1 © 2013 InfoComm International CTS Prep Part One.

1© 2013 InfoComm International

CTS PrepPart One


Certified Technology Specialist Professionals

• Know the “big picture” of the AV industry– Disciplines within the AV industry– Allied industries– AV project cycle

• Know the technical scope of general projects

Ch 1


Disciplines within the AV Industry

ManufacturersSystems

IntegratorsRental & Staging

Companies

IndependentConsultants

Technology Managers

Value-addedDealers

Distributors PresentationProfessionals


Allied Industries

ArchitecturalArchitecture, Interior

Design, Carpentry

ElectricalPower, Infrastructure,

Lighting

Mechanical/HVACVentilation, Fire Suppression

StructuralStructural Engineering, Rigging,

Seismic


The AV Project Cycle


Technical Scope of General Projects• Boardroom• Auditorium• Training room• Divisible conference room


Questions?


Part One

• Domain A: Creating AV Solutions – Gather Information– Needs Analysis– Site Survey– Maintain Awareness of Changes

& Create Scope– Determine AV Solution

Components


Gather Information

• Determine what the customer wants

• Obtain scale drawings• Obtain customer

budget • Obtain customer

constraints (work hours, noise levels, cultural issues)

Ch 11


Domain A: Creating AV Solutions

Gather Information• Needs Analysis• Site Survey• Maintain Awareness of

Changes & Create Scope• Determine AV Solution

Components


Needs Analysis

• What is a needs analysis?• Why is it important?

Ch 11 – Pg 191


Needs Analysis

• What information is needed?– Determine what the customer wants – Obtain scale drawings– Obtain customer budget – Obtain customer constraints (work hours, noise levels,

cultural issues)

• Determine the end user’s needs by determining the following.– The required application(s) based on the user’s needs– The tasks and functions that support the application– The wishes and desires of the end-user

Ch 11 – Pg 191


Gather Information

• Needs Analysis Exercise– Facts to be conveyed.– How to be conveyed.– How it takes shape.

Remember! No equipment

discussions!Ch 11



Gather InformationNeeds Analysis• Site Survey• Maintain Awareness of


Components


Evaluate Site Environment

• Site Survey Exercise

Ch 12 and 13



Gather InformationNeeds AnalysisSite Survey• Maintain Awareness of


Components


• Exercises– Maintain Awareness of Changes

• Review potential changes in Chapter 14 of the CTS Exam Guide, Second Edition

– Individually Develop a Functional AV Scope• Review the example of a scope in your student binders• Write a brief scope of you group’s project.• Present findings to contact (designated student) of the

recommendations.

Maintain Awareness of Changes, Develop a Functional AV Scope Exercises

Ch 14 and 15



Gather InformationNeeds AnalysisSite SurveyMaintain Awareness of


Components


Determine AV solution components• Room Features• View-ability• Aspect Ratio • Projection Throw • Viewing Parameters• Audio• Project Documentation


Rooms Features

• Space for Presenter and Equipment• Location of Equipment• Space for the Audience• Accessibility to the Room• Accessibility to the Equipment• Control Room Size• Rear Projection Room Size• Doors• Finishes within the Room

Ch 14


Image View-ability Factors

• Size• Shape• Target of vision (screen)• Obstructions• Brightness• Contrast

Ch 5 and 14


Aspect Ratio

• Width dimension of a picture expressed relative to the height dimensions.

• The aspect ratio of all broadcast composite video systems is 4 units wide by 3 units high , also written as 4:3 and 1.33 (analog).

