Term
| •WHAT ARE THE 3 PRIMARY FACTORS DETERMINING POWER LOSS IN SPEAKER CABLE RUNS? |
|
Definition
|
|
Term
| •NAME 3 ELEMENTS THAT HAVE THE GREATEST EFFECT ON SYSTEM DESIGN? |
|
Definition
|
|
Term
| •NAME 3 TYPES OF SPEECH INTELLIGIBILITY MEASUREMENTS? |
|
Definition
1. %ALcons- Articulation Loss of Consonants
2. Speech Transmission Index
3. Clarity Ratio-Energy Time Curve
C50-Speech
C80-Concert
Initial Time Delay Gap |
|
|
Term
| •WHAT IS THE NAME USED TO DESCRIBE UNITS OF ABSORPTION? |
|
Definition
|
|
Term
| •DEFINE CRITICAL DISTANCE. |
|
Definition
The distance from the source where the reverberant and direct sound field are equal in level. |
|
|
Term
| •HOW DOES A TEMPERATURE LAPSE AFFECT SOUND? |
|
Definition
Sound bends toward the colder air.
The sound ray paths curve upward. During the day, the air temperature is warm close to the ground. This temperature decreases as you increase height. The sound bends toward the sky. |
|
|
Term
| •HOW DOES A TEMPERATURE INVERSION AFFECT SOUND? |
|
Definition
Sound bends toward the colder air.
During the night. The air temperature is lower closest to the ground and increases with height. The sound bends toward the ground. |
|
|
Term
| •WHAT IS PURPOSE OF “A WEIGHTING” ON AN SPL METER? |
|
Definition
| This contour is designed to approximate the ear at the 40phon level. This weighting is used to measure ambient sound levels. |
|
|
Term
| •WHAT IS PURPOSE OF “C WEIGHTING” ON AN SPL METER? |
|
Definition
•This contour approximates the ear’s response at very high sound levels.
•Often used to measure traffic noise. |
|
|
Term
| •WHAT IS THE RECOMMENDED SPL METER WEIGHTING? WHY? |
|
Definition
“A” Weighted slow correlates with most standard exposure limitation charts.
•"A" Weighted slow is also recommended because it focuses attention on the frequencies that sound the loudest and are vital for communication. |
|
|
Term
| •NAME SOME COMMONLY USED SPEAKER CABLE CONNECTORS USED BY PROFESSIONAL SOUND COMPANIES (MANUFACTURER AND MODEL). |
|
Definition
• NL-4,8
• EP/AP 4,6,8
• POWER |
|
|
Term
|
•USING A STANDARD WIRE TABLE WE DETERMINE THAT FOR EACH 300METERS/1000FT OF 10 GAUGE WIRE, WE HAVE IW OF RESISTANCE. HOW MUCH RESISTANCE WOULD AN 80METER RUN OF SPEAKER CABLE HAVE?
[image] |
|
Definition
|
|
Term
| •WHAT DOES THE 5% RULE STATE? |
|
Definition
| CABLE RESISTANCE SHOULD NEVER EXCEED 5% OF LOAD RESISTANCE. |
|
|
Term
| •WHAT IS “DAMPING FACTOR”? |
|
Definition
| A numerical indication of how well an amplifier can “control” a loudspeaker’s cone motion. FOLLOW THE 5% RULE! |
|
|
Term
•WHAT WOULD BE THE ELECTRICAL DAMPING FACTOR OF A LOUDSPEAKER WITH A DC VOICE COIL RESISTANCE OF 8Ω, AN AMPLIFIER OUTPUT IMPEDANCE OF .001Ω, AND A TOTAL CABLE RESISTANCE OF .53Ω?
