JBL VTX B18 Series, Руководство пользователя

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VTX B
18 | User Manual
12 - FLOWN CARDIOID CONFIGURATIONS
B18 subwoofers can be suspended in cardioid configurations using the VTX A8 suspension accessories like the VTX A8 Array Frame,
the VTX A8 Mini Frame or the VTX A8 Suspension Bar. This chapter outlines good practices when using the B18 in flown cardioid con-
figurations.
12.1 - ARRAY CONFIGURATIONS
When used in flown cardioid configurations, B18s should be used in blocks of 3 or 4, and when possible, in symmetric (top to bottom)
arrangements. Symmetry ensures that the pattern produced by the array is axially symmetric with the physical array allowing for a more
predictable coverage and aiming. None symmetric arrangements can be created, but should always be modeled in LAC-III first to ensure
that the cancellation part of the array falls outside any of the audience areas.
The example below shows the difference between a F-R-F and a F-F-R array. As shown in the SPL maps below, when a rear-facing
subwoofer is placed at the bottom of the array, the frontal coverage is tilted upwards and the rejection zone can fall within the audience
areas which can have undesirable effects.
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Example 2 : 3x VTX B18 in an asymmetric configuration (front-front-rear)
Example 1 : 3x VTX B18 symmetrically arranged (front-rear-front)