• The aspect ratio of HD can be 16 units wide by 9 units high also written as 16:9 and 1.78

Ch 5 – Pg 99


Aspect Ratio Exercises


Determine AV solution componentsRoom FeaturesView-abilityAspect Ratio • Projection Throw • Viewing Parameters• Audio• Project Documentation


Projection Throw

• Projection Optics• Keystone• There are three dimensions to projector placement - all in

relationship to the desired image dimensions and location• Use projector manual to determine location• Calculate Projection Throw Exercise


Determine AV solution componentsRoom FeaturesView-abilityAspect Ratio Projection Throw • Viewing Parameters• Audio• Project Documentation


Viewing Parameters

• Perception Limitations• Viewing requirements of the Task• Text Size (or detail) to be displayed• Viewing Distances• Image (and hence screen) Height• Aspect Ratio of Image

:


Determining Image Size

• The maximum viewing distance is based on the amount of detail we need to see in the image, not the resolution of the image.

• What is the Task?– To View: General Viewing– To Read: Detail Viewing with Clues (like this

slide)– To Inspect: Detail Viewing without Clues


Reading (With Clues)


Inspection (No Clues)


Determining Image Size

• Rules of Thumb: Image height equals the distance to the furthest viewer divided by:– 8 for General Viewing Tasks, – 6 for Detailed Viewing Tasks, or – 4 for Inspection Viewing Tasks.


Required Image Height

• Furthest Viewer is 24 feet away. • What is the image height for:

– General Images? – Detailed Images?– Inspection Images?


Required Image Height

• Furthest Viewer is 32 feet away. • What is the image height for:

– General Images?– Detailed Images?– Inspection Images?


Character Height

height

Maximum of 150 x height

General Rule


Nearest Viewer

• How Close Can the Nearest Viewer Be? • The correct answer is?

– The Image Width

• First Row -- No closer to the Image than the width of the IMAGE

Image Width I.W.


Nearest Viewer

• How Close Can the Nearest Viewer Be?• An additional criterion is based on the

vertical angle of view

15° Max to Center of Image if possible.

0

30° Max to Top of Image if possible.


Viewing Area

• Where should the seats be (and where should they not be) for the image to be useful to the entire audience based on the required tasks?


Viewing Angles

180 Viewing Angle 90 Viewing Angle

On Axis

45° 45°

On Axis


Defining the Viewing Area

• The best viewing is on axis to the image.• The maximum off-axis viewing angle will

be dependent on the characteristics of the screen.



• The widest viewing angles are provided by:– Direct-view displays– Matte white front projection screen material – Diffusion rear projection screens

• High-gain projection screens can limit viewing angles



• The “good” viewing area is within 45 degrees of the projection axis or within a 90 degree viewing cone.

90

45



• The “acceptable” viewing areas are within 45 degrees of the edge of the image

45

45


Determine AV solution componentsRoom FeaturesView-abilityAspect Ratio Projection Throw Viewing Parameters• Audio• Project Documentation


Audio

• Types of Audio Systems • Speech Reinforcement (also: “Mix-Minus”)• Program Playback• Paging• Background Music• Noise Masking• Audio conference (also: Audio for VTC )

Ch 4 and 16


Speech Reinforcement System

• In order to work properly, a sound system must do three things:– It must be Loud Enough– It must be Intelligible– It must remain Stable

Ch 16 – Pg 310


Loud Enough

• Achieves target level– 25 dB signal to noise

• Same level to all ears +/- 3 dB• No perceived distortion (<1% THD)• Adequate electrical signal to noise

(>60dB)


Intelligible

• Good direct to reflected (reverberant) ratio• Meets desired frequency response


Stable

• Allows sufficient gain before feedback with headroom


Ohm’s Law

• Expresses the relationships between Voltage, Current and Resistance in an electrical circuit

• Helps calculate the Power in a circuit– if you know any 2 values, you can find the third one.

Appendix C – Pg 546


Ohm’s Law



Ohm’s Law Example

LOAD100 ohmsR

VOLTAGESOURCE

100V

+-



• Expressed in amps by the symbol I• The flow of electrons in a circuit• In a DC circuit the flow is in one direction

only (minus to plus?)• In an AC circuit the flow reverses

periodically.

