Loud Speakers Flashcards
___ is a generic term used to describe a wide variety of transducers that convert electrical energy into acoustical energy. The term is also commonly used to refer to systems of ___ or more transducers in a single enclosure.
loud speaker
two
In sound reinforcement, what two methods are most common in acoustic transduction?
electrically modulated diaphragm and piezo electrically modulated diaphragm (piezo electric vendors, limited excursion and only work at high frequencies)
Efficient reproduction of low frequency requires that a ___ volume of air be removed. The polarity of the connection terminals may be specified by what two types?
large
color coding or +/- markings
Cone type low frequency driven enclosures are nearly always mounted in ____. If not, the driver would largely cancel itself. Vented enclosures are generally used for ___ systems. The interior of vented enclosures is always lined with __ material to absorb high frequencies within the enclosure.
enclosures
low frequency
absorbent
Cross overs
Low and high frequency devices ___ (can or cannot) be connected to the same signal. The improper signal may actually ___ a driver. It is necessary to split the audio signal into low and high frequencies. This is the function of a ___,
cannot
damage
cross over
Name two generic types of cross over that are common in sound reinforcement.
high level passive networks and low level passive networks.
Name the characteristics of passive high level cross overs and active, low level cross overs.
High: simple networks that are designed for high level, inserted between the power amp output and the drivers, sensitive to both source (driving), impedence and load impedence.
Low: designed to be inserted in the signal chain before the power amplifier, function at line level, another term for this is electronic cross over, since active cross overs divide up the total frequency range before the power amp, separate amplifiers channels are required for each driver or set of drivers.
High level passive cross over is made up of ___, ___ and ___. By amplifying the system with active, low level cross over removes these losses thus improving ___.
capacitors, inductors, and resisters.
sound system efficiency
Loud speaker specifications
The specifications of a driver/loud speaker system should give us ____. The main tributes that are normally given in loud speaker specifications are what five things?
all the basic information we need to use it in an application.
frequency response, power handing, sensitivity, impedence, and directional characteristics.
The difference between continuous power and peak power ratings is what?
Continuous power refers to the average power dissipated in the loud speaker often by continuous sine wave signal.
Peak power ratings refer to the maximum instantaneous (very short term) power that the speaker can handle.
Sensitivity Rating
What is it?
The efficiency rating of the driver.
i.e. dB SPL at one meter in front of the loud speaker, with a one watt input signal being the most common rating.
Directional control
Understanding of and control over a sound system’s dispersion is ___. What are the two reasons?
essential
Want the sound quality to be as consistent as possible throughout the audience area.
We don’t want to waste the available energy of the system by directing it where we don’t need it.
What are the characteristics of outdoor sound systems.
What are the characteristics of indoor sound systems.
Common to place loud speakers on either side of stage area, aimed towards the center rear.
Same loud speaker placement; aiming is more complicated by the presence of reflective surfaces, aiming the speakers 2/3 of the way back.
What is the preferred method to put connectors on?
Strip the wire, tin it with solder, and insert it through the hold in the binding post. Tighten the nut down on the wire.
Why must polarity of loud speaker connections be strictly observed?
If reversed in polarity, it will cancel part of the in phase loud speaker’s sound. Low frequency loud speakers may be destroyed when operated at high level.
