JBL Application Engineered Series Application Manual

Contents

-10-ARRAY TIPSModeling Arrays in RoomsThe arrays included in this array guide have been developed to provide good coverageconsistency throughout their specified range and balanced power response throughout theirbandwidth. They are arranged to produce systems that are easy to rig and meet commoncoverage and performance needs.To better understand how these arrays will work in a particular room, it is always preferred tomodel 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 agood 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 SystemsMany 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 followingprocedure:1) First, optimize the long-throw loudspeaker or system by itself (including separateLF). 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 thelong-throw device. For a mid-high downfill device, use the same high-pass asthe long-throw M/H high-pass. This is important since using differentcrossover points is detrimental to how the loudspeakers interact due to phasemismatches through the crossover regions.3) Level balance the downfill on-axis measurement to match the long-throwloudspeaker’s on-axis measurement. This should be done above 1 kHz, where bothdevices are clearly in the effective range of the waveguide. This may be done bymatching traces on an analysis system such as Smaart or TEF; or by simplyusing an SPL meter.4) With both long-throw and short-throw sections on, analyze the downfill regionagain. The additional energy in this region, which resulted from the combinedcontribution of the long-throw device(s) and the downfill device, may be reduced byadding broad parametric EQ cuts to the downfill loudspeaker.Note: The use of parametric filters introduces less phase shift between thelong-throw and downfill devices than raising the high-pass crossover point ofthe downfill loudspeaker. This ultimately creates a smoother transitionbetween the devices.