[image] |
|
Definition
|
|
Term
| LIVE AUDIO SYSTEMS ARE OPTIMIZED FOR __________ ___________. |
|
Definition
|
|
Term
| PROGRAM SOURCES VARY IN __________, __________&__________. |
|
Definition
| Voltage, Impedance & Topology (Connectors) |
|
|
Term
| NAME THE 3 TYPES OF PROGRAM SOURCES. |
|
Definition
| Microphone, Instruments, Playback |
|
|
Term
| WHAT IS A MIXER’S MAIN JOB WITH REGARD TO PROGRAM SOURCES? |
|
Definition
| To scale mic level signals to line level (+4dBu) |
|
|
Term
| WHAT ARE 3 MAIN TYPES OF SIGNAL PROCESSING? |
|
Definition
| Filtering, Delay, Dynamics |
|
|
Term
| POST MIXER PROCESSING IS MAINLY ________________ IN NATURE. |
|
Definition
| Technical (as opposed to Artistic) |
|
|
Term
| WHERE DO WE USE “MATCHED” OR “TERMINATED” INTERFACE? |
|
Definition
| Video, Wireless Antenna Systems & Long Transmissions |
|
|
Term
| IN A ___________ AUDIO CIRCUIT, IT IS BENEFICIAL TO HAVE THE LOAD IMPEDANCE ____TIMES THE SOURCE IMPEDANCE TO INSURE EFFICIENT ________TRANSFER FROM DEVICE TO DEVICE. |
|
Definition
|
|
Term
| WHY CAN’T WE “Y” 2 OUTPUTS TO AN INPUT? |
|
Definition
•Outputs will both try to drive each others low impedance causing high current to develop.
•Outputs are low impedance and meant to drive the higher impedance of the input. |
|
|
Term
| LOUDNESS AND POWER RELATE TO THE _____ OF THE SIGNAL. |
|
Definition
|
|
Term
| CLIPPING CAUSES _________ __________ WHICH CAUSES THE SIGNAL TO SOUND BAD. |
|
Definition
|
|
Term
| WHY IS MONITORING THE PEAKS OF SIGNAL IMPORTANT? |
|
Definition
| Monitoring peaks can help us avoid loudspeaker damage. |
|
|
Term
| WHY IS MONITORING THE RMS OF SIGNAL IMPORTANT? |
|
Definition
| Monitoring RMS can help us avoid loudspeaker damage. |
|
|
Term
| DEFINE METER INTEGRATION TIME. |
|
Definition
The time it takes for a meter to respond to a signal.
AKA Meter Ballistics. |
|
|
Term
| WHAT IS THE DIFFERENCE BETWEEN A “QUASI” AND A “TRUE” PPM? |
|
Definition
•A quasi-ppm has a 5-10ms integration time causing it to not display short-term peaks. A quasi-PPM will often read 8-10dB lower then a TPPM.
•True ppm (TPPM) has instant ballistics that read out any short term peaks. TPPMs are often used in the recording environment to avoid any instance of distortion. |
|
|
Term
| WHAT IS THE MAIN DRAWBACK OF USING A PPM? |
|
Definition
•A PPM cannot monitor loudness or RMS.
•Loudness and RMS affect hearing safety and potential loudspeaker damage. |
|
|
Term
| 0 DBFS CAN BE REFERENCED TO A ______ OR A ______ WAVE. |
|
Definition
|
|
Term
| WHEN WOULD A TRUE PEAK PROGRAM METER (TPPM) BE USEFUL? |
|
Definition
| •When recording to avoid short term peaks that would cause unwanted harmonic distortion. |
|
|
Term
| WHAT IS THE RESPONSE OR INTEGRATION TIME OF A VU METER? |
|
Definition
|
|
Term
| HOW MANY VOLTS DOES 0VU EQUAL? |
|
Definition
|
|
Term
|
Definition
•The difference between peak and average signal.
•Crest factor in dB=10log(peak/average)
•Heating capacity of the signal
“Area under the curve” |
|
|
Term
| WHAT IS THE CREST FACTOR OF A SINE WAVE? |
|
Definition
|
|
Term
| WHAT IS THE DIFFERENCE BETWEEN AES PINK NOISE AND TRADITIONAL PINK NOISE? |
|
Definition
•AES pink is filtered so that it has 6dBCF.
