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355 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Acoustical Studies I
1. What are the three distinct forms of particle motion? |
Cylindrical Wave
Transverse Wave Longitudinal Wave |
C________ Wave
T________ Wave L________ Wave |
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2. How do you calculate the velocity of sound knowing the temperature?
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C = sq rtYPs/P
Y = ratio of specific heats, 1.4 oz for air. Ps = equilibrium gas pressure P = density of air, 1.2 number |
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3. How does temperature affect the velocity of sound?
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Speed of sound increases as the temperature rises, and decreases as temperature lowers.
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4. What is a wavelength?
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Physical distance of a sound wave, peak to peak, trough to trough
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5. How do you calculate wavelength?
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X = 1130(FPS)/Hz
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6. How can you reverse polarity?
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Take all frequencies and flip them 180 degrees
Swap pins 2 & 3 Swap + & - at speaker |
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7. Describe phase?
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Frequency dependant time delay
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8. How do you calculate octave relationships?
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Doubling (100, 200, 400)
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9. How do you calculate harmonics?
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Multipliers – Fundamental
500 Hz x harmonic you are looking for (1, 2, 3, 4, etc.) |
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10. How do you calculate a range of octaves?
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2^n = FH/FL
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Intro to Measurement systems
1. What are the main reasons for sound system measurement? |
Maintenance
Legal Issues Artistic |
M________
L____ I____ A________ |
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2. What 5 basic test signals are used for sound system measurement?
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White Noise, Pink Noise, Shaped Noise (Filtered Pink Noise), Broadband Pulse (Burst of Pink), Sine Wave, more …
White Noise Pink Noise Shaped Noise Broadband Pulse Sinewaves |
White Noise
Pink Noise S_______ N________ B________ P________ S________ |
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3. What is white noise?
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Equal Energy Per Frequency
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4. What is pink noise?
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Equal Energy Per Octave
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5. What are the 2 most common weighting curves used for SPL meters?
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A and C (or linear) Weighting
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6. What dimension is a real time analyzer missing?
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Time
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7. What is the Fourier transform?
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A mathematical computation that converts an Amplitude vs. Time Graph into an Amplitude vs. Frequency Graph
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8. What measurement systems use FFT’s?
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SIM & SMAART
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9. What does TEF stand for?
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Time
Energy Frequency |
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10. What does MLS stand for?
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Maximum Length Sequence, also a FFT system which is a little more randomized, but still hits all frequencies at the same time.
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Measurement Systems Dimensions
Voltage Examples: Number of Dimensions: Which Dimensions: Number of Ports: |
Voltage
Examples: Volt Meter Number of Dimensions: 1 Which Dimensions: Energy Number of Ports: Single – receives, sends info |
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Current
Examples: Number of Dimensions: Which Dimensions: Number of Ports: |
Current
Examples: Amp Meter Number of Dimensions: 1 Which Dimensions: Energy Number of Ports: Single |
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Resistance
Examples: Number of Dimensions: Which Dimensions: Number of Ports: |
Resistance
Examples: Ohm Meter Number of Dimensions: 1 Which Dimensions: Energy Number of Ports: Dual (sends voltage, determines resistance) |
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Impedance
Examples: Number of Dimensions: Which Dimensions: Number of Ports: |
Impedance
Examples: Impedance Meter Number of Dimensions: 1 or 2 Which Dimensions: Energy, sometimes Frequency Number of Ports: Dual |
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Time Domain Reflectometer
Examples: Number of Dimensions: Which Dimensions: Number of Ports: |
Time Domain Reflectometer
Examples: Time Domain Reflectometer Number of Dimensions: 2 Which Dimensions: Time, Energy Number of Ports: Dual |
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Sound Pressure Level
Examples: Number of Dimensions: Which Dimensions: Number of Ports: |
Sound Pressure Level
Examples: SPL Meter Types of SPL Meters 0 – Laboratories 1 – Engineering 2 – General Purpose (what we use) 3 – Special Purpose (NASA, etc…) Number of Dimensions: 1 Which Dimensions: Energy Number of Ports: Single |
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Real Time Analyzers (RTA)
Examples: Number of Dimensions: Which Dimensions: Number of Ports: |
Real Time Analyzers (RTA)
Examples: RTA Number of Dimensions: 2 Which Dimensions: Frequency & Energy Number of Ports: Basically a 1-port system but has 2 single ports |
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SMAART
Examples: Number of Dimensions: Which Dimensions: Number of Ports: |
SMAART
Examples: SIM & SMAART Number of Dimensions: 3 Which Dimensions: Energy, Time, & Frequency Number of Ports: 2 |
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TEF
Examples: Number of Dimensions: Which Dimensions: Number of Ports: |
TEF
Examples: TEF – TEF uses Time Domain Spectrometry (TDS) which eliminates outside noise by using a sweeping time wave (good for mic cables, mixing desks, but NOT for loudspeakers) Number of Dimensions: 3 Which Dimensions: Energy, Time, & Frequency Number of Ports: 2 |
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Phase Poppers
Examples: Number of Dimensions: Which Dimensions: Number of Ports: |
Phase Poppers
Examples: Phase Poppers Number of Dimensions: 1 Which Dimensions: Energy Number of Ports: 2 |
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Sim II/Design Reference Study I
1. What is an electronic crossover point? |
Processor based crossover - Where the low and high output of the processor crosses over.
