What is another common name for a constant voltage system
High impedance
70 volt
Where are constant voltage audio systems commonly used
Commercial Establishments
Why is a Transformer Required at each speaker in a distributed system
Commercial Power distrobution
Step down Voltage
What are three voltages that are commonly used for constant voltage audio systems
100 volts
70.7 volts
25 volts
How are speakers rated in distribution systems
DBspl per wattage tap
How many Speakers can be connected to an amp in a constant voltage system
As many as you want as long as you do not exceed amp capacity
also keep an eye on ohm load impedance
Besides the power used by the speaker what are two other factors to concider when concering power loss
Transformer Insertion loss *(TIL)*
loss due to cable
What is the industry rule of thumb used when figureing required amp output wattage for a constant voltage system
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
Why should you turn on amps after you turn on all other electronic equipment in a sound system
So you dont get a pop in the system
Name and explain some methods used to test a driver
9 volt battery
DMM ohms and continutity
Sine wave sweeper
Name 3 benifits of using ferrofluid
Heat dicipation
Keep coil centered in the gap
Extra Mechanical damping
Name 3 types of material used to make compression driver diaphrams
What is dynamic range
Peack level minus noise floor
What is thermal noise
Electric noise
Why are we forced to deal with a systems gain structure
because there is no standard peak level or noise floor
What is the benefit of laying out a systems gain structure on paper
Helps you make intelligent design and purpose decisions
How many volts does 0dbu equal
What ways are attenuation ajusted to set a systems gain structure
on board and external
How do we deal with aligning the crossover ouputs with each amplifier input it feeds
Each must be delt with as a seperate gain structure branch
What is the purpose of a system limiter
early warning device that allows you to protect your system
What ratio setting is best for a system limiter
8:1 or greater
What four methods are used to determine clip points in a system
on board lights
Piezo tweeder
When using an oscilliscope to find clip points how do uou connect the positive and negative leads of the scope to the audio lines
Tie low to ground
Pin 3 to pin 1
positive to negative
When physicaly setting gain structure
why do you first run signal through the system
see if it works to check systems integrity
Why would we zero out an eq before attemting to set gain structure
Any cuts or boosts will affect callibration
Audio montage
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
What is amplifier sensitivity
The amount of voltage required at input to produce full rate output