•Traditional pink noise has a crest factor of 10dB.
•All pink noise is filtered white noise and has equal energy per octave. |
|
|
Term
| WHAT IS THE CREST FACTOR OF TYPICAL MUSIC? |
|
Definition
|
|
Term
|
Definition
| Peak level – Noise Floor. |
|
|
Term
|
Definition
•The result of atoms bumping into each other.
•Electronic Noise. |
|
|
Term
| •WHY ARE WE FORCED TO DEAL WITH SYSTEM GAIN STRUCTURE? |
|
Definition
•There is no standard noise floor level.
•There is no standard peak input/output level. |
|
|
Term
| •HOW MANY VOLTS DOES 0 dBU EQUAL? |
|
Definition
.775V
Derived from old telephone specs based on 600Ω and .001 watt (0dBm) “U” stands for undetermined. |
|
|
Term
•WHAT DEVICES ARE USED TO ADJUST ATTENUATION WHEN SETTING A
SYSTEM’S GAIN STRUCTURE? |
|
Definition
•External pads
•Onboard input/output controls provided they are “before” the pre-amp. |
|
|
Term
| •WHAT IS THE PURPOSE OF A SYSTEM LIMITER? |
|
Definition
| To act as an early warning device that allows you to take measures to protect the system. |
|
|
Term
| •WHAT RATIO SETTING IS BEST FOR A SYSTEM LIMITER? |
|
Definition
|
|
Term
| •WHAT 3 METHODS ARE USED TO DETERMINE CLIP POINTS IN A SYSTEM? |
|
Definition
•Piezo magic,
•Onboard indicators,
•Oscilloscope |
|
|
Term
| •BEFORE PHYSICALLY SETTING GAIN STRUCTURE, WHY DO YOU FIRST RUN SIGNAL THROUGH THE SYSTEM? |
|
Definition
•To check the integrity of the system.
•You must fix grounding, power, and driver issues before attempting to calibrate a system’s gain structure. |
|
|
Term
| •WHY WOULD WE ZERO OUT AN EQ BEFORE ATTEMPTING TO SET GAIN STRUCTURE? |
|
Definition
•Any cuts or boosts will affect the EQ output during calibration.
•Log the existing curve before zeroing to prevent possible hurt feelings. |
|
|
Term
| •CALCULATE THE VOLTAGE SEEN AT AN OUTPUT WITH A METER READING OF 12dBu. |
|
Definition
| 10ˆdb/20 x Reference Volts = Volts 3.08V |
|
|
Term
| •WHAT IS AMPLIFIER INPUT SENSITIVITY? |
|
Definition
| The amount of voltage required at an amplifier's input to produce full rated output. |
|
|
Term
| •WHAT ARE THE TWO COMPONENTS THAT MAKE UP A RADIO WAVE? |
|
Definition
| Magnetic field (“H” Field), Electric field (“E” Field): Determines polarization. |
|
|
Term
|
Definition
| Base unmodulated frequency the TX and RX remain locked to. |
|
|
Term
| •NAME TWO TYPES OF MODULATION? |
|
Definition
|
|
Term
| •WHAT TYPE OF MODULATION IS USED FOR WIRELESS MICROPHONE AND IN EAR–MONITOR SYSTEMS? WHY? |
|
Definition
| Frequency modulation because it has a wider frequency response (50-16kHz) and better dynamic range (90+ dB). |
|
|
Term
•WHAT TWO TYPES OF AUDIO SIGNAL PROCESSING ARE USED IN
TRANSMITTING AND RECEIVING? WHY? |
|
Definition
•Pre/Post emphasis EQ
•Companding |
|
|
Term
| •WHAT DOES TRUE DIVERSITY MEAN? |
|
Definition
| The ability to sample the radio field from 2 or more location and/or the ability to select/combine the resulting signal. |
|
|
Term
| •WHAT DIVERSITY DESIGN IS MOST COMMON? |
|
Definition
| Receiver switching diversity. |
|
|
Term
| •WHAT IS THE MINIMUM SIZE FOR A TRANSMITTING OR RECEIVING ANTENNA? |
|
Definition
| ¼ the size of the wavelength you are transmitting or receiving. |
