • Unshielded / unbalanced cables should be at least 600mm from other services to reduce EMI impact to signals
  • Any excess cable length should not be coiled, instead being dressed and routed horizontally and vertically whilst considering cable bend radius. and fastened near to one end of the cable taking care not to exceed the specified lowest bend radius threshold of the cable
  • Typical operating temperatures are -20 to +60 degrees Celsius. Ensure cables are not exposed to any sources of extreme heat or extreme cold

Cable Bend Radius

  • Any bend in an AV cable must be:
    • Greater than the minimum bend radius as specified by the cable manufacturer; or
      Greater than 8 x the cable diameter
  • For all cable bends, the AV cable should be fastened before and after the bend
  • Any bend in an AV cable that is less than the specified minimum bend radius is at risk of damage or degraded signal quality

Plenum - Catenary Wire

  • Typically installed to support cables run through ceiling cavities
  • Catenary wire is typically used to support several cables
  • Catenary wire should be installed so it does not touch or drape over other services or cables
  • Cables may be fastened to the catenary wire to reduce cable sag
  • All cables fastened to a catenary wire are effectively bundled together and may be susceptible to crosstalk or EMI

Plenum - Cable Trays

  • Typically installed to support cables run through ceiling cavities or raised access floors
  • Cable tray is typically used as cable support for any number of cables for various functions
  • Cables may be fastened to a “lane” of the cable tray to segregate cable and signal types along the length of the cable tray

Conduits

  • Typically installed to support cables run through wall cavities, chased concrete, building penetrations, or outdoor cable paths
  • Conduit material may provide added shielding from EMI as:
    • any PVC conduits provide a dielectric (non-conductive) barrier;
    • any metallic conduits should be earthed to produce shielding from EMI for cables within.
  • Conduit diameter should allow for:
    • the total diameter of all cables to be run;
    • the size of the connectors that will pass through the conduit (e.g. HDMI factory-made cables);
    • spare capacity should allow for reduced cable strain, and future cables.
  • Any bend in a conduit should not force any cables within to exceed the specified lowest bend radius tolerance
  • Any bend in a conduit should allow pass through of a cable connectors (eg HDMI factory-made cables)
  • A draw wire should be included for each conduit
Risers
  • Typically used for inter-floor structured cable pathways
  • Smaller versions are often constructed to pass cables between floor and ceiling positions where wall rough-in is not possible or cost prohibitive.
  • Often include other services (electrical, communications) which must be considered when running cables in risers.
Chased Floor
  • Typically a method to create a cable pathway from a floor box to the base of a wall
  • Chased channels should be wide and deep enough to fit the number of conduits required for the system design, as well as leave spare capacity for future, including conduit and draw wire(s).
  • Other services (electrical, communications) must be considered when coordinating slab chases.
Floor Slab Penetrations
  • Typically a method to create a cable pathway between floors when a chased cable pathway is not feasible.
  • Coordination with building works and slab structure must be considered as penetrations can be difficult and expensive once carpet has already been laid.
  • Slab penetrations are simpler to achieve when not immediately next to a wall, though still possible with the right contractor and equipment.

Electromagnetic Interference and Crosstalk

Electromagnetic interference and crosstalk can negatively affect the quality and transmission efficiency of AV cables. The AV designer must be aware of common sources of EMI, and ways to mitigate its effects on an AV system.
Note: EMI has no effect on fibre optic cables

Sources of Electromagnetic Interference:

  • Electrical power cabling
  • Electrical transformers
  • Radio frequency (RF) sources
  • Large motors and generators
  • Induction heaters
  • X-Ray Equipment
  • Photocopy equipment
  • Industrial ovens and microwave ovens
  • Fridges and freezers
Most of these sources will only produce EMI when powered up and actively engaged, so EMI can be intermittent - making it harder to identify.

Sources of Crosstalk:

  • Network cables
  • AV cables
  • Other copper wires within a single AV cable
Mitigating Electromagnetic Interference and Crosstalk
Methods to Mitigate EMI and Crosstalk include:
  • ensuring cables are separated from the following sources of EMI by:
    • at least 600mm from unshielded electrical power cabling;
    • at least 150mm from electrical power cabling within a grounded metal conduit;
    • at least 1m from electrical motors and transformers.
  • running AV cables within conduit material to provide shielding from EMI:
  • using balanced / shielded cables where possible;
  • using cables with thicker gauge (lower AWG);
  • using cables with thicker dielectric insulating material;
  • using cables with thicker outer jacket material.