I=V/R

Current


Voltage

• The force that causes the electrons to flow.• Expressed in Volts or V (or E)• Mic level is 0.001 - 0.003 V (1 – 3 mV)• Line level is 0.3V (semipro) or 1.23 V(pro)• Loudspeaker level is 4 V or more

V=I * R



Resistance

• The opposition to the flow of electrons• Expressed in ohms and R• Applies to DC (like from a battery).

R=V/I



Impedance

• Like resistance, but applied to Alternating Current. (Audio signals, radio signals, the power from the wall)

• Expressed in ohms and Z

• Important for loudspeakers, power amps, and connecting the inputs and outputs of equipment.

Ch 9 – Pg 161-164


Audio Systems

• Loudspeakers have a characteristic impedance

• Impedance is the opposition to alternating current flow

• A common loudspeaker has an impedance of 4, 6 or 8 Ω


Power

• The work done by the flow of current• Measured in watts

P = V*I



Ohm’s Law Exercise

PowerAmp

100w 8 ohms

Calculate the current and voltage in this circuit



Loudspeakers Wired in Series• Total Impedance (Z) = Z1 + Z2 + Z3…

• If you have 4 loudspeakers, each rated at 4 ohms…

• Z = 4 + 4 + 4 + 4• Z = 16 ohms

• Therefore, an amplifier that is rated for a 16 ohm load would be the best choice. An amp optimized for a 4 ohm load could not couple energy efficiently to this circuit of loudspeakers.

Ch 16 – Pg 321-323


Loudspeakers Wired in ParallelFormula for parallel resistance and

impedance 1

ZT = 1 1 1 1

Z1 Z2 Z3 … ZN


Loudspeakers Wired in a Series Parallel Circuit


Audio Systems• Amplifiers have an output impedance they are

expecting to have connected to their output terminals

• Matching this output impedance with the loudspeaker load maximizes energy transfer from amplifier to loudspeaker to acoustic energy


Audio Systems

• A transformer added to a loudspeaker will increase the impedance of that loudspeaker to the amp


Constant Voltage

Ch 16– Pg 323 - 325


The Decibel

• Expresses sound and signal levels in a way that is easier to work with and closer to the way we experience them.

• Comes in two basic flavors:– 1 – Power– 2 – Voltage/Pressure/SPL



Power Decibels Exercise

• dB=10 * log (P1/P2)

P1 is the power change (to) value

P2 is the power reference (from) value


Distance and Voltage Decibels Exercise

• dB=20 * log (D1/D2)

• dB=20 * log (V2/V1)

D1 or V1 is the reference (from) value

D2 or V2 is the change (to) value


Loudspeaker Directivity

• The angle over which a speaker radiates• Usually shown on a plot• Dispersion pattern varies with frequency

Ch 5, Pg 64-65


Loudspeaker Directivity

Ch 5, Pg 64-65


50% Overlap (center-to-center)

• Pros– Excellent coverage at most

frequencies (1.2 dB variation)

• Cons– Costly– Maybe coverage is better than

required– Negative interaction from nearby

loudspeakers– Adds too much acoustical energy to

space


Edge-To-Edge

• Pros– Acceptable coverage at main speech

frequencies (5.4 dB variation)– Inexpensive– Minimum interaction of loudspeakers

with each other and room

• Cons– May have uneven frequency response– May have some low spots in corners


Partial Overlap• Pros

– Very good coverage at most frequencies(2.6 dB variation)

– Good middle-of-the road design– Ensures few or no low spots

• Cons– May not be as even in frequency

response– Some negative interaction from

nearby loudspeakers– Adds some acoustical energy to space


Determine AV solution componentsRoom FeaturesView-abilityAspect Ratio Projection Throw Viewing ParametersAudio• Project Documentation