Suggested reading pgs. 66 – 68, 12 – 15, 30 – 35 |
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2. What is an acoustic crossover point?
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The frequency at which the drivers have equal amplitude response levels. (When both drivers are driven at the same amplitude)
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3. What is amplitude correction?
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A boost in certain areas of the frequency response to correct for inefficiencies of a speaker cabinet.
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4. What is phase correction?
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Delaying certain frequencies to allow all frequencies to arrive at the same point at the same time – Time Alignment
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5. How do amplifier spec sheets denote voltage gain?
Define: X-Multiplier Input Sensitivity |
dBvg (dB Voltage Gain)
X-Multiplier – ratio of output voltage vs. input Input Sensitivity – Input voltage required to achieve full voltage swing at the output |
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6. What is power amplifier voltage gain?
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Ratio of input to output voltage
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7. What mathematical formulas do you use to calculate amplifier voltage gain?
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dBVg = 20 log Vout/Vin or (if needed) dBVg = 20 log V mult
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8. What mathematical formula do you use to calculate maximum output voltage?
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Mov = sqrt watts x 8
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9. How do you match amplifier voltage gains?
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Adjustable Potentiometers
DIP Switches Front Panel Attenuators |
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10. What are some of the side effects of reducing the low frequency amplifier gain?
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Page 34
Decrease low frequency buildup Shifts acoustic crossover domain frequency Possible phase misalignment at the crossover region Requires the high driver to carry more of the medium frequency power response Misalign phase relationship Alter directional response at crossover |
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EASE Overview 1
1. EASE was developed by? |
Wolfgang Ahnert
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2. What other types of room input methods are there other than vertex by vertex?
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Insert 3D shapes
Extrude Load Prototypes |
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3. Exterior surfaces are what color?
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White
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4. Interior surfaces are what color?
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Yellow
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5. What is the hot key used to save and apply?
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F6
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6. Why are most rooms modeled in the negative Y-axis?
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It’s the way the speakers are facing when inserted (they are placed facing the negative y-axis)
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7. What is the command for cutting a face into two faces?
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Fixed Cut
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8. What is the hotkey to delete unattached vertices?
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Control + Shift + F12
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9. When adding floor to ceiling columns in a room, you must?
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“Is Coat Of”, then face number
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10. What are some of the prototypes available?
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Stadium
Theatre Basilica Gothic Dome Church Sporting Hall Auditory Shell Opera |
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SIM II/Lab 2.0 Overview
1. What applications is the SIM II V2.0 lab used for? |
Standalone measurement and research.
Read pg. 70, 77, & 208 |
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2. What are the status panels?
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Information windows at the bottom of the screens
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3. What are the 2 windows in spectrum mode?
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Reference & Measurement; the dimensions are amplitude vs frequency
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4. What are the 2 windows in delay finder mode?
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Delay Time
Dimensions are relative amplitude vs time Bottom window is a 10x magnification of the delay |
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5. What are the 3 traces in the frequency response screen?
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S/N or Coh (Signal to Noise or Coherance)
Frequency Response Phase |
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6. What 2 choices under the setup menu-reference channel are you provided with?
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Generator & Input
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7. What 2 choices under the setup menu-measurement channel are you provided with?
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Output & Mic
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8. What is the hot key to turn the generator on?
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Alt + G (F1 is off)
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9. Which frequency is typically used for measuring harmonic distortion?
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1K
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10. What is the hot key for the auto delay in the delay finder mode?
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F3
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SIM II/Design Reference Study II
1. What advantages does a parametric EQ have compared to a graphic EQ? |
Adjustable Bandwidth
Adjustable Center Frequency |
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2. What is complimentary equalization?
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It is the inverse of the problem, matching in gain, center frequency and bandwidth.
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3. What is error in center frequency?
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When the problem and correction do not match in center frequency.
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4. What is error in bandwidth?
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When the problem and correction do not match in bandwidth.
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5. What is comb filtering?
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Two signals arriving at different times near equal amplitude.
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6. What are the two independent factors that determine the magnitude and frequency response of comb filtering?
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Time and level offset
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7. How do you calculate for comb filtering?
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Take the time difference between the 2 signals arriving and convert them into seconds from milliseconds (move the decimal point 2 places)
F = 1/t (time in seconds) for spacing then divide by 2 for the 1st null |
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8. Why is it called comb filtering?
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On a linear scale, it looks like the bristles of a comb.
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9. What actions could you take to reduce comb filtering?
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Absorption
Level Offset Delays Noise Gates Hi-pass Filters |
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10. Why are graphic equalizers blamed for poor results when trying to correct comb filtering?
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It is a time problem; you cannot correct time problems with frequency.
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SIM II 2.3S Overview I
1. What applications is SIM II 2.3S used for? |
Recording Studios & Stereo Sound Systems
Read pgs. 79 – 80, 209 |
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2. How do you patch for the SIM II 2.3 S?