Cabling for Equipment Racks

Consider the following in regard to cabling for equipment racks:
  • All inter-rack and intra-rack cabling should be neatly laced, dressed and adequately supported
  • All exposed cable should be dressed with heavy duty neoprene heat-shrink tubing
  • Lacing bars should be fixed to the rear of the rack behind any active or passive equipment, or rear panel of patchbays
  • Bar-loop cable management modules should be mounted directly below any patchbays at the front of the rack
  • Installed rack cables should be fastened at regular intervals so there are no sagging segments of cable
  • Cable length should be specified appropriately for the required distance between devices, minimising excess
  • Any excess cable length should be coiled and fastened near to one end of the cable taking care not to exceed the specified bend radius of the cable
  • Route all cable and wiring within equipment racks and joinery according to function, separating wires of different signal levels (microphone, line level, amplifier output, AC, intercom, etc.) by as much distance as possible. Neatly arrange and bundle all cable with removable/reusable plastic or Velcro ties according to the organisation’s requirements.
  • Unshielded / unbalanced cables should be as far away from other services and cabling as possible:
    • Run DC and AC power cables on one side of the rack
    • Run AV signal cables on the opposite side of the rack
  • Cables typically follow an orthogonal path (vertically along rack rails, horizontally along lacing bars)
  • Intersecting cable paths should do so perpendicularly
  • Typical operating temperatures are 10 to +60 degrees Celsius. Ensure cables are not exposed to any sources of extreme heat or extreme cold
  • Bundle the cables that run from the rack to the field into two segregated looms:
    • All DC and AC power cables bundled together
    • All AV signal cables bundles together
  • If maintenance and servicing requires the rack be moved for better access to the equipment within, the cables that run from the rack to the field should allow at least 2 metres slack
  • It is typically the AV contractor’s responsibility to organise all signal and power cables which connect equipment racks to adjacent electrical devices.
    • These cables shall be bundled and installed within black nylon woven mesh fabric. This fabric jacket shall be manufactured for such purposes and shall be sized appropriately to the quantities and sizes of cables contained within.
  • Where there are multiple adjacent equipment racks, the looming shall alternate. For example, as viewed from the rear, all power cables, control cables and high level cables shall be run on the right side. For the next rack, these shall be on the left side and the low level cables on the right. This scheme will alternate from rack to rack, ensuring maximum spacing.

Fly Leads, Exposed Cables and Cable Looms

Consider the following regarding flyleads and exposed cables:
  • Any visible cables should be dressed in a braided cable loom
  • Flylead cables should be bundled and dressed in a braided cable loom
  • Flylead cables should be long enough to connect to ports on both left and right-hand side of user devices for use on the work surface

Labelling

All connectors, patch leads, audio/video leads, controls, equipment and components, terminal blocks and equipment racks must be permanently labelled in an approved format.
Consider the following as a list of priorities regarding cable labels:
  • Cable labels should be clearly legible
  • Any cable numbers should match the cable numbers used for AV system connectivity diagrams (schematics)
  • Every AV cable should be labelled at both ends whether terminated or not - there should be no unlabelled cables
  • Wrap-around cable labels protect the printed ink with a clear adhesive plastic tag
  • A cable label should indicate the intended function of the cable
  • Cable labels should ideally be duplicated vertically on each label so that they can be read without the need to twist cables in-situ.
All fixed labels, other than those affixed to cables, should be permanently engraved in metal or plastic laminate and fixed to rack-housing/shelving, rather than active equipment. Labelling should be shown on AV shop drawings.

Example Cable Label Convention

Colour Codes
Consider the following regarding cable colour codes:
  • There is no universal convention for colour codes
  • Colours may be used to easily identify cables by function, system, or signal flow direction
  • Colour may be applied to the following:
  • Cable jacket
  • Cable plug
  • Cable label
  • Connection plate label
  • Patchbay label

Cable Types and Signal Information

This section provides a series of reference tables for common AV cable types and signals encountered throughout the design process. It is informational only, and specific performance will differ between manufacturers and products.
All maximum recommended lengths assume no interim adaptors between termination points, unless otherwise noted.

