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ARRAY TIPS
Modeling Arrays in Rooms
The arrays included in this array guide have been developed to provide good coverage
consistency throughout their specified range and balanced power response throughout their
bandwidth. They are arranged to produce systems that are easy to rig and meet common
coverage and performance needs.
To better understand how these arrays will work in a particular room, it is always preferred to
model the room with EASE
or a similar type of predictive analysis tool. With these tools,
array orientation and angles can be adjusted to optimize their use in the room. It is also a
good way to determine how different elements of the system – multiple arrays and fills –
combine to produce the complete solution.
EASE models for selected arrays are available on the JBL web site.
Optimizing Long-throw/Short-throw Loudspeaker Systems
Many sound reinforcement applications call for loudspeakers to be arranged in a “long-
throw/short-throw” configuration. To set-up a system like this, we recommend the following
procedure:
1) First, optimize the long-throw loudspeaker or system by itself (including separate
LF). Store your optimized trace for later reference.
2) Optimize the short-throw (downfill) speaker by itself (with long-throw off).
Note: When using a full-range downfill device, use the same high-pass as the
long-throw device. For a mid-high downfill device, use the same high-pass as
the long-throw M/H high-pass. This is important since using different
crossover points is detrimental to how the loudspeakers interact due to phase
mismatches through the crossover regions.
3) Level balance the downfill on-axis measurement to match the long-throw
loudspeaker’s on-axis measurement. This should be done above 1 kHz, where both
devices are clearly in the effective range of the waveguide. This may be done by
matching traces on an analysis system such as Smaart
or TEF
; or by simply
using an SPL meter.
4) With both long-throw and short-throw sections on, analyze the downfill region
again. The additional energy in this region, which resulted from the combined
contribution of the long-throw device(s) and the downfill device, may be reduced by
adding broad parametric EQ cuts to the downfill loudspeaker.
Note: The use of parametric filters introduces less phase shift between the
long-throw and downfill devices than raising the high-pass crossover point of
the downfill loudspeaker. This ultimately creates a smoother transition
between the devices.
