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High Output Systems
First we will define high output systems, as systems designed
for, and capable of, producing high SPLs (Volume) continuously.
Dance club systems, large DJ type systems, and full blown concert systems, all
qualify.
Components
Loudspeakers
High output systems typically rely on "horns", as much as
possible, to couple a driver (a moving diaphragm) to the surrounding
air. Nearly all professional high output loudspeakers, use mid and high
frequency horns. The size of low frequency horns often prohibits
their use, on all but the largest systems. The use of vented
sub-woofer boxes is typically the method of choice, for added
low frequency output.
Contemporary systems often use large "full range box" systems
(similar to the images shown above), supplemented by sub-woofers. Where more output is required,
multiple boxes are used or arrayed, to reach the sound level
required. Additional advantages of arrayed boxes are:
- The ability to control and/or adjust
the pattern (or dispersion) of sound output, with the geometry
of the array. The
interaction of the multiple boxes, causes useful lobeing of the
sound energy.---------------------------------
- Coupling of the closely spaced low frequency drivers,
reduces the systems low frequency cut-off, giving more "bang for the
buck" on the bottom end.
Speaker systems are available where microprocessors (DSP's)
monitor the loudspeaker system's components. The feedback from the
DSP allows
automatic adjustment of other system components (amps or limiters),
so the systems components will not be sacrificed by heavy handed operators.
Amplifiers
High power outputs are, of course, the rule for these systems.
Professional high wattage amps, must dissipate tremendous amounts of
heat, so large heat sink areas and cooling fans are typical. The
designer / user must insure adequate ventilation, if dependable,
long term operation is to be maintained.
As the systems become larger, power requirements quickly reach
into the "Stratosphere". Each 3db (a small) increase in output SPL,
requires a doubling of the system's power. It requires 10 watts to
produce a level slightly louder sound, than 5 watts will produce -
this is certainly not a big problem, in most cases. The situation is
considerably different however, if we are starting with 50,000
watts, and need a meaningful increase in output. At these levels,
even slight increases in sound output, cost tens (even hundreds) of thousands of dollars.
Amplifiers are also available with DSP (processor) cards, that
control the various functions and parameters, based on user
programming.
More to come ...
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