| What is another common name for a constant voltage system |
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High impedance
Distributed
70 volt |
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| Where are constant voltage audio systems commonly used |
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| Commercial Establishments |
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| Why is a Transformer Required at each speaker in a distributed system |
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Commercial Power distrobution
Step down Voltage |
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| What are three voltages that are commonly used for constant voltage audio systems |
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100 volts
70.7 volts
25 volts |
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| How are speakers rated in distribution systems |
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| How many Speakers can be connected to an amp in a constant voltage system |
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As many as you want as long as you do not exceed amp capacity
also keep an eye on ohm load impedance |
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| Besides the power used by the speaker what are two other factors to concider when concering power loss |
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Transformer Insertion loss *(TIL)*
loss due to cable |
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| What is the industry rule of thumb used when figureing required amp output wattage for a constant voltage system |
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Total tap wattage + 20% amp wattage or total tap wattage x 1.2 = amp wattage
number of speakers
zones and control
wire requireement
Amp Requirement |
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| Why should you turn on amps after you turn on all other electronic equipment in a sound system |
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| So you dont get a pop in the system |
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| Name and explain some methods used to test a driver |
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9 volt battery
DMM ohms and continutity
Sine wave sweeper |
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| Name 3 benifits of using ferrofluid |
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Heat dicipation
Keep coil centered in the gap
Extra Mechanical damping |
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| Name 3 types of material used to make compression driver diaphrams |
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Alluminum
Titanium
Beryllium |
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| Peack level minus noise floor |
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| Why are we forced to deal with a systems gain structure |
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| because there is no standard peak level or noise floor |
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| What is the benefit of laying out a systems gain structure on paper |
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| Helps you make intelligent design and purpose decisions |
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| How many volts does 0dbu equal |
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| What ways are attenuation ajusted to set a systems gain structure |
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| How do we deal with aligning the crossover ouputs with each amplifier input it feeds |
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| Each must be delt with as a seperate gain structure branch |
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| What is the purpose of a system limiter |
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| early warning device that allows you to protect your system |
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| What ratio setting is best for a system limiter |
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| What four methods are used to determine clip points in a system |
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on board lights
oscilliscope
Piezo tweeder
DMM |
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| When using an oscilliscope to find clip points how do uou connect the positive and negative leads of the scope to the audio lines |
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Tie low to ground
Pin 3 to pin 1
positive to negative |
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When physicaly setting gain structure
why do you first run signal through the system |
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| see if it works to check systems integrity |
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| Why would we zero out an eq before attemting to set gain structure |
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| Any cuts or boosts will affect callibration |
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| In a typical audio circuit it is beneficial to have the load impedance 10 times the source imp to insure efficient voltage transfer from device to device |
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| What is amplifier sensitivity |
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| The amount of voltage required at input to produce full rate output |
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