making sense of a/v. agenda understanding signal types –video, audio and control signals...
TRANSCRIPT
Making Sense of A/V
Agenda
• Understanding Signal Types– Video, Audio and Control Signals
• Minimizing Loss and Maximizing Performance– Environmental and Length Limitations
– Best Installation Practices
• What’s Next?– What Does the Future Hold?
Understanding Signal Types
Video Signal Technology
• Video Can Be Digital or Analog– Digital = SDI, HDMI, or DVI
– Analog = Component, S-Video or Composite Video
– RF = CATV, MATV or Satellite IF
• A Signal Can Be Sourced In Either The Digital or Analog Domain– The Signal Can Change Formats Depending on
Components Installed!
Digital Video Defined
• Digital Video Transport Is Independent of the Various HDTV Standards Such As ATSC, DVB(-T,-S,-C)– These Are Encapsulations of the MPEG Data Streams, Which Are
Passed off to a Decoder, and Output As Uncompressed High-Resolution Video Data
– This Video Data Is Then Encoded Into TMDS for Transmission Digitally Over HDMI or DVI-D
• A Single DVI Link Consists of Four Twisted Pairs of Wire (Red, Green, Blue, and Clock) to Transmit 24 Bits Per Pixel– Because There Is No Error Correction Or Packetization, Maximum
Interconnect Length Is Hard Limited Based On System Impedance– System Impedance Is Very Difficult To Control In A Twisted Pair
Configuration
Digital HDTV/SDTV Signals
• SDI – Serial Digital Interface– Professional Standard, Never Used on Consumer Product
– Uses Coaxial Cable (RG6) for Transmission
• HDMI – High Definition Multimedia Interface– HDTV Digital Video to 1080p Resolution
• Same As DVI Single Link!
– Includes Eight Channel, 24 Bit Digital Audio and Control Signals• This Connection Consolidates Audio and Video Into One Simple
Cable!
– Includes Inter-Component Operability Commands• Allows DVD Player to Control A/V Pre-Pro and Display Device
– HDMI LLC Quality Control Through Testing Labs Certification
Digital Video Signals
• DVI – Digital Visual Interface– Transmission Minimized Differential Signaling
• This Transmission Standard Was Adopted by HDMI LLC
• TMDS Does Not Incorporate Error Correction
– There Are Multiple DVI “Flavors”• DVI-A, Analog Signal That Is The Equivalent of SVGA
• DVI- I, Includes Both Analog and Digital Transport Ability
• DVI-D, Digital Video Only– Single Link (<2.3M Pixels) Supports Up To 1920 X 1080
– Dual Link (>2.3M Pixels) Supports Up To 2560 X 1600
• VESA M1-DA– Data Connection Standard Promoted by In-Focus
• Incorporates USB As Well As Digital and Analog Video Ability
Press Play on DVD
Automatically…Turns on A/V Rcvr
Automatically…Turns on TV
Automatically…Switches to correct input
(from DVD player)
Automatically…Switches to correct input
(from A/V Receiver)
And then…Plays DVD
Consumer Electronics Control
• Allows user to control all HDMI devices with TV remote– Can control DVD player by pointing remote at the TV
• Enables high-level functions such as “one-touch play” :
HDMI Cable Construction
DVI-D Dual Link Construction
Analog HDTV Video Signals
Component Video Means Signals Are Transported as Separate B&W, Color and Sync Segments– RGBHV Sends Signals as Red, Green, Blue, Horizontal and
Vertical Sync– RGBS Sends Signals as Red, Green, Blue and Multiplexed
Sync– Component Sends Signals As R-Y, B-Y and Y
• Y Is the Luminance Channel, B-Y (also called U or Cb) Is the Blue Component Minus the Luminance Information, and R-Y (also called V or Cr) Is the Red Component Minus the Luminance Information
• Component Can Also Send Signals As RGB – This Is A Computer Display Standard
Analog HDTV Connectors
RGBHV Component
Standard Resolution (SD) Analog Video
• S-Video Was Introduced by JVC in the 1980’s– S-Video Transports the Image As Separate Color
(Chroma) and Black&White (Luma) Information
– S-Video Is Ubiquitous on Current Products
• Composite Video Is A Single Wire Standard– Uses a Single 75-Ohm Coaxial Cable
– Supports Up To 500 Lines of Resolution
SD Analog Video Connectors
S-Video (4-Pin DIN)
Composite VideoRF MATV/CATV
S-Video Cable Construction
Coaxial Cable Construction
Audio Signal Technology
Digital Audio Signals
• AES/EBU Balanced Digital Audio– AES3 Is a Professional, Balanced, Digital Audio Transfer
Standard
• AT&T ST Optical Digital Transfer