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Meyer Sound
Design Reference Pg. 80 |
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3. What are the colors of the different frequency response types?
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Red – Coherence or S/N
Blue – Result Green – Inverse EQ (1/EQ) White – Room + Speaker Orange – Microphone |
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4. What is procedure menu – pretest used for?
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Checks continuity of the system patching
EQ channels Branches/Speakers Mic |
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5. What is procedure menu – show used for?
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Generator is disabled
Branch muting is disabled Procedure menu is disabled Except for post process & quit |
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6. What is procedure menu – post process used for?
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It allows you to look at the information but you cannot change anything.
Read Only Memory (ROM) |
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7. What is the inverted EQ?
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It is an upside down EQ
A cut looks like a boost |
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8. How does the feedback finder work?
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Peak hold RTA
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9. How many traces are you able to see at one time using the SIM II 2.3S?
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6
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10. How many memory groups are in each branch?
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8
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SIM II 2.3S Overview II
1. What are the hot keys for the master gain? |
Shift + F1
Shift + F2 |
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2. What are the hot keys for the gain output?
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There are none
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3. What are the keys for the mic gain?
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Shift + F5
Shift + F6 |
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4. What are the 7 steps to analyze a stereo system?
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The sheet is included in our handouts titled “Steps to Analyze a Stereo System”
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5. Where is the primary mic placement?
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+ or - 10 degrees on axis & center of the listening area
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6. Where is the secondary mic placement?
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Anywhere in the listening area
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7. Why does automatic equalization not work?
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It is blind, it does not know where it is or what it is measuring
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8. What are the initial EQ considerations in studios?
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Sweet spot must be wide enough for both ears
Pay attention to s/n or coherence Don’t worry so much about high Q problems |
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9. How do you compare a left speaker response against a right speaker response?
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Using branch
Compare |
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10. What is procedure: Combined Systems?
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Checks to see if the different branches play well together
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Design Reference Study 3
1. What are the effects of speaker interactions? |
Coupling
Combing Combining Echo Isolation Reverberation Pgs. 96 – 97 |
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2. What are the 2 factors of speaker interactions?
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Time & Level Offset
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3. What are the 7 basic types of speaker arrays?
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Point Source Narrow
Point Source Wide Parallel Crossfire Split Point Source Split Parallel Split Crossfire (Point Destination) Pg. 98 |
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4. What differences are noticeable between tight pack and wide pack arrays?
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The rears of the speaker cabinets are touching and the fronts are splayed apart.
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5. What are the different vertical arrays?
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Long Throw Narrow
Long Throw Optimized Wide Angle Optimized Parallel Crossfire Pg. 118 |
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6. How do reflections differ from speaker interactions?
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They don’t, the same mechanisms are at work.
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7. What are the 4 types of reflections?
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Grazing – Split Point Source
Parallel – Split Parallel Rear Wall – Monitor Sidefill Corner – Split Crossfire (Point Destination) |
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8. Which reflections is the most favored?
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Grazing
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9. Which reflection is the most common?
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Parallel
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10. What are equal level contours for speakers?
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The picture Mike drew Simple Radial Arc Coverage, he erased the original lines and connected the dB points that are the same.
Pg. 138 |
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SMAART Live Overview
1. Who was the person who developed SMAART? |
Sam Berkow
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2. Who markets SMAART Live now?
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EAW
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3. What type of sound interface do you need to use SMAART?
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Stereo line in and a line out
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4. What external hardware is needed for SMAART Live?
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Measurement Mic
Mixer Cables and Adapters Delay Unit Microphone Calibrator and/or a SPL Meter |
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5. What is the spectrograph?
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Fish Finder or a 3D Waterfall
Shows all 3 dimensions: time, amplitude, and frequency at the same time, and is also a function of SMAART |
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6. What is fixed point per octave?
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1/24th octave resolution for your FFT’s (Full Fourier Transform)
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7. What are the different generator settings available in SMAART?
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Pink Noise
Sine Wave Dual Sine File Loop Pink Sync Red Sync Pink Sweep Red Sweep |
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8. What do the reference registers do?
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Memory Storage Areas
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9. How do you show harmonics in SMAART?
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Set your marker then Control H
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10. What is the external device menu used for?
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Set up SMAART to control certain digital devices
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Acoustics Studies 2
1. What is reverberation? |
The sound that lingers in a room after it has been turned off.
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2. What is the ITG?
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Initial Time Gap
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3. Who was Wallace C. Sabine?
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Founder of the Science of Architectural Acoustics and developed the RT 60 formula.
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4. What is RT60?
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The amount of time it takes sound to decay by 60dB
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5. What is Sabine’s classic equation for RT60?
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RT 60 = .049V/Sa (a has line over top of it)
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6. What is the formula to calculate the volume of a room?
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Volume = Length x Width x Height
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7. How do you calculate for S (Total Boundary Surface, or Surface Area)?
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Multiply each surface by its two dimensions (L x W) then add them all together.
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8. What is the formula to calculate the average absorption coefficient of a room?
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a (with a line over it) = S1a1+S2A2+S3A3…SnAn/S
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9. What changes are made to the classic Sabine equation, when calculating for the absorption of air?