|
|
Term
| •WHAT IS THE BEST WAY TO MAINTAIN MAXIMUM EFFICIENCY BETWEEN A TRANSMITTING AND RECEIVING ANTENNA? |
|
Definition
| Line of sight between TX and RX. |
|
|
Term
| •NAME 4 TYPES OF COMMONLY USED ANTENNA DESIGNS. |
|
Definition
•Ground Plane
•Whip
•Yagi
•Logarithmic periodic dipole array (LPDA)
•Helical
•Circularly Polarized |
|
|
Term
| •WHAT ARE THE TWO TYPES OF ANTENNA DISTRIBUTION AND WHEN WOULD WE USE THEM? |
|
Definition
| Passive (up to 2), Active (more than 2). |
|
|
Term
| •WHAT CAUSES “DROP OUT”, “NOISE UP” AND “HITS”? |
|
Definition
•Obstructions
•Dead or dying Batteries
•Multi-path Effects |
|
|
Term
| •WHAT IS THE PURPOSE OF THE SQUELCH CIRCUIT? |
|
Definition
| To mute the audio output of the receiver when RF signal level falls below a set threshold. |
|
|
Term
| •WHICH FREQUENCY BAND HAS its TRANSMITTER POWER LIMITER TO 50mW? |
|
Definition
| VHF (Very High Frequency) |
|
|
Term
| •WHICH FREQUENCY BAND HAS its TRANSMITTER POWER LIMITER TO 250mW? |
|
Definition
| UHF (Ultra High Frequency) 300-3GHz. |
|
|
Term
| •WHICH FREQUENCY BAND IS ILLEGAL TO USE AS OF JUNE 2010? |
|
Definition
|
|
Term
| •TWO CHANNELS HAVE BEEN ALLOCATED IN EVERY MAJOR CITY MARKET FOR WIRELESS USE. WHERE ARE THEY LOCATED? |
|
Definition
| UHF – TV Channel 37: the first open channel that is above and the first open channel that is below. |
|
|
Term
| Name the three parts of the fiber optic cable. |
|
Definition
|
|
Term
| What is the difference between multimode and single mode fiber? |
|
Definition
| One has short distance and lower bandwidth. The other has long distance and unlimited bandwidth. |
|
|
Term
| What is the difference between tight and loose buffer cable? |
|
Definition
One is light weight, easy to terminate, and for indoor use.
The other has greater resistance to temperature changes, used outdoors, and harder to terminate. |
|
|
Term
| Name the four advantages of using fiber over copper cables. |
|
Definition
| Difficult to tap, Immune to EMI, Longer Distances, Greater Information Capacity, No crosstalk. |
|
|
Term
| Name two methods used to splice fiber cables. |
|
Definition
|
|
Term
| What are the two most common connectors used for termination of fiber? |
|
Definition
|
|
Term
| Name three fiber optic light sources used in fiber optics. |
|
Definition
|
|
Term
| What does VCSEL stand for? |
|
Definition
| Vertical Cavity Surface Emitting Laser |
|
|
Term
| Name some unique benefits ear monitors provide. |
|
Definition
| Mobility, safer on ears, stage sight lines, less stage volume, less chance for feedback, better sounding mix, quick set-up and strike, less bulk. |
|
|
Term
| Give some application examples of an in ear monitor system. |
|
Definition
| Theater, broadcast, live performance, studio monitoring. |
|
|
Term
| A basic wireless in-ear monitor system consists of… |
|
Definition
| Console → multi-band peak limiter/compressor → transmitter → receiver → ear molds. |
|
|
Term
| Why is it important to drive an in-ear monitor system transmitter properly? |
|
Definition
•If the input is too low, you will have to operate the receiver volume at too high a level leading to excessive noise.