• S/PDIF Digital Audio– Is an Acronym for Sony Philips Digital Interface and Is a CD
“Red Book” Standard Digital Audio Transfer File Format
• TOSLINK Optical Digital Audio– JISF05 Is an Optical Transfer File Format that Incorporates
S/PDIF Data Formatting and Converts the Signal to LED Sourced Optical Transmission
Digital Audio Connectors
S/PDIF Uses the Same 75-Ohm Coaxial Cable as Composite and Component Video
TOSLINK Uses Single or Multiple Plastic – or Multiple Quartz Glass – Conductors
Analog Audio Signals
• XLR Balanced Audio Connections – Originally the "Cannon X" Series, Subsequent Versions Added a Latch
("Cannon XL") and Then a Rubber Gasket, Which Led to the Acronym XLR.
– Utilizes 2 Conductors (Like S-video) to Carry Positive and Negative Halves of the Audio Signal, Thus Minimizing Common Mode Noise
• Single-ended (RCA) Audio Connections – Single Ended Interconnects Are of a Coaxial, Unshielded Twisted Pair
(UTP), or Shielded Twisted Pair Topology– The Signal Is Carried on One Conductor and the Ground Reference Is
Carried on Another.
• Speaker Level Connections– Low Impedance, Low Voltage Connection for High Performance– 70-volt Systems Are Ideal for Longer Wire Runs, Distributed Background
Music • Higher Voltage and Lower Current Maximize Efficiency
Analog Audio Connectors
XLR
RCA
Speaker Level
Analog Audio Interconnect Construction
System Control Wiring
Audio and Video Control
• Sophisticated Control Systems Capable of Operating Audio, Video, Lighting, Security and Environmental Controls Are a Critical Component of a Well Designed Installation
• Almost All CE Control Systems Require Dedicated CAT5e Wiring
– Some Sophisticated Systems Require RS232 or Other, Proprietary Wiring
• Understanding Who Will Use The System Will Define The Control Requirements
System Control Wiring Plan
• Planning For, and Providing, a System Control Infrastructure Ensures Futures Sales Opportunities– Give Your Customers the Ability to Add, Improve and Enlarge
– Scalability Is Not Just for Software!
• Understanding the Importance of Control Is a Key Differentiator for Successful A/V Integration– Your Customer Is Relying on YOU to Provide Answers to
Questions They Haven’t Even Asked!
• Consider Where the User Will Be, Who the User Will Be, What the System Will Be Used For, How the System Might Evolve– Your Wiring Strategy Must Fill Immediate Needs and Anticipate
Future Requirements
Example of a Multi-Room Single-Zone Background Music System Control Configuration – Xantech Product Shown
The Installation Environment
HDMI and DVI Limitations
• HDMI and DVI Have Identical Length Limitations– Somewhat Affected by Source and Display Build Quality– Somewhat Affected by Tight Bends or Noisy Environment– HDMI and DVI Signals Can Exhibit “Snow” and Drop-Outs
• The Longest Practical Installation Length Is 10 Meters– Copper Connections to 20 Meters Are Available
• Built In Signal Repeaters Make Some “Active” Cables Capable of 40 Meters
• Add-on Signal Boosters Allow Up To Two 20 Meter Runs To Be Connected
• Optical Conversion Allows DVI Runs Up To 200 Meters – Use Caution Due To HDCP Limitations With Optical Solutions
HDMI and DVI Limitations
• HDMI and DVI Connections Don’t Transport Analog Content – A Good Installation Is Versatile!– If A System Has Only An HDMI or DVI Input, It Won’t
Be Compatible With Composite Video, S-Video or Component Video Sources Unless An Active Converter Is Used
– HDCP (High Definition Content Protection) May Limit The Application of Active Devices
• Conversion of HD Digital Signals To Analog Component Is Not Supported
• Up Conversion Of HD Component To HD Digital May Be Supported
HDMI and DVI Limitations
HDMI and DVI Are Susceptible To Environmental Interference
– RFI Is Radio Frequency Interference• Possible Sources Include High Speed Digital Processors, RF
Transmitters, Faulty Dimmers and Switches
– EMI Is Electromagnetic Interference• Typically Lower Frequency Variation of the Above
• Main Source of EMI Is From Electrical Power Circuits and Devices
– RFI and EMI Diminish As A Function of the Square of the Distance
• A Source of RFI or EMI Is 144 Times Smaller @ 1 Foot From the Source Than It Is At 1 Inch From the Source
An Example Of How NOT To Run A DVI Cable!