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Add +4mV to the denominator of the Sabine Equation, RT60 = 0.049V/Sa+4mV
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10. What is Fitzroy’s equation?
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We don’t need to know this
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Architectural Noise Control
1. What does HVAC stand for? |
Heating Ventilation Air Conditioning
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2. The Male carrier wave is between ____ and ____ frequencies?
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200Hz – 350Hz
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3. What is normal in presence of noise?
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Involuntarily raise your voices above the noise level
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4. What does NCB stand for?
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Balanced Noise Criteria
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5. Who was the person that developed the NCB chart?
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Dr. Leo Beranek
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6. What is the recommended NCB rating for a classroom?
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30 – 40
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7. What is transmission loss?
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The loss of sound pressure through various materials
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8. In residential construction, what is a common interior wall made of?
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2x4’s
16” on center ½” drywall on both sides |
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9. How many layers of drywall will provide the greatest value for transmission loss?
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2
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Ease Overview 2
1. Which module shows the 3D Mapping? |
Eyes
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2. What is the symbol used for the Acoustic Probe?
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X, Y, Z Axis
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3. Which two frequencies are used for calculating RASTI?
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500Hz & 2kHz
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4. What does RASTI stand for?
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Rapid Articulation Speech Transmission Index
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5. What does %ALcons stand for?
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Percentage of Articulation Loss of Consonants
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6. In EASE, what does the C stand for?
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Clarity
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7. What does the C7 show?
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Direct to Reverberant (d/r) Ratio
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8. What does the C50 show?
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Speech Intelligibility
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9. What does the C80 show?
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Music Intelligibility
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10. What is the module that demonstrates sound transmission and reflections being scattered in a room, showing the loss of SPL, orders of reflections and propagation time of signals, that module is named?
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Ray Tracing
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SMAART Acoustic Tools
1. What are the two modules that are included in SMAART Acoustic Tools? |
a
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2. What are the four graphs that are available in the Analysis module?
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a
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3. Acoustic tools will not let you do any frequency measurements until you do what?
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a
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4. In the time slice graph, what does the Rainbow button do?
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a
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5. What does the Power Spectrum show?
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a
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6. What are the two methods that Acoustic Tools uses to make impulse measurements?
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a
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7. In the Intelligibility module, what are the three markers and where should they be set?
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a
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8. What is the Intelligibility Graph used for?
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a
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9. Name the Intelligibility measurements that Acoustic Tools can make.
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a
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10. How do you find %ALcons measurements?
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a
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5.1 Calibration Overview
1. What acoustical help can “floating” an absorption panel do instead of mounting it? |
It will absorb more low frequencies, not just mids and highs.
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2. Most home theaters should have an RT60 of ____ seconds from 200Hz to 2kHz.
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Between .2 - .4 seconds
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3. The center speaker should not be more than ____ feet from the height of the left/right.
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+ or - 2 feet
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4. What two types of speakers discussed are used for rear surround sound?
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Dipole
Direct Radiating |
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5. Rear surround speakers should be at a height of?
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At least 6 feet
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6. What is a good way to determine the subwoofer placement to reduce room modes?
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Using an RTA at the critical listening area, move the sub on a low cart across the front of the room, when you have the smoothest low frequency content that is the location, not where there is a boost of frequencies that is possibly a room mode.
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7. What should be the range for the loudest sounds of a soundtrack?
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105 – 110 dB (maybe 115)
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8. What should be the range for the quietest background effects of a soundtrack?
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50 – 55 dB
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9. What three companies made the 5.1 audio toolkit DVD?
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Goldline
PMI Dolby |
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10. What help is a multiplexer when doing 5.1 systems?
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It allows multiple microphones to achieve “Spatial-Averaging”
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TEF Overview I
1. Who developed the theory of time delay spectrometry? |
Richard Heyser
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2. Which company first commercially distributed TEF to the industry?
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Crown
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3. Which company currently owns the TEF patent and distribution?
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Goldline
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4. What kind of connectors does TEF have for line input and mic input?
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2 BNC’s
2 XLR’s |
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5. What kind of cable connections will TEF do to the host computer?
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Serial
Parallel USB/Parallel (Adapter) |
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6. What does TEF stand for?
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Time Energy Frequency
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7. What dimensions are in an ETC curve?
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Amplitude
Time |
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8. The TEF system gathers it’s data in which domain?
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Frequency
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9. It takes ________ to measure time and it takes ________ to measure frequency.
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Frequency, Time
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10. What voltage should you not exceed when doing electrical measurements?
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1.7
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TEF Overview II
1. What is the formula to calculate the time window? |
Bandwidth/Sweep Rate
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2. How do you calculate the distance sound travels?
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d = c x t (distance = speed of sound x time)
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3. How do you calculate the amount of time sound travels when you know the distance?
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d/c = t (distance/speed of sound = time)
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4. What is the time/distance window?
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The bubble around the microphone and speaker, that is created by your choice of parameters.
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5. It may be much more convenient to set a ________ and ________ and let the computer set the sweep rate and bandwidth for us.
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Resolution
Sweep Time |
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6. How do you calculate the total distance of a reflection from a speaker to floor to microphone?