Digital Video: HDMI, DVI-D, DisplayPort

Cable Specifications
Cable Type
Conducting Material
Typical Conductor Gauge / Diameter
Shield Material
HDMI 1.4 Standard
(10.2Gbps)
Oxygen-free copper; or Tinned copper
22-24 AWG
(~0.6mm)
Foil tape, drain wire; and
Braided sheath
HDMI 2.0 Standard
(18Gbps)
Oxygen-free copper; or Tinned copper
22-24 AWG
(~0.6mm)
Foil tape, drain wire; and
Braided sheath
HDMI 2.1 Standard
(48Gbps)
Oxygen-free copper; or Tinned copper
22-24 AWG
(~0.6mm)
Foil tape, drain wire; and
Braided sheath
DVI Single-Link
(4.95 Gbps)
Solid copper
22-24 AWG
(~0.6mm)
Drain wire
DVI Dual-Link
(10.2 Gbps)
Solid copper
22-24 AWG
(~0.6mm)
Drain wire
DisplayPort 1.2 Standard
(21.6 Gbps)
Oxygen-free copper; or Tinned copper
28 AWG
(0.32mm)
Braided sheath
DisplayPort 1.4 Standard
(32.4 Gbps)
Oxygen-free copper; or Tinned copper
28 AWG
(0.32mm)
Braided sheath
AV Signals, Connectors and Maximum Recommended Cable Length
AV Signal
Typical Connectors
Maximum Recommended Cable Length
HDMI - RGB/YCbCr 4:4:4
(Video, Audio, Ethernet, CEC, EDID, HDCP)
HDMI;
Mini HDMI;
Micro HDMI
12m (<1.5Gbps),
3m (18Gbps)
DVI Single-Link - RGB
(Video, EDID)
DVI-D;
DVI-I
12m (<1.5Gbps),
7m (4.95Gbps)
DVI Dual-Link - RGB
(Video, EDID)
DVI-D;
DVI-I
12m (<1.5Gbps),
5m (10.2Gbps)
DisplayPort - RGB/YCbCr 4:4:4
(Video, Audio, USB, CEC, EDID, HDCP)
DisplayPort;
Mini DisplayPort
12m (<1.5Gbps),
3m (21.6Gbps)
Digital Video Maximum Cable Length by Bandwidth
The following table is a reference for recommended maximum cable lengths for digital video data bandwidth by resolution, framerate, colour depth, and chroma subsampling:
Resolution /
Framerate
Colour Depth /
Chroma Subsampling
Approximate
Bandwidth (Gbps)
Maximum Recommended Cable Length
720p
1280x720 60Hz
24-bit Colour
YCbCr 4:2:2
1.0
12m
720p
1280x720 60Hz
24-bit Colour
RGB/YCbCr 4:4:4
1.5
12m
720p
1280x720 60Hz
30-bit Colour
RGB/YCbCr 4:4:4
1.8
9m
1080p
1920x1080 60Hz
24-bit Colour
YCbCr 4:2:2
2.1
9m
1080p
1920x1080 60Hz
24-bit Colour
RGB/YCbCr 4:4:4
3.2
9m
1080p
1920x1080 60Hz
30-bit Colour
RGB/YCbCr 4:4:4
4.0
7m
UHD 30
3840x2160 30Hz
24-bit Colour
YCbCr 4:2:2
4.1
7m
UHD 30
3840x2160 30Hz
24-bit Colour
RGB/YCbCr 4:4:4
6.2
5m
UHD 30
3840x2160 30Hz
30-bit Colour
RGB/YCbCr 4:4:4
7.7
5m
4K 30
4096x2160 30Hz
24-bit Colour
YCbCr 4:2:2
4.4
7m
4K 30
4096x2160 30Hz
24-bit Colour
RGB/YCbCr 4:4:4
6.6
5m
4K 30
4096x2160 30Hz
30-bit Colour
RGB/YCbCr 4:4:4
8.2
5m
UHD 60
3840x2160 60Hz
24-bit Colour