•If the input is too high, you will cause over-modulation distortion. There is also a danger of bleed into adjacent radio channels. |
|
|
Term
| Why is a multi-band peak limiter necessary at the transmitter input? |
|
Definition
| To prevent hearing damage due to a level spike or feedback loop, and to enhance the mix. |
|
|
Term
| What bank positions typically use hardwire in-ear mix as opposed to a wireless one? |
|
Definition
|
|
Term
| What is the first thing you need to do to obtain custom ear molds? |
|
Definition
| Go to a hearing aid center or an audiologist and have impressions taken of your ears. |
|
|
Term
| How can an ambient microphone fed into a musician’s in ear monitor mix help the musician? |
|
Definition
•It helps the musicians hear the crowd response.
•It helps with localization when using isolating molds.
•Allows communication on stage. |
|
|
Term
| Explain why a monitor wedge would be used in combination with an in-ear mix. |
|
Definition
|
|
Term
| What is multi-band limiting? |
|
Definition
| It allows separate limiter control over multiple frequency bands. |
|
|
Term
| Name some techniques other than a wedge that are used to enhance the low end of an in-ear mix. |
|
Definition
•Bass "shaker”
•Side fill subs. |
|
|
Term
|
Definition
| Has a short distance and lower bandwidth. |
|
|
Term
| What is single mode fiber? |
|
Definition
| Has long distance and unlimited bandwidth. |
|
|
Term
| What is tight buffer cable? |
|
Definition
| It is light weight, easy to terminate, for indoor use. |
|
|
Term
| What is loose buffer cable? |
|
Definition
| It has a greater resistance to temperature changes, used outdoors, and harder to terminate. |
|
|
Term
| What advantage does the focal point of an array offer? |
|
Definition
| It helps us determine accurate splay angles. The point at which a listener in the “far field” perceives the sound originating. |
|
|
Term
| What are the two primary factors that affect array performance? |
|
Definition
•Coverage angle of an individual speaker.
•Splay angle between adjacent speakers. |
|
|
Term
| What are four basic types of point source arrays? |
|
Definition
•Point Source Wide (splayed)
•Point Source Narrow (Tight)
•Point Destination (Split Xfire)
•Exploded (Split Point Source) |
|
|
Term
| What type of array is recommended for front fill applications? |
|
Definition
•Split Parallel
•Flown Center Cluster
•Onstage Fill |
|
|
Term
| At what point should front fill speakers overlap? |
|
Definition
| 6dB down point (2k) at the first row of listeners. |
|
|
Term
| Where/Why are delay fills used? |
|
Definition
| •Outdoors: to overcome the natural attenuation of high frequencies by the air. •Indoors: To increase the direct to reverberant sound ratio |
|
|
Term
| What is a fictitious source? |
|
Definition
| A point used for the time reference of a system. All speaker systems are delayed to this point. |
|
|
Term
| Name some important considerations when using delay towers. |
|
Definition
| To maintain the same axis as the mains. Many small zones are more effective than 1 big one. Don’t crank them up, make them transparent to the mains (unless a new visual reference is established). Pursue stereo at your own risk. |
|
|
Term
| What is the difference in level between half space and quarter space? |
|
Definition
| 10log4 - 10log2 = 6 - 3 = 3dB |
|
|
Term
| What is so important about a horn’s cut off frequency? |
|
Definition
| The lowest frequency a horn can safely produce and maintain acoustic loading. |
|
|
Term
| Explain the standard power up and power down sequence for a pro audio system. |
|
Definition
•Amps on last
•Amps off first |
|
|
Term
| Name three methods to test a loudspeaker driver. |
|
Definition
•Battery (Cone Drivers Only)
•Sine Wave Sweep Station
•DMM |
|
|
Term
| Name the two modes used with a DMM when testing loudspeakers. |
|
Definition
|
|
Term
| Name three benefits of using Ferrofluid. |
|
Definition
•Heat dissipation (power handling)
•Coil Centering
•Mechanical Damping (fidelity) |
|
|
Term
| Name three types of material used to make compression driver diaphragms. |
|
Definition
•Beryllium
•Titanium
•Aluminum |
|
|
Term
| Name two benefits of adopting a thorough labeling scheme for your audio system. |
|
Definition
•Helps with quick set-up
•Helps with identification of bad components |
|
|
Term
| Networks can be classified using 2 properties. Name them. |
|
Definition
|
|
Term
| Name the three common network topologies. |
|
Definition
•The Ring
•The Star
•The Bus |
|
|
Term
| What is the difference between baseband and broadband transmission? |
|
Definition
•One send binary values directly as pulses of voltage of current.