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Pythagorean Theorem (a^2 + b^2 = c^2, then c + c)
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7. What kind of calibrator do we use with TEF?
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Larson-Davis CAL 200
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8. Why does TEF use 20μ (pascals) for calibrating the unit?
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It is the threshold of hearing.
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9. What kind of microphone do we use with the TEF?
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Goldline MK-10
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10. How does the Schroeder reverse integration curve calculate it’s data?
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From the right side of the screen back to the direct signal.
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TEF Overview III
1. What is the formula to calculate THD? |
Long equation, we don't need to know
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2. Acoustic distortion affects three psychoacoustics perceptions, which are?
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Spatial Impression
Frequency Response need 1 more will get from Cody |
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3. Which two harmonics seem to do the most damage to the THD?
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3rd & 5th
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4. What is THD+N?
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THD plus N stands for noise
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5. How does harmonic tracking work?
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Like a TDS Measurement, but instead of tracking the fundamental, it tracks the harmonic chosen.
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6. In a 3D waterfall display, you have to set the ____ and ____ time and the amount of ____ to include.
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Start
Stop Steps |
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7. Polar measurements may be transferred for further use to which software?
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EASE
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Name 4 of the 5 3-D shapes that you can insert into EASE?
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Cuboid, Cylinder, Cupola, Cone, & Pyramids
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SIM Data Analysis
1. What does SIM stand for? |
Source Independent Measurement
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2. Who was primary developer of SIM?
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Bob McCarthy
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3. Where is Meyer Sound?
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Berkley California
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4. 3 versions of SIM II name them?
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2.0 Lab, 2.3 Stereo, 2.3 Multichannel
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5. 2.3 Lab Mode is used for 2 applications name them?
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Stand alone measurement and research
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6. Name the screens (stand alone measurement and research)?
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Delay Finder
Frequency Response Spectrum |
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7. Opens in spectrum name the 2 windows?
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Measurement and Research
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8. How many memory traces can you see?
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1 at a time
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9. How many branches are there?
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16
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10. How many groups in a branch?
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8
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11. How many characters can you see in a notepad?
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First 10
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12. Trace Offset, what are the hot keys?
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The + and – keys and change by 1 dB at a time.
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13. What is trace offset?
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A strictly video function that allows you to center your frequency response on 0 for the purpose of EQing.
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14. What is THD?
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Total Harmonic Distortion
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15. What frequency is used for THD?
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1kHz
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16. Under Reference channel you have generator and what?
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Input
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17. What are the 2 choices under the measurement channel you have output and what?
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Mic
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18. In the overall status panel that says acquiring data what else might it say?
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Data Rejected
Reading Writing Data < Threshold Input Disabled Pause Printing Averaging Complete |
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19. What is the hot key to turn the Generator on?
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Alt G
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20. What is the hot key to turn the Generator off?
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F1
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21. What is the hot key for the gain levels in 2.0?
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There is none
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22. Input Gain hot key 2.0?
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Shift F1 and F2
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23. Output Gain hot key 2.0?
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Shift + F3 or F4
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24. Mic Key hot key 2.0?
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Shift F5 and F6
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25. It will change by 10dB
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Input and Output Gains
Mic Master |
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26. In the delay finder there are 2 windows with no names, but with dimensions what are they?
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Relative Amplitude Vs. Time, 10x magnification of the top screen
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27. F3
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Auto Set Delay for delay finder in SIM
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28. 3 things we can see in delay finder?
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Propagation Delay
Indication of polarity Frequency Content Reflections or Second Arrivals |
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29. Frequency Response Screen, what are the dimensions of the upper window?
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Relative Amplitude Vs. Frequency
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30. The bottom window of the Frequency Response Screen?
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Degrees Vs. Frequency
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31. What are the 4 words for phase?
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Frequency Dependant Time Delay
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32. What is Coherence?
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The amount of understanding the SIM machine has from the signal it sent out to the signal coming back to the machine.
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33. What is a frequency response?
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The difference between the reference and measurement
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34. Phase, angled to the left, right, straight up and down?
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Left - Lagging
Right - Leading Straight Up and Down - Wrapping |
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35. What are the holes (Frequency Response) called?
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Blanking
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36. How do we get rid of blanking?
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Averaging and Smoothing
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37. How many measurements should we do for electronic measurements?
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2 – 4
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38. How many measurements for speakers and rooms?
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8 – 16 depending
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39. Smoothing, what are our choices?
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1/3, 1/6, 1/24 (off, no smoothing)
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40. 2.3 S is used for 2 applications what are they?
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Recording Studios and Stereo Sound Systems
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41. New different menu in 2.3 S
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The Procedure
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42. Why don’t 2.3S have Reference and Measurement?
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We have EQ in and EQ out and Mic, so we have EQ in Vs EQ out, also EQ out Vs Mic, and Room + Speaker so it isn't just Reference and Measurement.
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43. What is the hot key for the input gain 2.3S?
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Shift F1 and F2
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44. Output Gain hot key 2.3S?
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There is none
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45. Shift F5 and F6 do what 2.3S?