Analog Audio/Video Limitations
Analog Video Is Very Robust
– Signal Runs to 300 Feet Or More Are Not A Problem
– Characteristic Impedance of the Cable Must Be 75-ohms For Maximum Performance
• Cable Impedance Is Determined By The Geometric Relationship Of the Conductor and Dielectric Size and Shape
– Signal Levels Can Be Easily Amplified For Distribution
– Quality Shielding Virtually Eliminates Problems
Analog Video Limitations
• Use a Quality Distribution Amp
• Avoid Tight Bends In Coaxial Cable
• Use A Minimum Of Dual Shielded Cable– Foil and Braid
– RG-6 Is Best For Longer Runs
• Use Quality Crimp Tools and Coax Strippers For Best Results
Best Practices – the Importance of a Wiring
Strategy
Let’s Install a System Now
We’ve been asked to install a multi-media system in a conference room. The project requires:
• ceiling mounted projector capable of displaying an HDTV image in 16:9 on a perforated screen.
• sound system must support full 7.1EX Dolby Digital and DTS decoding.
• In-wall speakers will be installed to the left and right of the screen, with the center channel behind the screen.
• powered subwoofer
• in-ceiling speakers are spec’d for rear channel support.
• All product will be in an equipment closet.
What do we need to install for the pre-wire portion of the project?
NEC and Wire “Class”
The Pre-Wire Continued
• To Handle the Speakers We’ll Install a 14/2 CL2 From Each Speaker Back-box to the Equipment Closet
• The Subwoofer Requires a Line-level Connection. We’ll Run an RG-6 Coax From the Equipment Closet to a Wall-plate Positioned Close to the Electrical Outlet That Will Power the Subwoofer
• Since We Aren’t Sure How System Control Will Be Handled, We’ll Run a Length of Cat5e From the Equipment Closet to the Projector Location and to the Screen Location for Possible Installation of IR Targets. We’ll also run a CAT5e to a location near the lighting control for possible installation of a keypad.
• The Projector Will Need to Handle Digital Signals As Well As Analog Signals. To Cover the Full Spectrum of Possibilities We’ll Run Five (5) RG-6 Coaxial Cables to Handle the Component and S-video Signals. We’ll Also Run an HDMI or DVI-D Dual Link to Handle Digital Video.
Optimizing The Media System Installation
• Run Five (5) Coaxial Cables from the Projector to the Equipment Rack– Three for Component,
Two for S-Video
• Run DVI-D Dual Link or HDMI from the Projector to the Rack
• Rack Mount All Components If At All Possible– Better Ventilation and
Access
What About Distributed Music?
• Establish The Basic Design– Foreground or Background?
– Can All Wires Be “Home Run”
– Where Is The Primary Listening Location For Each Room or Zone?
– How Large Is the Volume of the Room or Zone?
• Determine The Number of Speaker Pairs to Be Installed– More Speakers At Lower Volume Are Preferable To Fewer Speakers at
Higher Volume
• Determine the Desired Average Playback Level– It Is Important to Understand the Type of Music to Be Played!