•The other is a multiple channel baseband. |
|
|
Term
| What is the difference between single ended and differential? |
|
Definition
•One is Unbalanced: all data lines share one ground
•The other is Balanced |
|
|
Term
| What is asynchronous transmission? |
|
Definition
| A communications strategy that uses a start and stop bit to indicate the beginning and end of a transmission. |
|
|
Term
| What is synchronous transmission? |
|
Definition
| A communications strategy that uses timing to control transmissions. |
|
|
Term
| What is isochronous transmission? |
|
Definition
| Means time sensitive. Its operation is dependent on constant time intervals. |
|
|
Term
| What is cobranet technology? |
|
Definition
| A combination of hardware, network protocol, and firmware that allows us to send audio over Ethernet in real time. |
|
|
Term
| How many channels of digital audio can a system using cobranet carry on a 100Base T network? |
|
Definition
|
|
Term
| What is the job of a “conductor” in a network using cobranet? |
|
Definition
|
|
Term
| What does “10/100base T” tell you about a network? |
|
Definition
•1/100 = Speed
•Base = Signal type.
•T = Cabling |
|
|
Term
| What is data terminal equipment? |
|
Definition
| Anything that produces or consumes data on a network. |
|
|
Term
| Give two examples of data communication equipment. |
|
Definition
•Hub
•Switch Router
•Network interface card |
|
|
Term
|
Definition
| Specifies a common set of rules and signals the device on the network uses to communicate. |
|
|
Term
| What three things does OSI allow us to do concerning protocols? |
|
Definition
•Provides a common way to analyze protocols
•Allows one to compare protocols
•Helps troubleshoot network problems. |
|
|
Term
|
Definition
| It is 6 bytes long, often noted in hexadecimal. Cannot be changed it is burned into hardware. No two are the same. It is used to identify a node on a network. |
|
|
Term
| What layer of OSI does an IP address operate? |
|
Definition
|
|
Term
| What are the two ways an IP address can be assigned to a node on a network? |
|
Definition
|
|
Term
| Which OSI layer handles port access? |
|
Definition
| Layer 4 (Transport Layer). |
|
|
Term
| What is a Baseband transmission? |
|
Definition
| It sends binary values directly as pulses of voltage or current. |
|
|
Term
| What is a broadband transmission? |
|
Definition
| This is a multiple channel baseband transmission. |
|
|
Term
| What does "single ended" mean? |
|
Definition
| Unbalanced: all data lines share one ground. |
|
|
Term
| What does "differential" mean? |
|
Definition
| This means that data lines are balanced. |
|
|
Term
| What does “10/100” tell you about a network? |
|
Definition
|
|
Term
| What does “T” tell you about a network? |
|
Definition
|
|
Term
| What does the "base" tell you about a network? |
|
Definition
|
|