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Either output or mic gain (probably mic)
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46. In pretest what is it about and what do we check?
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Checks continuity to make sure everything is patched correctly (EQ patching, Mic, and the Branches (Branch 1 is left and Branch 2 is Right))
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47. What is combined systems about?
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See if the branches “play” well together
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48. What happens in show mode?
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Speaker muting is disabled, you can only go to post process and quit, generator is disabled
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49. Post process is?
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A read only memory, you can’t change anything it only allows you to view
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50. What is the feedback finder?
|
Peak hold RTA
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51. There are 6 traces, what are they?
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(named from top to bottom)
S/N of Result Result S/N of EQ S/N of Room + Speaker Input of EQ Room + Speaker |
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52. What are the colors of Frequency Response in 2.3S?
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Result – blue (EQ in vs mike)
Room + Speaker – White (Eq out vs mike) Inverse EQ – Green (EQ in vs EQ out) S/N – Red |
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53. Primary mic position?
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+ or - 10 degrees off the center axis, in the listening area
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54. Secondary?
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Anywhere in listening area
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55. What kind of mic for measurements?
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Omni
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56. Mic is 90 degrees of source what happens?
|
5k and above rolls off
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57. Certain places you should be cautious of placing a mic, or places you shouldn’t?
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low heights
next to wall or pillar in aisles in exact centers of rooms don’t run through snake system |
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58. What is one thing you have to consider when tuning a studio?
|
Sweet spot must be wide enough for both ears
S/N and/or coherence wide eq not narrow |
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59. Why don’t auto eq work well?
|
It is blind
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a
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a
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Quiz #1
1. Calculate the speed of sound if the temperature is 72 degrees F using the formula(s) provided. (Check Hints for Equations) |
c = 49 sq rt 459.4 + degrees F
= 49 sq rt 459.4 + 72 = 49 sq rt 531.4 = 49 x 23.05 = 1129.45 |
5/9(degreeF – 32) = degree C
c = 49 square root 459.4 + degree F dB = 20log Vout/Vin upside down y = 1130/Hz Hz = 1130/upside down y MOV = square root W x 8 2n =F x h/F x length x = [0.001293H/[1+0.00367 x (degree C)]76]103 c = square root yPs/P |
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2. Describe Phase.
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Frequency Dependent Time Delay
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3. What is the physical distance for the full wavelength of 2 kHz? (Check Hints for Equations)
|
upside down y = 1130/Hz
= 1130/2000 = 0.565 |
5/9(degreeF – 32) = degree C
c = 49 square root 459.4 + degree F dB = 20log Vout/Vin upside down y = 1130/Hz Hz = 1130/upside down y MOV = square root W x 8 2n =F x h/F x length x = [0.001293H/[1+0.00367 x (degree C)]76]103 c = square root yPs/P |
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4. If the note C3 is at 130 Hz, what is the 4th Harmonic of that note? (Check Hints for Equations)
|
= 130 x 4
= 520 Hz |
5/9(degreeF – 32) = degree C
c = 49 square root 459.4 + degree F dB = 20log Vout/Vin upside down y = 1130/Hz Hz = 1130/upside down y MOV = square root W x 8 2n =F x h/F x length x = [0.001293H/[1+0.00367 x (degree C)]76]103 c = square root yPs/P |
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5. What are the Basic Test Signals used for sound system measurement (not just for SIM)?
|
Sine Wave
White Noise Broadband Pulse Pink Noise Shaped Noise |
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6. White Noise is:
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Equal energy per frequency
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7. Pink Noise is:
|
Equal energy per octave
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8. What are the two most commonly used weighting curves for SPL Meters?
|
A & C or Linear
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9. Phase correction is used to?
|
To boost or cut frequencies to correct deficiencies in a cabinet.
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10. Use the following information to answer the question: (Check Hints for Equations)
E. V. P1200 Professional Amplifier 500W A Ch @ 4 Ohms 350W A Ch @ 8 Ohms Input Sensitivity set at 1.55V What is the max output voltage of the above amplifier? |
MOV = sq rt W x 8 (Ohms)
= sq rt 350 x 8 = sq rt 2800 = 52.92 |
5/9(degreeF – 32) = degree C
c = 49 square root 459.4 + degree F dB = 20log Vout/Vin upside down y = 1130/Hz Hz = 1130/upside down y MOV = square root W x 8 2n =F x h/F x length x = [0.001293H/[1+0.00367 x (degree C)]76]103 c = square root yPs/P |
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11. Use the following information to answer the question: (Check Hints for Equations)
E. V. P1200 Professional Amplifier 500W A Ch @ 4 Ohms 350W A Ch @ 8 Ohms Input Sensitivity set at 1.55V What is the voltage gain of the above amplifier? |
dBVG = 20log Vout/Vin (Vout is answer from previous question, and Vin is Input sensitivity)
= 20log 52.92/1.55 =20log 34.14 =30.67 |
5/9(degreeF – 32) = degree C
c = 49 square root 459.4 + degree F dBVG = 20log Vout/Vin upside down y = 1130/Hz Hz = 1130/upside down y MOV = square root W x 8 2n =F x h/F x length x = [0.001293H/[1+0.00367 x (degree C)]76]103 c = square root yPs/P |
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12. Name two side effects that may be seen by reducing the LF amplifier.
|
Crossover point will shift, and possible phase misalignment.