Project Documentation

• Contract Documents• Project Drawings• Project Specifications

Ch 15 and 16


AV Project Drawings

• Riser Diagrams• Block Diagrams• Plate Details• Panel Layouts• Equipment Rack Layouts• Details• Shop & Submittal Drawings

Ch 15 and 16


Types of Drawings

• Index• Notes• Floor Plans• Reflected Ceiling Plans• Sections• Elevations• Details

Ch 12 – Pg 216-230


Reading Blueprints

• Orientation Schedules• Notes• Abbreviations• Symbols/Icons

Ch 12 – Pg 216-230


Reading Blueprints - General


Abbreviations

• AFF Above Finished Floor• AFP Above Finished Platform or Raised

Floor• AS Above Slab• CL Center Line• DIA Diameter• DR Door• E East

CL


Abbreviations

• EC Empty Conduit• (E) Existing• EL Elevation• ELEC Electrical• MISC Miscellaneous• NIC Not In Contract• NTS Not To Scale• OC On Center• OD Outer Diameter


Abbreviations

• OFCI Owner Furnished Contractor Installed

• OFOI Owner Furnished Owner Installed• RCP Reflected Ceiling Plan• SECT Section• UBC Uniform Building Code• VIF Verify In Field


Scales

• It would be difficult to draw at full size so things are “scaled down”

• 1/4 and 1/8 typical• Other Scales for Details

0 1’ 10’

1/4” = 1’- 0”

1’ 5’ 10’

20’0

1/8” = 1’- 0”

Ch 12 – Pg 226 - 228


Floor Plans

• Slice through the building at 4 feet above the floor

Ch 12 – Pg 217


Reflected Ceiling

• Ceiling Grid• Diffusers• Fluorescent Lights• Down Lights• Sprinklers• Projection System• Loudspeakers

Ch 12 – Pg 217


Reflected Ceiling Plans• The floor is a mirror

S

S

S SS

S

S

SS

S

S

Ch 12 – Pg 217


Symbols/Icons

• Every Project has different symbols and icons.

• As long as they are defined in a key or legend, the actual object does not matter.

Ch 12– Pg 228


Symbols/Icons

• Column Lines• Orient point of circles to column line.

Letters in one direction. Numbers in the other direction. Also shows as a grid on drawing.

1

A


Symbols/Icons

• Match Lines• Shaded portion is the side considered


Symbols/Icons

• Elevation Flags• D1, 2, 3 and 4 : Elevation Identification• A4.0 : Drawing where elevation drawn

D4

A4.0 D1

D2

D3


Symbols/Icons

• Section Cuts

Top # : Section Identification

Bottom # : Drawing where section is drawn

D1

A3.0


Sections

• Cut through the room you are working in -- just like cutting an orange


Sections

A3.0D2

A3.0D1

A3.0D2

A3.0D1

A3.0D4

A3.0D4

A3.0D3

A3.0D3

A3.0D5

A3.0D5

Ch 12 – Pg 221


Section 1• Straight to the north at CL

A3.0D1 Section D1-D1

Ch 12 – Pg 221


Symbols/Icons

• Detail Flags

A5.625

Top # : Detail Information

Bottom # : Drawing where detail is drawn.


Details

• Small items that need to be blown up to show how they need to be installed.

• Too small to draw or see at the project’s typical drawing scale.

Ch 12 – Pg 221


Video Projector Detail

VIDEO PROJECTOR MOUNTING DETAIL


Determine AV solution componentsRoom FeaturesView-abilityAspect Ratio Projection Throw Viewing ParametersAudioProject Documentation


Design AV Solution Exercise

• Create specifications• Create bill of materials (BOM)• Design a floor elevation• Develop block diagram



Gather InformationNeeds AnalysisSite SurveyMaintain Awareness of

Changes & Create ScopeDetermine AV Solution

Components


CTS Prep Homework

• Homework: Sample exam – Self score• Homework: Complete CTS self-assessment

checklist• Use the information from the self

assessment and exam to determine self-directed breakouts.

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