• Determine Other Structural Wiring Runs In Order To Avoid Trouble
– A/V Wiring Should Be Kept At Least 6” From AC Wiring
– Avoid Running A/V Wiring Parallel to AC
– When Crossing An AC Mains, Do So At A Right Angle
Multi-Room vs Multi-Zone
• What Is Multi-Room?– A System That Can Deliver One Source to
Multiple Locations Simultaneously
• What Is Multi-Zone?– A System That Can Deliver More Than One
Source Simultaneously To More Than One Location
• Always Pre-Wire For Multi-Zone!
Multi-Room or Multi-Zone, The Game’s The Same…
• For Best Performance, All Speaker Wires Must Be “Home Run”
• In Each Room or Listening Location, Determine the Best Spot for the Speakers and the Local Control– If the Project Doesn’t Call for Local Control, Wire for Them for
Future Application! The End-user Will Want Them Sooner Rather Than Later! No Accessible Infrastructure Means No Additional Sales! Always “Set The Table”!
• The Run From the Equipment Closet to the “Volume Control” Location Is Done With a 4-conductor Cl2 Wire– Using a Composite 14/4 & Cat5e Allows You to Pull One Run
and Cover Both Speaker and Control Requirements. Maximize Efficiency and Through That, Profit!
• The Run From the “Volume Control” Location to the Actual Speakers Can Be Via a Looped 4-conductor or a Single Run of 2-conductor
Other Issues To Consider
• Distributed Music Systems Require Some Type Of Impedance Matching Distribution Transformer– Most Amplifiers Won’t Drive Loads Lower Than 2 Ohms
– Each Additional Pair Of Speakers Halves The System Impedance
• Speaker Switching Must Be Considered– Does The Installation Require All Zones To Be Controlled
From A Single Location, From The Remote Location, Or From Both?
• Think Scalability– It’s Not Only Possible, But Easy To Take A Multi-Room
System To A Multi-Zone System If The Structural Wiring Supports The Upgrade!
70-Volt Distribution Basics
• 70-Volt Is Used For Background Only– Each Speaker “Drop” Uses A Step-Down Transformer
• Typically Built Into The Speaker Itself
– Appropriate for Restaurants, Common Spaces, Paging
• Higher Voltage and Lower Current Means Lower Losses and Greater Efficiency of the System– A 25-Volt System Can Also Power 70-Volt Speakers
• Uses The Same CL2 or CL3 Speaker Wire As Direct Distribution
The Future
High Definition Media
• HDCP - High Definition Content Protection– Digital Only Method Of Preventing Content Piracy
• Analog HDTV Transport May Be Limited In The Future
– Running Multi-mode Fiber May Allow For Future Growth
• Where Might You Encounter HDCP?– ATSC and Off Air Broadcast
– DBS Satellite Broadcast• Private Networks
– Digital Cable Broadcast
– HD-DVD and Blu-Ray DVD
Broadcast
• FCC Is Currently Working To Eliminate Analog Satellite Broadcast From C-band– C-band Is the Key Delivery Vehicle for All Network and
Premium Channel Programming
– SCPC and MCPC Transmissions Are Moving Private Networks Towards a Digital Future
• Terrestrial Broadcasting Is Migrating Towards a Total Digital Environment’– New Channels, New Capacity, New Content for the Viewer
• Your Wiring Strategy Must Include Provisions For DBS And Terrestrial Antenna Installation
Broadcast over IP?
• Streaming Media WILL Become a Consumer Medium– Incorporate Network Connectivity Into the Audio/Video
Environment
• Think “NARROWCASTING”– Open Media Network, Http://www.Omn.Org/
The Computer as a Media Component
• Media Servers ARE A Mainstream Component!– Multi-Media Content Servers
• Provide Access to Music, Movies, Photos
• Multi-Room, Multi-Zone
– Music/Audio Content Servers• Models From Escient, Apple,
Kenwood, Denon and Others Are Ubiquitous
– HTPC• Home Theater Personal
Computer
The Results of a good wiring strategy
• Increase Your Bottom Line
• Improve Customer Satisfaction
• Ensure Repeat Business
Optimize The Pre-Wire!Take Time To Determine What
Your Customer Wants, Even If It’s Not In The
Budget… Yet!