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13. Name ways to model a standard room shape instead of placing vertex by vertex or extruding.
|
Insert 3D shape
Insert Prototype |
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14. What does the F6 key do in EASE?
|
Saves and applies
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15. Why do we model most rooms in the negative-y axis?
|
It is the way the speakers are facing when inserted.
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16. What is the command for cutting one face into two faces?
|
Fixed Cut
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17. Which screen displays the difference between the Reference and Measurement channels in the frequency domain?
|
Frequency Response
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18. Which screen computes and displays the amplitude response of the measured system in the Time Domain?
|
Delay Finder
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19. The SIM II 2.0 Lab software is used primarily for what two applications?
|
Stand alone Measurement & Research
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|
20. In the DATA STATUS PANEL, NOTE will only show how many characters from the NOTEPAD?
|
8
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21. Data Rejected in the Overall Status Panel means?
|
Overload
|
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22. What are the two windows in Spectrum mode and what two dimensions do they display?
|
Reference & Measurement, Amplitude Vs Frequency
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23. In Delay Finder, what is the HotKey for the Autoset Delay?
|
F3
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24. In Delay Finder, what does the lower screen display compared to the upper screen?
|
10 times magnification of the relative amplitude vs time
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25. What does SIM stand for?
|
Source Independent Measurement
|
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26. What does MLS stand for?
|
Maximum Length Sequence
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27. Under the Setup Menu, in Reference Channel, there is a choice of two set-ups, which are?
|
Mic & Generator
|
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a
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a
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a
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a
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a
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a
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Midterm
1. Describe Phase. |
Frequency dependent time delay
|
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|
2. If the note C3 is at 130 Hz, what is the 4th Harmonic of that noise?
|
520 Hz
|
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3. White Noise is:
|
Equal energy per frequency
|
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|
4. Pink Noise is:
|
Equal energy per octave
|
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|
|
5. What is the max output voltage of the above amplifier?
|
a
|
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|
|
6. What is the voltage gain of the above amplifier?
|
a
|
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|
7. Name ways to model a standard room shape instead of placing vertex by vertex or extruding.
|
Insert 3D shape
Insert Prototype |
|
|
|
8. What does the F6 key do in EASE?
|
Saves and applies
|
|
|
|
9. Why do we model most rooms in the negative y-axis?
|
It is the way the speakers are facing when inserted
|
|
|
|
10. What is the command for cutting one face into two faces?
|
Fixed Cut
|
|
|
|
11. Which screen displays the difference between the Reference and Measurement channels in the frequency domain?
|
Frequency Response
|
|
|
|
12. Which screen computes and displays the amplitude response of the measured system in the Time Domain.
|
Delay Finder
|
|
|
|
13. The SIM II 2.0 Lab software is used primarily for what two applications?
|
Stand Alone Measurement and Research
|
|
|
|
14. What are the two windows in Spectrum mode and what two dimensions do they display?
|
Reference & Measurement, Amplitude Vs Frequency
|
|
|
|
15. What advantages does a parametric eq have compared to a graphic eq?
|
Adjustable bandwidth
Adjustable center frequency |
|
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|
16. What are the two independent factors that determine the magnitude and frequency response of comb filtering?
|
Time and level offset
|
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|
|
17. Give two different examples of typical causes of comb filtering. (Not Time and Level Offset)
|
Speaker Interactions
Reflections |
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|
18. Why is it called comb filtering?
|
Viewing on a linear scale looks like the bristles of a comb.
|
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|
19. A speaker is placed in a room that has a sloping floor. This causes a time offset of 4ms between the direct and reflected sound. What would be the comb spacing we would expect to see?
|
f = 1/t
= 1/.004 = 250 |
|
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|
20. Using the comb spacing of the above question, where would the first null be?
|
= 250/2
= 125 |
|
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|
21. SIM 2.3 Stereo Software is used primarily for what two applications?
|
Recording Studios & Stereo Sound Systems
|
|
|
|
22. TRACE COLORS: Name the type of trace that corresponds with each color.
Red |
S/N or Coherance
|
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23. Green
|
Inverse EQ (I/EQ)
|
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24. Blue
|
Result
|
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25. White
|
Room + Speaker
|
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26. Orange
|
EQ
|
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27. Name 2 functions that are disabled when you enter Show Mode.
|
Delay Finder and Generator
|
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|
28. What two menu changes could you make to help prevent blanking?
|
Averaging and Smoothing
|
|
|
|
29. What are the two parameters required for a primary mic position.
|
+/- 10 degrees on axis and center of coverage
|
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|
30. Label all 6 traces in the following 2.3 S Screen. (Name the order from top to bottom of how they appear)
|
S/N or Coherance
Result Signal to Noise of the EQ Signal to Noise of the Room + Speaker Inverse EQ Room + Speaker |
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31. A
|
a
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32. A
|
a
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33. A
|
a
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34. A
|
a
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35. A
|
a
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36. Name the 2 key Factors affecting Speaker Interaction.
|
Time and Level Offset
|
|
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37. Identify Each Array Below.
|
Practice on Midterm or Meyer Sound Pages
|
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38. A
|
a
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39. A
|
a
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40. A
|
a
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41. Name the vertical arrays below
|
Practice on Midterm or in Meyer Sound Pages
|
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42. A
|
a
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43. A
|
a
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44. A
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a
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45. Name the 4 reflections and match them to the “phantom” speaker array they act similar to.
______ Reflection acts as a Split Point Source Array. |
Grazing
|
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46. ______ Reflection acts as a Split Parallel Array.
|
Parallel
|
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|
47. ______ Reflection acts as a Sidefill Monitor Array
|
Rear Wall
|
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|
48. ______ Reflection acts as a Point Destination Array.
|
Corner
|
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|
|
49. Which Reflection of the four is the most favorable one?
|
Grazing
|
|
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|
50. Label the Equal Level Contour Lines.
|
Study Midterm question #50
|
|
|
|
51. What is the hotkey to toggle between live and memory traces?
|
F10
|
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|
|
52. Under the Setup Menu, in Reference Channel, there is a choice of two set-ups, which are?
|
Generator & Input
|
|
|
|
53. Name the type of curtain that is used in the following drawing.
|
Check Midterm Bonus Questions
Eyebrow |
|
|
|
Quiz #2 Questions
1. Name the person that created the SMAART Software? |
Sam Berkow
|
|
|
|
2. What external hardware does SMAART need for Acoustic Analysis of a speaker cabinet? (Not for correction purposes)
|
Measurement Mic
Mixer |
|
|
|
3. What are the Reference Registers?
|
Memory Storage Areas
|
|
|
|
4. What is Fixed Point Per Octave?
|
1/24th Octave Resolution
|
|
|
|
5. ___________ is a topographical view of a waveform, similar to the waterfall display. It is a 3 dimensional plot with frequency on the y-axis, time on the x-axis and amplitude represented by color.
|
Spectrograph
|
|
|
|
6. What are the different generator settings that SMAART has available internally in the software.
|
Pink Noise
Red Sync |
|
|
|
7. What brand of microphone do we use with SMAART for acoustic measurement?
|
Earthworks M30
|
|
|
|
8. What is RT60?
|
The time it takes a signal to decay by 60dB.
|
|
|
|
9. Who was considered the “father of architectural acoustics” and created the RT60 calculation?
|
Wallace Sabine
|
|
|
|
10. What is the formula to calculate the volume of a room?
|
Volume = Length x Width x Height
|
|
|
|
11. Using the classic Sabine Equation, calculate the RT 60 of a room that has a volume of 480,000 ft^3 a Total Surface Area of 42,500 ft^2 and an average absorption coefficient of 0.30 sabins.
|
RT60 = 0.049V/Sa (a has a line over it)
= .049(480,000)ft^3/(42,500ft^2)(0.30) = 23,520ft^3/12,750ft^2 = 1.8 |
|
|
|
12. What do all the variables in this equation stand for?
a (with a line over it) = S1A1+S2A2....+SnAn/S a (with a line over it) = Sn = An = S = |
a (with a line over it) = S1A1+S2A2....+SnAn/S
a (with a line over it) = Average Absorption Coefficient Sn = Surface Area of 1 Side An = Absorption Coefficient of 1 Side S = Total Surface Area |
|
|
|
13. What changes are made to the classic Sabine Equation to include the absorption of air at 2000 Hz and 50% humidity?
RT60 = 0.049V/Sa (with a line over it) |
RT60 = 0.049V/Sa (with a line over it)
You add + 4mV to the denominator RT60 = 0.049V/Sa + 4mV |
|
|
|
14. The Speech carrier wave produced by the vocal cords for male talkers is around _______ to _______.
|
200Hz - 350Hz
|
|
|
|
15. What does NCB stand for?
|
Balanced Noise Criteria
|
|
|
|
16. Plot the NCB rating of a room using the following noise measurements.
|
Study Quiz 2 question #16
|
|
|
|
17. What is the NCB rating for the above?
|
Study Quiz 2 question #18
|
|
|
|
18. If the noise average is 53 dB, and the talker to listener distance is 5m (16’ 5”). What kind of vocal effort would be required for sufficient communication?
|
Quiz 2 Question #?
Raised |
|
|
|
19. What does Normal In Presence of Noise mean?
|
We involuntarily raise our voices because of the noise level.
|
|
|
|
20. Which two frequencies are used for calculating RASTI?
|
500Hz and 2kHz
|
|
|
|
21. What does RASTI stand for?
|
Rapid Articulation Speech Transmission Index
|
|
|
|
22. What does %ALcons stand for?
|
Percentage of Articulation Loss of Consonants
|
|
|
|
23. In EASE for C50 what does the C stand for?
|
Clarity
|
|
|
|
24. What does the C50 show?
|
Speech Intelligibility
|
|
|
|
25. One of the modules in EASE, demonstrates sound transmission and reflections being scattered in a room, showing the loss of SPL, orders of reflections and propagation time of signals, that module is named?
|
Ray Tracing
|
|
